# Presentation: 788612

## Charles M. Lieber, Harvard University

***Charles M. Lieber, Harvard University***

***Nanowires, Nanoscience & Emerging Technologies***

**http://cmliris.harvard.edu**

## Uniqueness Nanotechnology: Bottom-Up Paradigm

**Proteins**
**DNA**
**Phospholipids**

***Limited set of building blocks organized and differentiated to yield complex living organisms OR integrated systems.***
***Encode function during synthesis (not all lithography)***
***3D functional structures***

## Outline of Presentation

***Building Blocks ***
***Properties of Nanodevices***
***Assembly of Integrated Structures***
***A Look at Application Areas***
***bio-nanoelectronic devices***
***renewable energy***
***3D integrated circuits***
***Critical Needs for Future***

## Molecular Scale Nanowires

- Diameter controlled during growth by nanocluster  catalysts.
- Uniform single crystal structures for diameters as small as 2-3 nm.
- Electronic characteristics controlled reproducibly!

**Molecular Scale Nanowires**

- Morales & Lieber, *Science* **279**, 208 (1998)
- Cui*, *Lieber & coworkers, *Appl. Phys. Lett. ***78**, 2214* *(2001)
- Wu, Lieber & coworkers, *Nano Lett.* **4**, 433 (2004)

## Building Blocks with  Controllable Complexity

***Growth of nanowires with well-defined structural and composition complexity yield diverse and controlled function!***

- Morales & Lieber, *Science* **279**, 208 (1998)

- Gudiksen, Lauhon, Wang, Smith & Lieber, *Nature* **415**, 617 (2002)

- Lauhon, Gudiksen, Wang & Lieber, *Nature ***420**, 57* (*2002)

- Wang & Lieber, *Nature Mater.* **2**, 355 (2003)
- Wang, Qian, Yang, Zhong & Lieber, *Nano Lett*. **4**, 871 (2004)

**Notes:**
Can Capitalize on Natural Properties of Materials and Ease of Manufacting. Combinatorics!
-Bandgaps
-Instrinsic Carrier Nature.

Cant’t do this conventional silicon process.  - Can’t do Combinatorics.

## Core/Shell Nanowire Heterostructures

**Core/Shell Nanowire Heterostructures**

***Core/shell nanowires enable studies of electron and hole gases confined in uniform 1D potential.***
***Reduced scattering expected to translate into higher mobility/performance FETs and other unique devices & physics!***

- Lu, Xiang, Timko, Wu & Lieber, *PNAS ***102**, 10046 (2005)

## Germanium/Silicon Core/Shell Nanostructures

- Device yield ca. 100%
- Accumulation of holes in absence of applied gate
- T-dependence shows no accoustic phonon scattering, and suggests possible room-T ballistic transport.
**Unique system for low-T quantum transport and RT high performance electronics.**

- Lu, Xiang, Timko, Wu & Lieber, *PNAS ***102**, 10046 (2005)

## Pushing Nanowire FET Limits: Ge/Si Core/Shell Structures

**Transconductance** = 26 S (VSD= -1V)
**Max I****on**= 35 A
**Scaled values (V****dd****=1V; 70/30 on/off)**:
- 	Gm = 1.4 mS/m
- 	Ion = 0.78 mA/m
**S = 105 mV/decade**

- Xiang, Lu, & Lieber, *Nature ***441**, 489 (2006)

## Scaled Ge/Si Nanowire FETs

- L= 40 nm, **8x **faster than Si p-MOSFET, and shows fundamental limit > 2 THz
- At low bias (Vds ≤ -0.1V), Ion is ~100% of the ballistic limit
- At high bias, ~ 80% of the ballistic limit achieved without correction, and suggests inelastic scattering has small effect in these quasi-1D NW devices.
** ****First direct evidence of performance advantage in NWFET!**

**Scaled Ge/Si Nanowire FETs**

- Yongjie Hu, Xiang & Lieber

- Xiang, Lu, & Lieber, *Nature ***441**, 489 (2006)

## Double Quantum Dot with Integrated Charge Sensor Based on Ge/Si Nanowires

- Full control of interdot coupling and barrier height by local top gates
- Plunger gates control charge number
- Double dot capacitively coupled to adjacent sensor nanowire QD
- Charge sensing critical for single-electron double dots and spin control

**Double Quantum Dot with Integrated Charge Sensor Based on Ge/Si Nanowires**

- Marcus & Lieber

## Assembling Integrated Systems

**Assembling Integrated Systems**

**pattern**

**Langmuir-Blodgett Assembly**

**Contact Printing**

**Blown Bubble Films**

***Combine optimized n- and p-channel materials at will!***
***Parallel and scalable assembly with defined orientation and controlled spacing***
***Parallel and scalable interconnection of nanowires and devices***

- Jin, Whang, Lieber & coworkers, *Nano Lett.* **4**, 915 (2004)

- Javey, Nam, Lieber & coworkers, *Nano Lett.* **7**, 773 (2007)** **

- Yu, Cao & Lieber, *Nature Nanotech.* **2**, 372 (2007).** **

**Notes:**
What are key requirements to implement bottom-up paradigm; key issues to address in talk and in general (make list of questions)
 review nanowires in couple of slides--properties and what can control; review FETs, including cNW devices; also nonvolatile switches (w/molecular analogies?)
Architectures: Slide show/outlining nano-CMOS hybrid and all nano, with some important advantages/disadvantages of each
Hierarchical Assembly
Described fluid/field/LB and +/-
Describe at least NOR logic structures and prospects
Ongoing stuff: LB; superlattice– note reasons
Key approaches to making contacts– from bottom or from top???
Summary

## Patterned Organization By Direct Printing

- Javey, Nam, Lieber & coworkers, *Nano Lett.*** 7**,** **773 (2007)

- Specific array structure defined by conventional lithography prior to assembly  **can exploit existing industry capabilities!**
- Printing yields controlled density and well-aligned nanowires
- Applicable to wafer scale processing
- Multi-step printing of distinct nanowire types in-plane and for multilayer structures

## Large Area Blown Bubble Films of Aligned Nanoscale Wires

- Yu, Cao & Lieber, *Nature Nanotech.* **2**, 372 (2007).** **

## Geometric Scaling of 3D Structures 

**Geometric Scaling of 3D Structures**** **

## Nanoelectronics-Biology Interface

**Nanoelectronics-Biology Interface**

- Cui, Wei, Park & Lieber: *Science* **293**,1289 (2001)
- Patolsky & Lieber: *Materials Today* **April**, p.20 (2005)

## Multiplexed Detection with Nanowire Arrays

- NW 1-3: w/ PSA antibody
- NW 4-5: w/ CT antibody
- NW 6-7: w/ BT antibody
- NW 8-11: w/ ethanolamine only

**Injections:**
- (a) 5 ng/ml PSA
- (b) 5 ng/ml Cholera toxin (CT) subunit-B
- (c) 5 ng/ml Botulinum toxin (BT)
- (d) 10 g/ml HSA
- (e) 5 ng/ml PSA + 5 ng/ml CT + 5 ng/ml BT
- (f) Solution (5) pre-mixed w/ all three antibodies 10 g/ml

**Multiplexed Detection with Nanowire Arrays**

- Zheng, Patolsky & Lieber

## Single-Particle Detection: How Small?

**Can the sensitivity of nanowire sensors be pushed to enable true single molecule detection?**
**Consider the case of small oligonucleotides:**

**Ying Fang**, Zheng, & Lieber

## Electrical Detection of Single Oligonucleotides

**PNA Receptor: ATCATCTTTG **
**DNA Target:          GTAGAAACTA**

**Fang,** Lieber & coworkers, *submitted*

*********Q of 10-charges detected with excellent S/N***

## Vision for Nanowire Sensor Arrays

**Vision for Nanowire Sensor Arrays**

-    sensor array

**Future is Bright!**
**serum proteins & disease marker proteins**
**viruses and pathogens**
**genomic DNA analysis**
- small molecule-protein screening for drug discovery
- detection & kinetics platform
- electronic single-molecule detection/biophysics
- and much more.....................

## Nanoelectronic-neuron interfaces: Future opportunities for medical devices and hybrid information processing systems

**Input/output of electrical signals?**
**Input/output of chemical signals?**

## Multiplexing: Inputs and Outputs

- NW1

- NW2

- NW3

- NW4

- axon

- IC

**IC Stimulation**

**NW1 Stimulation**

**Similar dendritic response for IC vs. NW stimulation.**
**NW interfaces are highly spatially selective.**
**Multiplexed scheme enables fully noninvasive, two-way communication.**

- Patolsky, Timko, Lieber & coworkers, *Science* **313**, 1100 (2006)

## Approaches to 3D Neural-Nanoelectronic Structures and More

**growth**

**Approaches to 3D Neural-Nanoelectronic Structures and More**

**Exploit unique capability of fabrication on flexible polymeric substrates (use systems w/known cell compatibility) **
**Create pathways in ‘planar’ substrate for axons/dendrites and other cells to ‘cross the plane’**
**Crumple, scroll or fold, and then grow cells to form quasi-3D network**

**crumple**
**scroll**

**Very Smart Tissue**
**Artificial Brain?**

## Nanowire Solar Cells/Power Sources

- Tian, Zheng, Kempa & Lieber, *submitted*

***p*****-type/intrinsic/*****n*****-type (*****p*****-*****i*****-*****n*****) core/shell/shell silicon nanowires in which the structure and composition of the core and shells are readily controlled. **
**Radial structures might enable improved carrier collection and overall efficiency, comparable to single crystal semiconductors, while retaining solution processing of nanoparticle and organic systems.**

## p-i-n Core/Shell Nanowire Properties

- Tian, Zheng, Kempa & Lieber, *submitted*

**Dark current-voltage (*****I-V*****) curves demonstrate that (i) ohmic contacts are made to both core and shell portions of the NWs, (ii) good rectifying/diode behavior with (iii) diode quality factors, n, of ~2.**

## Assembly of Multi-Functional Structures: NW-Photovoltaic Powered Nanodevices

- Tian, Zheng, Kempa & Lieber, *submitted*

## 3D Integration of Nanowires

- Device/Circuit
- Fabrication

- Insulation Layer
- Deposition

- Assembly or Printing of Nanowires

**3D Integration of Nanowires**

- Javey, Nam, Lieber & coworkers, *Nano Lett.*** 7**, 773 (2007)

## 3D Assembly of Multi-Nanowire FETs

- 10 independent layers of Ge/Si NW FETs fabricated
- Measurements demonsrate consistent layer-to-layer performance

**3D Assembly of Multi-Nanowire FETs**

- Javey, Nam, Lieber & coworkers, *Nano Lett.*** 7**, 773 (2007)

## 3D CMOS Circuits: FETs and Inverters

**3D CMOS Circuits: FETs and Inverters**

- S. Nam, D. Ham & C. Lieber

**Ge/Si**

**InAs/InP**

## 3D CMOS Circuits: Ring Oscillators

- S. Nam, D. Ham & C. Lieber

## Multi-functional 3D Electronics

**3D Electronics. **Bottom-up approach opens up opportunity for facile assembly of multiple functional layers and new architectural concepts.
- Layers can be integrated with existing CMOS chips/function in hybrid structures or used to build stand-alone electronics.

## Future Challenges: Role for NSLS-II

- Fundamental advances in nanoscience of building blocks, devices and their hierarchically-organized structures that will drive emerging and future technologies requires detailed characterization of structural and electronic properties on multiple length scales and environments.
**Light sources with the advanced capabilities proposed for NSLS-II will help to drive this science and technology revolution, and can help to ensure American competitiveness for many years into the future!**

**Future Challenges: Role for NSLS-II**