Byproduct Metals and Rare-Earth Elements Used 

In the Production of Light-Emitting Diodes—

Overview of Principal Sources of Supply and 

Material Requirements for Selected Markets

Scientific Investigations Report 2012–5215

U.S. Department of the Interior

U.S. Geological Survey
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Byproduct Metals and Rare-Earth Elements Used 

in the Production of Light-Emitting Diodes—

Overview of Principal Sources of Supply and 

Material Requirements for Selected Markets

By David R. Wilburn

Scientific Investigations Report 2012–5215

U.S. Department of the Interior

U.S. Geological Survey
U.S. Department of the Interior

KEN SALAZAR, Secretary

U.S. Geological Survey

Marcia K. McNutt, Director

U.S. Geological Survey, Reston, Virginia: 2012

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Suggested citation:

Wilburn, D.R., 2012, Byproduct metals and rare-earth elements used in the production of light-emitting diodes—

Overview of principal sources of supply and material requirements for selected markets: U.S. Geological Survey 

Scientific Investigations Report 2012–5215, 15 p., at http://pubs.usgs.gov/sir/2012/5215/.
iii

Contents

Abstract...........................................................................................................................................................1

Introduction.....................................................................................................................................................1

Sources and Supplies of Selected Mineral Commodities Used in Light-Emitting Diodes.................4

Arsenic....................................................................................................................................................4

Gallium....................................................................................................................................................5

Indium .....................................................................................................................................................5

Rare-Earth Elements.............................................................................................................................6

Light-Emitting Diode Component and Manufacturing Supply Chain.....................................................7

Substrate Manufacturing ....................................................................................................................7

Inorganic Semiconductor Manufacturing........................................................................................7

Epitaxial Process...................................................................................................................................8

Phosphor Manufacturing ....................................................................................................................9

Light-Emitting Diode Assembly and Packaging...............................................................................9

Market and Technology Trends...................................................................................................................9

Life Cycle Dynamics ....................................................................................................................................10

Byproduct Material Requirements for Selected Light-Emitting Diode Markets ...............................10

Summary........................................................................................................................................................12

Selected References...................................................................................................................................13

Figures

1. Structure of a light-emitting diode chip....................................................................................2

2. Periodic table of elements ..........................................................................................................3

3. Principal components of A, low-power and B, high-power light-emitting diodes ............4

4. Supply chain for selected byproduct raw materials, key manufactured components, 

and assembly facilities for the light-emitting diode industry ................................................8

Tables

1. Selected sources of lighting for light bulbs producing a similar light intensity measured 

in lumens ......................................................................................................................................10

2. Material requirements of selected metals for selected light-emitting diode markets for 

2010 and 2014...............................................................................................................................11

Conversion Factors

Multiply By To obtain

Length

millimeter (mm) 0.03937 inch (in)

Area

square kilometer (km2

) 0.3861 square mile (mi2)

Mass

ton, metric (t) 1.102 ton, short (2,000 lb)

Energy

joule (J) 0.0000002 kilowatthour (kWh)
iv

Acronyms

(Ce,La)CO3(F,OH) bastnäsite

(Ce,La,Nd,Th)PO4 monazite

Al2O3 alumina

As2S3 orpiment

AsS realgar

Ce cerium

CFL compact fluorescent light

DOE U.S. Department of Energy

Eu europium

GaAs gallium arsenide

GaAsP gallium arsenide phosphide

GaN gallium nitride

GaP gallium phosphide

HB high brightness

InGaN indium gallium nitride

La lanthanum

LCD liquid crystal display

LED light-emitting diode

lm/W lumens of visible light per watt of electricity consumed

mÅ milliangstrom

MOCVD metal-organic chemical vapor deposition

nm nanometers

OLED organic light-emitting diode

REE rare-earth element

SiC silicon carbide

Tb terbium

UNEP United Nations Environmental Programme

Y yttrium

YAG yttrium aluminum garnet
Byproduct Metals and Rare-Earth Elements Used in 

the Production of Light-Emitting Diodes—Overview of 

Principal Sources of Supply and Material Requirements 

for Selected Markets

By David R. Wilburn

Abstract

The use of light-emitting diodes (LEDs) is expanding 

because of environmental issues and the efficiency and cost 

savings achieved compared with use of traditional incandescent 

lighting. The longer life and reduced power consumption of some 

LEDs have led to annual energy savings, reduced maintenance 

costs, and lower emissions of carbon dioxide, sulfur dioxide, 

and nitrogen oxides from powerplants because of the resulting 

decrease in energy consumption required for lighting applications 

when LEDs are used to replace less-energy-efficient sources.

Metals such as arsenic, gallium, indium, and the rare-earth 

elements (REEs) cerium, europium, gadolinium, lanthanum, terbium, and yttrium are important mineral materials used in LED 

semiconductor technology. Most of the world’s supply of these 

materials is produced as byproducts from the production of aluminum, copper, lead, and zinc. Most of the rare earths required 

for LED production in 2011 came from China, and most LED 

production facilities were located in Asia.

The LED manufacturing process is complex and is 

undergoing much change with the growth of the industry and 

the changes in demand patterns of associated commodities. In 

many respects, the continued growth of the LED industry, particularly in the general lighting sector, is tied to its ability to 

increase LED efficiency and color uniformity while decreasing the costs of producing, purchasing, and operating LEDs. 

Research is supported by governments of China, the European 

Union, Japan, the Republic of Korea, and the United States. 

Because of the volume of ongoing research in this sector, it is 

likely that the material requirements of future LEDs may be 

quite different than LEDs currently (2011) in use as industry 

attempts to cut costs by reducing material requirements of 

expensive heavy rare-earth phosphors and increasing the sizes 

of wafers for economies of scale. Improved LED performance will allow customers to reduce the number of LEDs in 

automotive, electronic, and lighting applications, which could 

reduce the overall demand for material components.

Non-Chinese sources for rare earths are being developed, 

and some of these new sources are likely to be operational in 

time to meet increasing demand for rare earths from the LED 

sector. Because most LED component production and manufacturing occurs in Asia and many LED producers have established 

supply contracts with Chinese producers of rare earths, a significant amount of the metallic gallium, indium, and the rare earths 

used for LED production will likely continue to come from 

Chinese sources at least for the next 5 years; however, a greater 

amount of these materials are now being processed in Japan, the 

Republic of Korea, and Taiwan. As non-Chinese sources of rare 

earths come into production, these new mines are likely to be 

sources of light REEs, but China will likely remain the leading 

source of supply for the heavy REEs suitable for use as LED 

dopants and phosphors at least for the next few years. Increased 

research in the development of phosphors that use smaller 

amounts of or different REEs is intended to reduce dependence 

on rare earths from China. Supply disruption of rare earths 

and other specialty metals could take place if China’s specialty 

metal exports are redirected to domestic markets.

The cost of recovery is high and the lifespan for LEDs 

is comparatively long; thus, the LED waste volume was low 

in 2010, and few LEDs were recycled. The minute metal 

content of LEDs leads to a high cost for recovery, so recycling 

of LEDs outside of electronic waste is unlikely in the near 

term, although some LED producers are evaluating recycling 

options. Recycling of metals from LEDs in electronic waste 

is possible if the costs of recovering metals are justified by 

demand and metal prices.

Introduction

Light-emitting diode (LED) use is increasing in automotive, electronics, and lighting display applications and is 

expected to increase in general lighting applications in response 

to U.S. Government regulation, growing demand, and technological improvements. An adequate and reliable supply of raw 

materials is essential to meet this increasing demand for LEDs. 

Goals of increasing domestic and global energy independence, 

minimizing the economic effects of rising fossil fuel costs, and 
2 Byproduct Metals and Rare-Earth Elements Used in the Production of Light-Emitting Diodes

reducing greenhouse global gas emissions have contributed 

to government policy decisions placing greater emphasis on 

the development and implementation of devices that are more 

energy efficient. Currently (2011), the traditional incandescent 

light bulb typically produces 15 lumens of visible light per 

watt of electricity consumed (lm/W), and only about 5 percent 

of the electrical energy that goes into the bulb is converted to 

visible light (a measure of efficiency). The incandescent light 

bulb has a relatively short life span of 750 to 2,000 hours. Thus, 

it requires more energy and is more expensive to operate than 

newer types of lighting, such as halogen incandescent bulbs, 

compact fluorescent lights (CFLs), LEDs, or organic lightemitting diodes (OLEDs) (Humphries, 2008; U.S. Department 

of Energy, 2011a, b). Regulations restricting the sale of incandescent bulbs in Australia, Brazil, the European Union, and 

other areas began to be implemented in 2005. The United States 

enacted regulations halting the manufacture or export of incandescent bulbs in 2007. The Energy Independence and Security 

Act of 2007 (Public Law 110–140) set standards for increasing 

the energy efficiency of light bulbs by 30 percent. This would 

phase out most traditional incandescent light bulbs by 2012 or 

2014. China, the world’s leading producer of energy-efficient 

light bulbs, announced plans in 2011 to replace the 1 billion 

traditional incandescent bulbs it uses annually with more energy 

efficient types within 5 years (Branigan, 2011).

The U.S. Department of Energy (DOE) is legally required 

to ensure that manufacturers comply with the standards set 

by the U.S. legislation. Industry has responded by investing 

$120 million in LED research and development for lighting. 

LEDs, one type of solid-state lighting technology, consume 

less energy per lumen than traditional incandescent lighting. In 

an effort to reduce the cost of LED lighting, the DOE has been 

authorized by the U.S. Congress to invest up to $37 million 

for in manufacturing research and development on solid-state 

lighting, including high-brightness (HB) LEDs (U.S. Department of Energy, 2010b).

Although CFL technology provides an interim replacement 

device for incandescent bulbs in the general lighting market 

because of the lower cost, longer life (8,000 hours), and improved 

energy efficiency (typically 63 lm/W in 2010) of CFLs (U.S. 

Department of Energy, 2011a,b), CFLs contain mercury; LEDs 

do not and have in addition a broader range of applications than 

CFLs. As of 2009, a cool (more than 4,000 degrees kelvin (K)) 

white LED typically produced 60 to 92 lm/W, and a warm (less 

than 4,000 K) white LED typically produced 27 to 54 lm/W over 

an estimated useful life of 25,000 to 50,000 hours (U.S. Department of Energy, 2009a,b). The potential for LED technology to 

produce high-quality white light with a very high energy efficiency is being evaluated by much research and development.

LEDs are semiconductor devices that emit light when 

an electric current passes through the semiconductor chip in a 

single direction, converting 20 to 30 percent of the power into 

visible light. Figure 1 shows the generalized structure of an 

LED. Diodes in general are made up of thin layers of semiconductor material; one layer will have an excess of electrons 

(n-layer), and the subsequent layer will have a deficit of electrons, or “holes” (p-layer). When an electrical current is applied 

to a diode, electrons (negative) flow one way across the diode, 

and holes (positive) flow in the opposite direction across the 

diode. The holes exist at a lower energy level than the electrons, 

so when an electron falls, it loses energy, which is emitted as 

a light photon. The distance of the gap determines the energy 

level and wavelength frequency. Conventional LEDs are constructed using a variety of inorganic materials in groups IIIA, 

IIIB, IVA, and VA of the periodic table (fig. 2). Combinations 

of these materials are selected to produce light of a characteristic wavelength and color. The elements used most for LEDs 

include aluminum, arsenic, gallium, indium, and phosphorus. 

p-contact

n-contact

Substrate layer Commonly sapphire or silicon carbide 

n-layer

p-layer p-type dopants

n-type dopants

Active epitaxial layer (p-n junction)

Anode (+) 

Cathode (-) 

Electricity

Semiconductor

materials 

Light output Light output

Figure 1. Structure of a light-emitting diode chip.
Introduction 3

1

H

Hydrogen

4

Be

Beryllium

3

Li

Lithium

11

Na

Sodium

12

Mg

Magnesium

19

K

Potassium

20

Ca

Calcium

21

Sc

Scandium

22

Ti

Titanium

23

V

Vanadium

24

Cr

Chromium

25

Mn

Manganese

26

Fe

Iron

27

Co

Cobalt

28

Ni

Nickel

29

Cu

Copper

30

Zn

Zinc

2

He

Helium

5

B

Boron

6

C

Carbon

7

N

Nitrogen

8

O

Oxygen

9

F

Fluorine

10

Ne

Neon

13

Al

Aluminum

14

Si

Silicon

15

P

Phosphorus

16

S

Sulfur

17

Cl

Chlorine

18

Ar

Argon

31

Ga

Gallium

32

Ge

Germanium

33

As

Arsenic

34

Se

Selenium

35

Br

Bromine

36

Kr

Krypton

37

Rb

Rubidium

38

Sr

Strontium

39

Y

Yttrium

40

Zr

Zirconium

41

Nb

Niobium

42

Mo

Molybdenum

43

Tc

Technetium

44

Ru

Ruthenium

45

Rh

Rhodium

46

Pd

Palladium

47

Ag

Silver

48

Cd

Cadmium

49

In

Indium

50

Sn

Tin

51

Sb

Antimony

52

Te

Tellurium

53

I

Iodine

54

Xe

Xenon

55

Cs

Cesium

56

Ba

Barium

72

Hf

Hafnium

73

Ta

Tantalum

74

WTungsten

75

Re

Rhenium

76

Os

Osmium

77

Ir

Iridium

78

Pt

Platinum

79

Au

Gold

80

Hg

Mercury

81

Ti

Thallium

82

Pb

Lead

83

Bi

Bismuth

84

Po

Polonium

85

At

Astatine

86

Rn

Radon

118

Uuo

Ununoctium

117

Uus

Ununseptium

116

Uuh

Ununhexium

115

Uup

Ununpentium

114

Uuq

Ununquadium

113

Uut

Ununtrium

112

Cn

Copernicium

111

Rg

Roentgenium

110

Ds

Darmstadtium

109

Mt

Meitnerium

108

Hs

Hassium

107

Bh

Bohrium

106

Sg

Seaborgium

105

Db

Dubnium

104

Rf

Rutherfordium

88

Ra

Radium

87

Fr

Francium

57

La

Lanthanum

58

Ce

Cerium

59

Pr

Praseodymium

60

Nd

Neodymium

61

Pm

Promethium

62

Sm

Samarium

63

Eu

Europium

64

Gd

Gadolinium

65

Tb

Terbium

66

Dy

Dysprosium

67

Ho

Holmium

68

Er

Erbium

69

Tm

Thulium

70

Yb

Ytterbium

71

Lu

Lutetium

89

Ac

Actinium

90

Th

Thorium

91

Pa

Protactinium

92

U

Uranium

93

Np

Neptunium

94

Pu

Plutonium

95

Am

Americium

96

Cm

Curium

97

Bk

Berkelium

98

Cf

Californium

99

Es

Einsteinium

100

Fm

Fermium

101

Md

Mendelevium

102

No

Nobelium

103

Lr

Lawrencium

IA Group

1

IIA

2

IIIB IVB VB VIB VIIB VIII IB IIB

IIIA IVA VA VIA VIIA

VIIIA

3

4

5

6

7

Peroid

58

Ce

Cerium

Atomic

Number

Symbol

Name

EXPLANATION

Indicates elements used

in conventional LEDs

Figure 2. Periodic table of elements; modified from Dragoset and others (2011). The highlighted elements (in blue) in groups IIIA, IIIB, 

IVA, and VA indicate the principal materials used in the manufacture of conventional light-emitting diodes.

Different semiconductor materials (called substrates) and different impurities (dopants) introduced into the LED manufacture 

create the required electron density to generate the desired color 

produced by the LED (Casiday and Frey, 2007).

Historically, low-power LEDs of the through-hole design 

(fig. 3A) have been the most widely used type of LED. This 

type of low-brightness LED typically has a chip width of 0.25 

millimeter (mm) and is generally used in indicator lamps for 

automobiles and electronic devices, signage, low-intensity 

lighting applications, and low-power, focused-light applications, such as in the backlighting of portable electronic devices 

(Perkins, 2009). More recently, surface-mounted high-power 

LED chips with a width ranging from 0.1 to 3 mm and a wider 

emitted light angle (fig. 3B) are used in HB lighting applications in which individual LEDs are connected together in a 

bar, grid, or string assembly, such as that used in automobile 

dashboard lighting and large lighting displays. LEDs are often 

produced to conform to individual customer specifications, so 

electrical specifications, component materials, and LED sizes 

vary considerably based on application and customer needs.

The components of the most widely used types of LEDs 

(fig. 3) consist of the semiconductor chip, a metallic frame on 

which the chip is mounted, and the plastic encapsulation material surrounding the chip assembly. Semiconductor materials 

commonly used in LEDs include gallium arsenide (GaAs) or 

gallium arsenide phosphide (GaAsP), gallium nitride (GaN), 

indium gallium nitride (InGaN), gallium phosphide (GaP), and 

(or) silicon carbide (SiC). Metals commonly found in the frame 

for the LED chip include aluminum, chromium, copper, iron, 

lead, nickel, and (or) zinc. Gold and silver are often used in the 

metal contacts of the LED (How Products Are Made!, 2011).

Low-brightness (with a wavelength ranging from 0.00001 

to 0.002 nanometer (nm), or 1 to 20 milliangstrom (mÅ)), colored LEDs have been produced since the 1960s. The development of blue LEDs in the 1990s enabled the development of 

the first white LEDs made by coating blue LEDs with a phosphor. Other white LEDs were developed in the late 1990s by 

combining blue, red, and yellow-green LEDs. Medium-brightness LEDs (0.002 to 0.01 nm (20 to 100 mÅ)) were developed 

within the past decade for use in light panels, emergency 
4 Byproduct Metals and Rare-Earth Elements Used in the Production of Light-Emitting Diodes

A. Low-powered LED B. High-powered LED

LED chip

PC board

Cathode lead

LED chip

Cathode lead Lens

Silicon

submount

Thermal heat sink

Outer package Bond wire

Figure 3. Principal components of A, low-power and B, highpower light-emitting diodes (LEDs); modified from Energy Star 

(undated).

lighting, and automobile taillights; HB LEDs (0.01 to 0.1 nm 

(100 mÅ to 1 angstrom (Å))) are used primarily in televisions 

and cellular and mobile electronic devices. As of 2009, based 

on a global market value of $5.7 billion, the principal markets 

for all types of LEDs were signage, displays, and signals (38 

percent), cellular and mobile applications (32 percent), general 

lighting (18 percent), automotive (9 percent) and televisions 

and backlighting (3 percent). Short-term growth in LED use 

by 2015 is expected to be in backlighting and solid-state lighting sectors (Young and Low, 2009).

The LED industry uses a wide and growing range of 

phosphor materials to convert the light emitted from LED 

chips into different wavelengths of the lighting spectrum. 

Unlike dopants, phosphors are coatings that are applied to the 

LED chip during the packaging process. LED manufacturers 

rely on their supply of phosphor materials as a crucial aspect 

of the production process. The most common use is the combination of a blue LED chip with one or more phosphors to 

create a white LED. Many of the phosphors used in LEDs contain rare-earth elements (REEs), although the purity of REEs 

in LED phosphors is reported to be about 10 times less than 

phosphors used in cold-cathode fluorescent lamps (CCFLs) 

and liquid-crystal display (LCD) televisions (Bruce Hillman, 

Intematix Corporation, oral commun., November 18, 2011).

Because impurities can distort the color characteristics of 

phosphors, REEs used in phosphors must be 99.999 percent 

pure (U.S. Department of Energy, 2010c). In order to achieve 

such high purity, the processing of REEs intended for use as 

phosphors requires more processing stages than phosphors for 

other markets and increases the cost of producing REEs for 

this application.

OLED technologies are a flat light-emitting technology 

created by placing a series of organic thin films between two 

conductors. Light is emitted when electrical current is applied. 

Because OLEDs emit light, they do not require a backlight, so 

they are brighter, more energy efficient (consume less power), 

and thinner than LCDs, which require a white backlight. This 

technology has been used principally in television screens, computer monitors, and small electronic devices, such as cell phones 

and PDAs (OLED-Info, 2011). OLEDs typically emit less 

light per area than inorganic solid-state LEDs, which are often 

designed for point source lighting. Development of efficient 

OLED systems for a broad range of applications will likely lag 

LED systems by about 5 years (Whitaker, 2011b). Because the 

byproduct materials used in OLEDs are similar to those used in 

LEDs and because the use of OLEDs in a broad array of applications will not likely occur before 2020, this report does not 

include a separate treatment of OLED materials use.

Sources and Supplies of Selected 

Mineral Commodities Used in LightEmitting Diodes

LEDs are made up of a variety of primary metals and 

minerals produced as byproducts from the production of other 

metals. Metals such as aluminum, chromium, copper, gold, 

iron, lead, nickel, silver, and zinc and organic components are 

excluded from this analysis because production is widespread 

and published literature on the sources and supply of these 

metals is readily available. This report describes the sources 

of supply of several mineral commodities that are not widely 

produced or produced in limited quantities but considered 

critical for the production of LEDs and LED phosphors. It 

also provides general estimates of material requirements based 

on reported or anticipated LED demand. Byproduct materials 

used in LEDs evaluated in this study include arsenic, gallium, 

and indium, as well as the REEs cerium, europium, gadolinium, lanthanum, terbium, and yttrium.

Arsenic

Arsenic is found in low concentrations in most soils and 

in higher concentrations associated with copper, lead, and zinc 

ores. Because of the health implications to humans and the 

environment, the extraction, recovery and processing, use, and 

disposal of arsenic are highly regulated. The United States was 

a leading producer of arsenic metal until 1985, when the Asarco 

Incorporated copper smelter in the State of Washington was 

closed (Bleiwas, 2000). In China, Peru, and the Philippines, 

arsenic is recovered from the minerals orpiment and realgar. 

Arsenic is also produced from deposits in Chile and Morocco 

by the reduction of arsenic trioxide obtained from flue dusts 

derived from smelting copper, gold, lead, and silver. In 2010, 

commercial-grade (99 percent pure) arsenic metal was produced from arsenic trioxide in China (47 percent), Chile (21 

percent), Morocco (15 percent), and Peru (8.5 percent), with 

minor amounts from seven other countries. There has been no 

production of arsenic trioxide or arsenic metal in the United 

States since 1985, although the Nation remained the world’s 

leading consumer of these products in 2010 (Brooks, 2011). The 

United States imports arsenic trioxide primarily from China and 

Morocco and high-purity (99.9999 percent pure) arsenic metal 
Sources and Supplies of Selected Mineral Commodities Used in Light-Emitting Diodes 5

from China and Japan for use in the manufacture of chemicals, 

semiconductors, and pressure-treated wood products.

High-purity arsenic metal is used to produce GaAs, 

InGaN, or GaAsP semiconductors. The GaAsP semiconductor 

is commonly used to produce red, orange, and yellow LEDs 

used in indicator lamps, automotive applications, signage, and 

traffic signals.

Because arsenic concentration in LEDs is reportedly lower 

than what is required by Federal and State guidelines, arsenic 

in LEDs does not pose a safety hazard. A supply disruption is 

not anticipated unless regulations governing arsenic production 

and processing facilities in China and other producing countries 

are modified, delaying production or increasing its cost enough 

to impair the production of LEDs. The recycling of electronic 

waste is a potential source of secondary arsenic and many 

other materials. Close monitoring of metal recovery facilities 

will ensure that some of the metals potentially recoverable 

do not become environmental hazards or pose risks to human 

health. U.S. and foreign mineral processing companies prefer 

to process electronic scrap where the precious metal content is 

high and the risk for emission or exposure to deleterious elements such as arsenic is low; higher risk waste material is often 

shipped overseas for processing (Bleiwas and Kelly, 2001).

Gallium

Most of the world’s supply of gallium originates as an 

impure byproduct recovered during the aluminum production 

process. Where gallium has replaced aluminum in rock-forming silicates, such as bauxite, its concentration typically ranges 

from 10 to 160 parts per million. Gallium is recovered primarily from deposits in Australia (33 percent), China (19 percent), 

Brazil (15 percent), and India (8.5 percent) (Bray, 2011). A 

small amount of gallium is recovered in Japan during the zinc 

refining process. No primary gallium recovery was reported in 

the United States in 2010. In 2011, the estimated production 

capacity of gallium metal refined from ores worldwide was 

about 180 metric tons per year (t/yr), with China producing an 

estimated 93 metric tons (t) in 2011 (Brian Jaskula, gallium 

commodity specialist, U.S. Geological Survey, oral commun., 

October 31, 2011). Other leading producers of gallium metal 

are Germany, Kazakhstan, the United Kingdom, and Ukraine. 

Some low-grade gallium metal is refined onsite, but much of 

it is sold and processed into gallium metal alloys of varying 

purities elsewhere. Gallium is recovered from new scrap from 

the gallium arsenide production process.

The recycling capacity of gallium worldwide is about 200 

t from GaAs semiconductors and optoelectronic devices (laser 

diodes, LEDs, photo detectors, and solar cells) primarily in 

Japan, Canada, and the United States. The amount of potentially recoverable gallium is larger than the amount actually 

recovered because, where gallium concentration is too low to 

be economically recoverable, it is disposed of as waste during 

aluminum processing.

More than 97 percent of the gallium consumed in the 

United States in 2010 was in the form of GaAs or GaN. 

Optoelectronic devices accounted for 30 percent of the GaN 

consumption in the United States in 2010. The United States 

imported 166 t of doped 1

 GaAs wafers and 63 t of undoped 

wafers for use in LEDs in 2010 (Brian Jaskula, gallium commodity specialist, U.S. Geological Survey, oral commun., October 31, 2011). Consumption of gallium for LEDs in the United 

States in 2010 (based on data on imports of wafers reported by 

the U.S. International Trade Commission (2011) increased by 

64 percent from 2009 owing to the growth of the LED market. 

Supply of gallium and indium used as precursor materials in the 

metal-organic chemical vapor deposition (MOCVD) process 

commonly used to produce LED wafers was reported during 

the second half of 2010 (Hatcher, 2010), and capacity expansions for facilities that produce LED wafers using the MOCVD 

process are in progress (Cooke, 2010). An increase in gallium 

demand beyond the current (2011) capacity can be satisfied by 

further expansion of recovery circuits at existing alumina facilities and (or) increased recycling of GaAs wafers.

Indium

Approximately 570 t of indium metal produced worldwide in 2010 came from primary sources (Tolcin, 2011b). 

Most of the world’s supply of indium originates as a byproduct 

of the processing of zinc ores mined in China, Peru, Canada, 

Australia, and the United States (in decreasing order of quantity of indium recovered). Indium can also be recovered as a 

byproduct of mining copper, lead, tin, and precious metals in 

many countries, but production of indium from these sources 

is minor. Indium metal is produced primarily in Canada, 

China, Japan, and the Republic of Korea. China produces 

about 52 percent of the world’s refined indium, primarily from 

domestic sources. The Republic of Korea produces 14 percent 

of the world’s refined indium from imported concentrates, 

Japan produces 12 percent from imported concentrates, and 

Canada produces about 6 percent from domestic sources and 

from imports from the United States (Tolcin, 2011a).

Raw indium materials are often extracted in one country 

and processed at a second location, and final products containing indium, such as LEDs, are manufactured at a third location 

because few companies that produce indium operate fully integrated mining, processing, and manufacturing facilities. Japan 

Energy Corporation is the largest integrated indium producer 

in the world and produces indium metal of varying grades 

from zinc refining operations as well as indium phosphide 

for use in LED semiconductors. Hunan Nonferrous Metals 

Corporation Limited is the largest integrated metals producer 

in China, and Umicore S.A. of Belgium produces high-purity 

indium products for the semiconductor industry from internal and purchased sources. Most mining companies produce 

1

Doping refers to the process of introducing impurities in the material to 

generate the desired electrical characteristics and wavelength (color).
6 Byproduct Metals and Rare-Earth Elements Used in the Production of Light-Emitting Diodes

indium metal compounds of lower purity that are further 

upgraded at specialty refineries in China, Japan, the Republic 

of Korea, and the United States.

The principal use of indium is in the production of flatpanel LCD televisions. The use of LEDs in backlit LCD televisions is growing, so consumption for indium in LCD televisions is expected to increase at a rate greater than the 5 percent 

growth rate in consumption of indium from 2009 to 2010 

(Tolcin, 2011b). With the increase in the demand for indium, 

exploration of deposits containing high amounts of indium 

has become more attractive for development, supply is being 

increased by adding or expanding additional recovery circuits, 

and recovery of indium from tailings and slags and recycling 

of indium from flat-panel LCD televisions is also increasing. Increased demand in 2010 for precursor materials such 

as indium in MOCVD production led to a short-term supply 

shortage that year; this shortage was expected to be resolved 

by the end of 2011 as new capacity was expected to come 

into production (Cooke, 2010; Hatcher, 2010). Because LCD 

televisions are a relatively new consumer product and the life 

of an LCD television and most of its components is reported to 

be more than 15 years, little, if any, recycling of indium from 

LCD televisions occurred in 2010. Research patents have been 

issued for technology to recycle indium from zinc tailings and 

slag and to recover indium from LCD televisions.

The United Nations Environmental Programme has called 

for rapid improvements in the recycling rates of a group of metals 

that include gallium, lithium, and neodymium (United Nations 

Environmental Programme, 2010). The increase in demand for 

specialty metals, such as gallium and indium, in LED manufacturing has led to efforts to improve access to these commodities. 

Short-term concerns over possible gallium and indium shortages 

for use in critical high-technology industries contributed to Japan 

setting up a 42-day stockpile of gallium and indium in 2009 

(Tolcin, 2011a). The Republic of Korea set up a stockpile for 

these elements in 2006 and may increase the stockpile by 2016 

if warranted. Gallium and indium were among the 10 rare metals 

that the China’s State Bureau of Material Reserve [China] was 

considering for stockpiling in 2010 (Cooke, 2010).

Based on available data, the supply of indium from 2012 

through 2015 will likely be able to meet anticipated industrial 

demand unless China imposes additional export restrictions on 

these materials, which are so important to many high-technology industries.

Rare-Earth Elements

The supply chain for REEs generally consists of mining, 

separating, refining, alloying, and product manufacturing. As 

of 2010, about 97 percent of mining and concentration of rare 

earths, 97 percent of separation of REEs from concentrates to 

oxides, and almost 100 percent of the refining of oxides to metals has taken place in China (Schüler and others, 2011). REEs 

commonly used in LED phosphors include cerium, europium, 

lanthanum, terbium, and yttrium. China consumes 80 percent of 

the world’s supply of phosphor raw materials and produces most 

of the phosphor powders intended for fluorescent bulbs, CFLs, 

and LEDs used in lighting applications (U.S. Department of 

Energy, 2010c). Because China is the world’s primary source of 

REEs and has implemented a quota system that limits the export 

of these unprocessed materials, the future accessibility and supply of rare earths are of concern to industry and governments 

(Whitaker, 2011a). In an effort to increase domestic consumption of rare earths in its product manufacturing sectors, China’s 

Government has gradually reduced the export quota from about 

47,000 t of rare-earth oxide (REO) equivalent in 2000 to 22,500 

t in 2010 from domestic producers and traders and 7,700 t from 

joint ventures of Chinese and foreign companies (Tse, 2011). 

In 2008, about 9,000 t of REOs was used in phosphor powders 

(Bade, 2010), but only a small fraction of the total production 

of phosphor powder is thought to have been used in LEDs. A 

variety of phosphors are manufactured for use in LEDs; the most 

common LED phosphor is yttrium aluminum garnet (YAG) 

doped with cerium (Setlur, 2009b; Snob, 2011). New phosphors 

are being developed that are less expensive, provide truer colors, 

and use smaller quantities of REEs. Material alternatives to rareearth phosphors used in semiconductor applications that are presently being researched include alkali earth hydrides and nitrides, 

manganese-doped fluorides, or semiconductor nanocrystals 

(Setlur, 2009a; Erdem and Demir, 2011).

Worldwide, most REEs are located in deposits of the 

minerals bastnäsite and monazite. Although primary and (or) 

byproduct bastnäsite has been mined and (or) recovered in 

China and the United States and byproduct monazite has been 

mined from deposits in Australia, Brazil, China, India, and 

Malaysia, more than 95 percent of the global production of 

REEs in 2010 came from China from bastnäsite, monazite, 

xenotime ores, and ion-adsorption clay (Schüler and others, 

2011). REEs have also been recovered as a byproduct of copper, gold, iron, phosphate, and uranium mining and processing. Resources of rare earths are geographically diverse, but 

separation of the individual rare earths from the ore requires 

a sequential series of concentration steps. Only a few Chinese 

producers have the capability to process REEs into finished 

materials. Concentrations of individual REEs differ from 

site to site. Most of the deposits of rare earths contain higher 

concentrations of light REEs (cerium, europium, gadolinium, 

lanthanum, neodymium, praseodymium, promethium, and 

samarium) than heavy REEs (dysprosium, erbium, holmium, 

lutetium, terbium, thulium, ytterbium, and yttrium). Deposits that contain significant quantities of the light rare earths 

cerium, europium, and lanthanum and the heavy rare earths 

gadolinium, lutetium, terbium, and yttrium are those that are 

most likely to be sources of rare earths for LED production 

in the near future (Goonan, 2011). Deposits in China produce 

light and heavy REEs; ion-adsorption clays in China produced 

all the heavy rare earths used in 2010.

The Molybdenum Corporation of America’s (later 

Molycorp Inc.) Mountain Pass mine in California served as 

the predominant source of rare earths in the United States 

from 1965 to 1998. Molycorp ceased mine production in 1998 
Light-Emitting Diode Component and Manufacturing Supply Chain 7

as a result of regulatory problems with the main wastewater 

pipeline and low prices for rare earths. The processing facility 

remained open for the concentration, purification, and sale of 

previously mined stockpiles through 2002, when processing 

operations were suspended (U.S. Government Accountability 

Office, 2010). In 2007, the mine resumed sales of stockpiled 

materials, and mining recommenced in December 2010. Since 

1990, when the United States generated approximately 40 

percent of the world’s revenue of rare earths, the country has 

been primarily dependent on foreign sources for REEs and the 

products containing them (U.S. Department of Energy, 2011b). 

The announced acquisition of Neo Material Technologies Inc., 

with downstream rare earth processing facilities in China and 

Thailand, by Molycorp in 2012 would allow the company to 

again become an integrated producer of rare-earth products 

(Molycorp Inc., 2012).

Concerns about possible supply disruptions of rare earths 

have led to increased exploration for rare earths and stimulated 

development of several new mining and production facilities 

outside of China. The Mount Weld mine in Australia began 

production in 2011 and was expected to reach its full capacity 

of 10,500 t/yr of total REO equivalent in 2012. A new refinery in Malaysia with an initial annual production capacity of 

11,000 t/yr of rare-earth products was under construction and 

was scheduled to begin production in 2012. By 2013, production of REEs in the United States is expected to reach 19,050 

t/yr of REO equivalent when the Mountain Pass mine in California reaches full capacity.

The principal use of REEs in LEDs is in the phosphors 

used to generate the desired color. Although phosphors 

accounted for about 6 to 7 percent (8,000 to 9,000 t based on 

various estimates) of the total demand of 124,000 to 127,500 

t of REE in 2010 (Kingsnorth and Cox, 2010; Lynas Corporation Limited, 2011), the total amount of REEs used in LED 

phosphors in 2010 was estimated to be one to two orders of 

magnitude lower than the amount required for other sources 

of lighting, such as CFLs and linear fluorescent lamps, of 

equivalent light output (U.S. Department of Energy, 2011c). 

By 2014, total consumption of rare earths used for phosphors 

in lighting applications is anticipated to be 11,000 to 13,000 

t of REEs, still about 7 percent of total consumption of REEs 

(Kingsnorth and Cox, 2010). However, because of the lower 

REE content of LED phosphors when compared with some 

other lighting applications, growth of the LED industry for 

general lighting is likely to result in reduced consumption of 

REEs on a unit basis. This is one factor contributing to the 

increased use of LEDs in lighting (Bruce Hillman, Intematix 

Corp., oral commun., November 18, 2011).

In 2008, LEDs represented less than 2.4 percent of the 

global lighting market. However, development has led to a 

broader use for LEDs in this sector, and one estimate suggests 

that LEDs will account for about 8 percent of the lighting market in 2013 (Schüler, 2011). The effect of LED growth on REE 

consumption is expected to be small because LEDs use minute 

quantities of REEs in the phosphor compared with alternative 

lighting options (Hykawy and others, 2010).

Light-Emitting Diode Component and 

Manufacturing Supply Chain

The manufacturing process of LEDs is complex. As the 

industry grows, the markets change; as technology advances, 

the manufacturing processes change. An overview of the 

principal manufacturing steps and sources of key materials 

required for each step in the manufacturing processes currently 

(2011) in use are discussed below. Figure 4 summarizes the 

supply chain for selected byproduct raw materials, manufactured components, and assembly facilities for the LED 

industry.

Substrate Manufacturing

The manufacture of an LED begins with the growth of 

the lowest layer on which various semiconductors are grown. 

This base layer is called a substrate; common substrates 

include artificially grown sapphire, silicon carbide, and silicon. Most LEDs, particularly those intended to produce white 

light, use a sapphire substrate. To create the sapphire substrate, 

alumina is heated in a furnace to form a boule, from which 

a rod-shaped tube is extracted. Alumina is derived from the 

mineral bauxite, which is generally processed to high-purity 

(99.9999 percent) alumina (which in 2010 was processed 

primarily in Australia, Brazil, China, and India) before being 

shipped to substrate suppliers (Bray, 2011). Substrate production occurs primarily in Asia (about 67 percent was manufactured in China, Japan, the Republic of Korea, and Taiwan in 

2007), Europe (20 percent was in France and Russia in 2007), 

and the United States (13 percent in 2007) (Semiconductor 

Today, 2008). Ultra-thin wafers (about 0.25 mm (0.01 inch) 

thick) ranging from 50 to 200 mm (2 to 8 inches) in diameter 

are sliced from the tube, polished and packaged, then shipped 

to customers.

Because high-purity alumina is available only from a 

limited number of suppliers, increased demand for high-purity 

alumina in 2010 resulted in a sapphire wafer shortage in 2010. 

This shortage lasted through 2011 when additional capacity 

came online. At the end of 2010, consumption (measured in 

terms of 2-inch-equivalent wafer units) was estimated to be 

2,800 million units, while demand in 2011 was projected to be 

4,200 million units (China Optical Network, 2011).

Inorganic Semiconductor Manufacturing

Component metals are melted, combined, and extruded in 

a rod-shaped tube that is sliced into wafers in a process similar 

to sapphire substrate production. Semiconductor substrates of 

various compositions are selected based on the wavelength of 

light and color of LED desired and are then manufactured and 

layered on the substrate. An infrared light can be produced 

from a GaP substrate, a GaAsP substrate can generate yellow, 

orange, or red light of various wavelengths, and a gallium 
8 Byproduct Metals and Rare-Earth Elements Used in the Production of Light-Emitting Diodes

nitride (GaN) substrate can be used to produce blue light. GaN 

or InGaN substrates are commonly used in white LEDs when 

a blue LED is combined with a yellow phosphor to generate 

white light.

Epitaxial Process

The method used to manufacture semiconductors by 

depositing a series of thin layers of various component 

materials on a substrate is called epitaxy. The most common 

technology used to deposit these layers in LED manufacturing 

is MOCVD, which attaches compounds such as trimethyl gallium or trimethyl aluminum to the sapphire substrate to create 

the GaN or InGaN precursors for the blue LED, which is used 

in creating LEDs that emit white light. During this sequential 

process, minute quantities of dopant are added to create the 

LED with the specific electrical characteristics and wavelength 

desired. Currently (2011), the primary source of dopants used 

in the epitaxial process is China. A single epitaxial rod can 

then be sliced into wafers, each wafer yielding more than 

20,000 individual chips. The electrical contact pattern is then 

etched on the surface of each chip, and gold or silver contacts 

are attached.

More than 98 percent of the MOCVD equipment manufactured in 2010 was manufactured by three companies, Veeco 

Instruments Incorporated (United States, 63 percent of production), Aixtron SE (Germany, 28 percent), and Taiyo Nippon 

Sanso (Japan, 7 percent), all with manufacturing facilities in 

Asia (Matsumoto, 2011). Epitaxy production in 2010 took 

place in the Republic of Korea (31 percent), Japan (29 percent), Taiwan (16 percent), Germany (9 percent), the United 

States (9 percent), and China (6 percent) (Research in China, 

2011). The 50-mm (2-inch)-diameter wafer is currently (2011) 

the preferred standard unit for LEDs, although new technological advances are making the production of larger wafers more 

cost effective. By 2012, 100-mm (4-inch)-diameter wafers 

will likely be the substrate size of choice for LEDs. Larger 

150-mm (6-inch)-diameter wafers are also being developed 

by leading manufacturers (Business Wire, 2011; I-Mícronews, 

2011a). Economies of scale make larger wafers and thus LEDs 

more cost competitive. A single 2-inch-diameter wafer can 

yield 6,000 to 20,000 chips, while a 6-inch-diameter wafer 

can yield more than 100,000 chips. Variation in the number of 

Figure 4. Supply chain for selected byproduct raw materials, key manufactured components, and assembly facilities for the lightemitting diode industry. Data are as of 2009 and are compiled from reports in the U.S. Geological Survey Minerals Yearbook series 

(reporting for 1995–2010) and available information from trade publications.

Byproduct raw materials Manufactured components Light-emitting diode assembly

Arsenic

Byproduct of metal smelting:

China

Peru

Philippines

Byproduct of copper-gold mining:

Chile

Byproduct of cobalt mining:

Morocco

Production in arsenic trioxide:

China (47%)

Chile (21%)

Morocco (15%)

Peru (8.5%)

Gallium

Byproduct of bauxite mining:

Australia (33%)

China (19%)

Brazil (15%)

India (8.5%)

Byproduct of zinc refining:

Japan

Byproduct of metal production:

China (32%)

Germany (19%)

Kazakhstan (14%)

Japan (11%)

Russia (10%)

Other countries (14%)

Indium

Byproduct of zinc mining:

China

Peru

Canada

Australia

Byproduct of metal production:

China (52%)

Korea, Republic of (14%)

Japan (12%)

Canada (6.1%)

Rare earth elements

Cerium:

China (98%)

India (2%)

Gadolinium:

China (90%)

Russia (3.5%)

India (2.6%)

United States (2.6%)

Yttrium:

China (99%)

Sapphire substrate

Produced from alumina derived from bauxite mining

Substrate manufactured in:

Asia (67%)

Europe (20%)

United States (13%)

Metal-organic chemical vapor

deposition equipment

Manufactureing companies from:

United States (63%)

Germany (28%)

Japany (7%)

Manufactured In facilities located in Asia

Light-emitting diode wafers

Manufactured in:

Korea, Republic of (31%)

Japan (29%)

Taiwan (16%)

Germany (9%)

United States (9%)

China (6%)

Phosphors

Rare earths mined in China

Ore stockpiled in the United States

Powder produced in:

China

Germany

Taiwan

India

Light-emitting diode dies

Assembled in:

Asia (73%)

Germany (10%)

United States (10%)

Netherlands (7%)
Market and Technology Trends 9

chips produced per wafer results from variation in chip quality 

and breakage rate (How Products Are Made!, 2011).

A number of chemical companies are building or increasing their MOVCD process capacity using trimethyl gallium so 

that, by 2012, there may be an oversupply of wafers for lowend markets (Cooke, 2010; I-Mícronews, 2011b).

Phosphor Manufacturing

The LED industry uses a wide and growing range of 

phosphors to convert the light from LED chips into various 

wavelengths as required by the end-use application. Most 

of the rare earths used in the manufacture of silicate and 

oxide powders come from China. The phosphor powders are 

manufactured primarily in China, Germany, Taiwan, and India. 

Many of the large LED manufacturers have in-house phosphor 

manufacturing capability or have supply agreements with 

small-scale phosphor manufacturers. Manufacturers use patented processes in preparing phosphors with unique compositions for the same base powder, so phosphor composition in 

LEDs can vary significantly. Consequently, a binning process 

is used to store LEDs of similar composition and light-emitting characteristics.

LED phosphor manufacturing costs are high at the initial 

stage of LED development for some applications because 

of the relatively low demand for LED phosphor powder and 

LEDs, economy of scale issues, difficulty in achieving a 

suitable color consistency, and the high cost of REEs used in 

many phosphors. Medium- and high-purity REEs are necessary for phosphors used in lighting applications, increasing the 

cost to LED manufacturers. Ores containing multiple REEs 

must be refined such that each REE that is produced meets the 

specified purity level, an expensive process that few companies are willing to undertake (U.S. Department of Energy, 

2011a). The concentrated rare-earth product is usually shipped 

to a small number of phosphor manufacturers who further process the metals to ever higher levels of purity and (or) produce 

phosphor powders of various specifications. Powders are then 

sold to suppliers for global distribution, or LED manufacturers 

may create the desired phosphor in-house.

Research is ongoing to develop phosphors that use a 

smaller quantity of REEs per application. New nitride or 

silicate compositions are being tested, and phosphors substituting manganese for europium and those using lower amounts 

of europium are being developed to improve light quality and 

reduce consumption of rare earths (Setlur, 2009b).

Light-Emitting Diode Assembly and Packaging

LED assembly is completed during the packaging process 

by companies located in Asia (73 percent), Germany (10 percent), the United States (10 percent), and the Netherlands (7 

percent). During this stage of manufacturing, the phosphor is 

added to the LED, LED optics and wiring are completed, the 

die is encapsulated in plastic resin, and the LED is packaged 

for shipment to customers. Packages for high-power applications are created using large single wafers or multiple smaller 

wafers connected in series (I-Mícronews, 2011a).

Major producers have established sources of supply for 

raw materials, and new consumers to the market generally rely 

on smaller producers for their supply of materials and components.

Market and Technology Trends

The packaged LED market is expected to increase at a 

28 percent annual growth rate from 2009 through 2015. Initial 

growth from 2006 through 2008 was stimulated by small 

display applications, such as cell phones and other handheld 

devices. Industry growth from 2009 through 2015 will likely 

be driven by large LCD backlighting and automotive applications. One analyst suggests that the total LED die surface area 

required for LEDs used in LCD backlighting will increase 

from 6.3 billion square millimeters in 2009 to 51 billion 

square millimeters in 2015 (I-Mícronews, 2011b). Large-scale 

use of LEDs in general lighting applications will most likely 

take place after 2015. The degree and timing to which LEDs 

are used in the general lighting market depend on cost, public 

acceptance, quality, policy, and technology issues.

In 2010, more than 60 companies were involved in the 

manufacture of GaN-based LEDs, and additional companies began production in 2011. MOCVD tool installations 

in China are expected to increase from a cumulative total of 

323 tools in 2010 to more than 1,000 tools by the end of 2012 

(Whitaker, 2011b). The LED epitaxial manufacturing industry was expected to be consolidated by 2013, but production 

will likely continue primarily in China, Japan, the Republic 

of Korea, and Taiwan (I-Mícronews, 2011b). Dependence 

on Chinese rare earths for use in dopants and phosphors will 

probably continue in the short term; increased production of 

rare earths from non-Chinese sources and development of 

phosphors that use fewer REEs will likely reduce dependence 

on rare earths from China only slightly by 2015.

The DOE has established benchmarks for desired LED 

efficiency improvements and costs; the efficacy of cool white 

light bulbs containing LEDs are expected to increase from 134 

lm/W in 2010 to 224 lm/W in 2015 and 258 lm/W by 2020. 

Similarly, the efficacy2

 of warm white light bulbs containing 

LEDs are targeted to increase from 96 lm/W in 2010 to 202 

lm/W in 2015 and 253 lm/W by 2020. The average price of a 

cool white LED light bulb is targeted to decrease from $13.00 

per kilolumen in 2010 to $2.00 per kilolumen in 2015 and 

$1.00 per kilolumen in 2020. The average price of a warm 

white LED lamp is targeted to decrease from $18.00 per kilolumen in 2010 to $2.20 per kilolumen in 2015 and $1.00 per 

kilolumen in 2020 (Wright, 2011).

2

Efficacy refers to the amount of light produced against the power consumed to produce that amount of light. 
10 Byproduct Metals and Rare-Earth Elements Used in the Production of Light-Emitting Diodes

Life Cycle Dynamics

If LEDs are to become the principal replacement for the 

incandescent light bulb, a number of factors must be considered when comparing LEDs with other lighting technologies. Factors include consumer acceptance; energy, material, 

and cost requirements; environmental and toxicity concerns; 

government policies and subsidies; and recycling and disposal 

issues. Although the LED industry is still in the early stage of 

growth for some applications, several studies provide information on these issues.

A study conducted by Carnegie Mellon University in 

2008 suggests that the energy requirement for LED chip manufacture (excluding raw materials production and final light 

bulb assembly) is 0.02 to 0.08 kilowatthour (kWh) per LED 

chip or about 1 kWh for the entire LED module to be included 

in an ‘average’ retrofit light bulb with a life of 10,000 hours 

(Matthews and others, 2009). Humphreys (2008) developed 

estimates of the lifetime cost of ownership for various types of 

lighting, and key findings from this study are listed in table 1.

Unlike CFLs, lifetime estimates for LEDs are determined 

by estimating the useful life of an LED based on the length 

of time a LED maintains a specified level of its initial light 

output. For general lighting applications, the useful life is most 

often defined as the length of time it takes an LED to reach 70 

percent of its initial light output (L70). For other applications, 

a useful life of L50 (the length of time it takes an LED to reach 

50 percent of its initial light output) is often used. When LEDs 

are to be used as part of a lighting fixture, the effective lifetime 

is based on the failure of the first component, which often may 

not be the LED.

LEDs do not contain any mercury, which is found in 

CFLs, and thus they are not regulated as a hazardous waste 

by the U.S. Environmental Protection Agency. Some LEDs 

contain minute but detectable quantities of some metals that 

can be treated as hazardous waste when they exceed Federal 

or State regulatory limits (Lim and others, 2010; European 

Commission, 2011).

Because LEDs are small in size and have a comparatively long lifespan, the LED waste volume is low, and few 

LEDs are recycled. Because of the minute metal content of 

individual LEDs, recycling of LEDs is unlikely; however, it is 

possible that LEDs contained in electronic devices and televisions could be recycled along with other electronic waste if the 

costs of recovering metals contained in LEDs were justified by 

metal prices.

Byproduct Material Requirements for 

Selected Light-Emitting Diode Markets

Table 2 provides rough estimates of the amounts of nine 

byproduct metals found in LEDs for selected market applications. Estimates for 2010 and 2014 were developed based 

primarily on LED compositions reported by a study conducted 

by the University of California, Davis (Lim and others, 2010; 

Julie Schoenung, University of California, Davis, oral commun., October 7, 2011). LED demand estimates were developed by McKinsey & Company, Inc. (2011) and DisplaySearch, and numerous other sources of published information 

(PC Electronic Components, 2009; LEDs Magazine, 2010) 

and personal contacts. Composition data derived from the 

University of California, Davis study were assumed to report 

minimum content levels because the T1 three-quarter-size 

chips analyzed in the University of California, Davis study, 

while widely used, are of a smaller chip size than the LEDs 

that are used in some applications. Values reported in table 

2 should be considered as minimum approximations of the 

amount of the selected materials contained in LEDs because 

not all LED applications or phosphor combinations were 

considered. Compositions may differ significantly if different 

phosphors from those selected are used. Because a growing number of LEDs are being custom manufactured to meet 

customer specifications, reliable data on the exact composition 

of LEDs and their phosphors, such as REE variety and weight 

percentages, are difficult to acquire, can differ by manufacturer, and are considered proprietary information (U.S. 

Department of Energy, 2010c). Because an examination of 

the great variety of LEDs commercially available was beyond 

the scope of this study, estimates were developed for a limited 

number of LED applications using a limited set of LED and 

phosphor types to provide a perspective of the industry for the 

most common applications. Table 2 is not intended to cover 

the material requirements for all LED applications. Estimates 

should be considered to be a snapshot because LED technolTable 1. Selected sources of lighting for light bulbs producing a similar light intensity measured in lumens.

Light source Light bulb lifetime,

in hours

Cost of ownership1 Efficiency, in 

percent

Efficacy, in

lumens per watt 1 year 5 years

60-watt incandescent light bulb 1,000 $18 $90 5 15

Warm compact fluorescent lamp (CFL) 13,600 $6 $28 20 60

60 lumens per watt warm white light-emitting diode (LED) 50,000 $18 $36 30 100

1

Calculated based on the cost of purchasing specified light bulbs over the specified timeframe, costs for operating said light bulbs for 8 hours per day, and 

maintenance costs associated with the device. An electricity cost of $0.10 per kilowatthour was assumed. The assumed cost of an incandescent bulb is $0.50, of 

a CFL bulb is $2.00, and of an LED bulb is $14.00. Data are from Humphreys (2008).
Byproduct Material Requirements for Selected Light-Emitting Diode Markets 11

Table 2. Material requirements of selected metals for selected light-emitting diode markets for 2010 and 2014.

[Does not cover the material requirements for all light-emitting diode (LED) applications, so should be considered as minimum approximations of selected material requirements. Many other small applications not included could increase LED material estimates. Estimates should be considered a series of two snapshots 

because LED technology is constantly changing, as are the amounts and types of constituent materials. Actual material requirements could differ significantly 

from these estimates because LEDs are not generic and do not have the standardized composition used in these estimates. Values are included for the LED chip 

and the phosphor, where appropriate, but do not include materials external to the chip such as the light assembly or LED drivers. Market data are from McKinsey & Company, Inc. (2011), and LED composition data are from Lim and others (2010). Data may not add to totals shown because of rounding. As, arsenic; Ce, 

cerium; Eu, europium; Ga, gallium; Gd, gadolinium; In, indium; La, lanthanum; Tb, terbium; Y, yttrium; e, estimated; —, negligible]

Application

LEDs producede Materials used in LEDs, in kilograms

Units, in 

millions

Percentage of 

total As Ce Eu Ga Gd In La Tb Y

2010

Signage 13,000 22 480 — — 360 — 7 — — —

Traffic signals 2,900 5 28 43 9 25 33 1 34 12 100

General lighting 7,700 13 — 390 6 9 500 6 — — 160

Automotive 770 1 12 32 11 19 17 1 18 7 230

Televisions 6,000 10 1 32 28 9 — — — — 650

Computer monitors 1,400 3 1 8 7 4 — 1 — — 160

Laptop computers 4,900 8 1 26 22 13 — 1 — — 530

Handheld electronic devices 22,000 37 120 170 42 130 — 4 180 63 2,100

Total 59,000 100 640 700 130 570 550 21 230 82 3,900

2014

Signage 18,000 12 660 — — 500 — 9 — — —

Traffic signals 6,000 4 110 170 36 100 130 1 140 49 410

General lighting 65,000 42 — 3,300 50 78 4,200 52 — — 1,300

Automotive 2,300 2 52 130 72 62 43 15 45 16 1,600

Televisions 28,000 18 1 150 130 44 — — — — 3,000

Computer monitors 16,000 10 1 77 67 30 — 2 — — 1,600

Laptop computers 14,000 8 1 75 65 30 — 2 — — 1,500

Handheld electronic devices 22,000 5 120 170 41 130 — 4 170 62 2,100

Total 170,000 100 940 4,100 460 980 4,400 85 350 130 12,000

ogy is constantly changing, as are the amounts and types of 

constituent materials. Actual material requirements could 

differ significantly from the estimates because LED types in 

use are not generic and do not have the standardized composition used in these estimates. In addition, table 2 does not show 

the material requirements for LEDs beyond 2014 when LED 

consumption is expected to increase in most existing applications and to be used in new applications in the automotive and 

general lighting sectors.

Although the data listed in table 2 are not all inclusive, 

some inferences may be drawn from these estimates. First, the 

consumption of the nine materials selected for analysis in LED 

applications is very small given the billions of LEDs that are 

manufactured. The estimated 59 billion LEDs consumed in 

2010 would require only about 3.9 t of yttrium, 0.7 t of cerium, 

0.6 t each of arsenic, gallium, and gadolinium, and smaller 

amounts of the rare earths europium, indium, lanthanum, and 

terbium. Based on estimates of the projected growth of the 

industry, the 170 billion LED consumption in 2014 would 

require approximately 12 t of yttrium, 4.4 t of gadolinium, 

4.1 t of cerium, 1 t of gallium, and less than 1 t of all the other 

materials listed in table 2. Applications that use white LEDs 

require very little arsenic, while applications that use red LEDs 

tend to require more arsenic. Most of the gallium used in LEDs 

is for signage and handheld electronic devices. The greatest 

amount of cerium used in LEDs is for general lighting applications. Yttrium used in LEDs is primarily intended for backlit 

televisions and handheld devices. As demand of LEDs for these 

sectors changes and newer LEDs and phosphors with different 

compositions are developed, it is likely that the distribution and 

quantity of these materials will change as well.

Even though billions of LEDs are produced each year, 

study data indicate that the total material requirement in 2010 

for eight of the nine materials assessed in this study was less 
12 Byproduct Metals and Rare-Earth Elements Used in the Production of Light-Emitting Diodes

than 1 t for each commodity. The study showed that about 3.9 

t of yttrium was consumed in the LED markets assessed in 

this evaluation. The amount of total REEs required for LED 

phosphors is small when compared with the amounts of REEs 

required for phosphors that are used in CFLs and other lighting types, and the distribution of rare earths in LEDs is different than the distribution of rare earths in CFLs and fluorescent 

lighting. These results are consistent with the estimates of 

Byron Capital Markets, which suggest that growth of the LED 

industry would have little effect on demand for rare earths 

(Hykawy and others, 2010). Consequently, data suggest that 

the available supply of these byproduct materials, including 

rare earths, should be able to meet the growing demand of the 

LED industry, at least for the next 5 years.

The latest (December 2011) survey of critical materials 

conducted by the U.S. Department of Energy forecasts that 

LED technology used in general lighting will not begin to 

significantly affect global REE demand until about 2017 (U.S. 

Department of Energy, 2011c). The consumption of materials 

used in LEDs consumed by the lighting sector (particularly 

cerium, europium, gadolinium, lanthanum, terbium, and 

yttrium) will likely increase after 2017.

Any LED supply shortages over the next 5 years would 

most likely be the result of a short-term lack of manufacturing and processing capacity or changes in supply of Chinese 

raw materials or manufactured products as a result of export 

restrictions. For 2010, China’s export quota for rare earths was 

22,512 t of REO-equivalent from domestic producers and traders and 7,746 t from Sino-foreign joint ventures (Tse, 2011). 

This represents about half the level of exports of rare earths 

allowed in 2000. End-use applications such as LED wafers that 

are produced outside of China and rely heavily on Chinese raw 

materials of rare earths are affected most by these quotas. However, end-use markets that use Chinese REEs but manufacture 

the finished product in China (such as many phosphor powders) 

are not affected by the Chinese restrictions, although they may 

be affected by tariffs imposed by some importing countries.

Summary

The light-emitting diode (LED) industry is expanding 

because various governments have been phasing out the use 

of traditional incandescent lighting in favor of more efficient 

lighting systems, increased monitoring of fluorescent lighting, 

technological improvements, and decreased cost. The longer 

life and reduced power consumption of some LEDs have led 

to annual energy savings, reduced maintenance costs, and 

lower emissions of carbon dioxide, sulfur dioxide, and nitrogen oxides from powerplants because of the resulting decrease 

in energy consumption required for lighting applications when 

LEDs are used to replace less-energy-efficient sources. Metals 

such as arsenic, gallium, indium, and the rare-earth elements 

(REEs) cerium, europium, gadolinium, lanthanum, terbium, 

and yttrium are important mineral materials used in LED 

semiconductor technology. Most of the world’s supply of these 

materials is produced as byproducts from the production of 

aluminum, copper, lead, and zinc. The rare earths required for 

LED production come from China, and most LED production 

facilities are in Asia.

The LED manufacturing process is complex and is undergoing much change with the growth of the industry and the 

changes in demand patterns of associated commodities. In many 

respects, the continued growth of the LED industry, particularly 

in the general lighting sector, is tied to its ability to increase 

LED efficiency and color uniformity while decreasing the costs 

of producing, purchasing, and operating LEDs. Research is supported by governments of China, the European Union, Japan, 

the Republic of Korea, and the United States. Because of the 

volume of ongoing research in this sector, it is likely that the 

material requirements of future LEDs may be quite different 

than those of LEDs currently (2011) in use with attempts by the 

industry to reduce costs by reducing material requirements of 

expensive heavy rare-earth phosphors and increasing the sizes 

of wafers for economies of scale. Improved LED performance 

will allow customers to reduce the number of LEDs in automotive, electronic, and lighting applications, which could reduce 

the overall demand for material components.

Other than perhaps short-term interruptions resulting 

from market forces and (or) geopolitical events, significant 

long-term material constraints that would impede consumption 

of LEDs as a replacement for traditional incandescent lighting 

are not anticipated. Because arsenic concentration in LEDs is 

reportedly lower than what is required by Federal and State 

guidelines, arsenic in LEDs does not pose a safety hazard, 

and the small amount of arsenic required for LED production 

is not anticipated to lead to supply disruption unless regulations governing arsenic production and processing facilities in 

China and other producing countries are tightened, delaying 

production or increasing the cost of arsenic enough to impair 

the production of LEDs. An increase in gallium demand 

beyond current (2011) capacity can be satisfied by expansion 

of recovery circuits at existing alumina facilities or increased 

recycling of gallium arsenide wafers. The supply of indium 

is anticipated to be able to meet growing industrial demand 

because exploration of deposits containing high amounts 

of indium has become more attractive and supply is being 

increased by adding or expanding additional recovery circuits. 

Recovery of indium from tailings and slags and research on 

the recycling of indium from flat-panel liquid crystal display 

or LED-backlit televisions are showing promise. Non-Chinese 

sources for rare earths are being developed and are likely to 

be in operation in time to meet increasing demand for rare 

earths from the LED sector. Because most LED component 

production and manufacturing occurs in Asia and many LED 

producers have established supply contracts with Chinese 

producers of rare earths, a significant amount of the metallic 

gallium, indium, and the rare earths used for LED production 

will likely continue to come from Chinese sources at least for 

the next 5 years; however, a greater amount of these materials are now being processed in Japan, the Republic of Korea, 
Selected References 13

and Taiwan. As non-Chinese sources of rare earths come into 

production, these new mines are likely to be sources of light 

REEs, but China will likely remain the leading source of 

supply for the heavy REEs suitable for use as LED dopants 

and phosphors for the next few years. Increased research in 

the development of phosphors that use smaller amounts of 

or different REEs is intended to reduce dependence on rare 

earths from China. Supply disruption or rare earths and other 

specialty metals could take place if China’s specialty metal 

exports are redirected to domestic markets.

Because the cost of recovery is high, the lifespan for 

LEDs is comparatively long; thus, the LED waste volume was 

low in 2010, and few LEDs were recycled. The minute metal 

content of LEDs leads to a high cost for recovery, so recycling 

of LEDs outside of electronic waste is unlikely in the near 

term, although some LED producers are evaluating recycling 

options. Recycling of metals from LEDs in electronic waste 

is possible if the costs of recovering metals are justified by 

demand and metal prices.

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