Search query: Carrier concentration CuInSe2

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abstract: The I III VI 2 group semiconductors are of great importance due to their applications in solar cell fabrication. Spray pyrolysis is a very cheap and inexpensive method of depositing thin films of large area. We have deposited CuInSe 2(1 x) S 2x on glass substrate at 350 0 C by varying the proportion parameter x by this method. Resistivity, Hall coefficient and carrier concentration were measured at room temperature by Van der Pauw Hall method. From these results we conclude that resistivity and Hall coefficient increases as composition parameter x increases. While Hall mobility and carrier concentration decreases as x increases.The resistivity, Hall coefficient and carrier concentration fallow the parabolic variation.
author_names: Yashwantrao D Tembhurkar
title: Resistivity, Hall Coefficient and Carrier Concentration of Cuinse2(1 X)S2x Thin Films by Spray Pyrolysis
year: 2017

abstract: Copper indium selenide CuInSe2(CISe) thin films were deposited by chemical spray pyrolysis (CSP) method of CuInS2(CIS) and subsequent selenization process. To study the effects of solution concentration, we prepared different precursors solution of CIS including different amount of indium salts from 0.025 to 0.100 M with In/Cu 1.25 and S/In 4. These results propose that solution concentration is critical for inflecting the morphological, optical, electrical, and electrochemical characteristics of solution processed CISe films and device performance. The studied morphological properties of deposited samples were homogenous, crack free with large grains in indium salt concentrations more than 0.075 M. The deposited film thickness depends on the spray precursor concentration and increases for higher concentration. In addition with increasing of indium precursor concentration from 0.025 to 0.100 M in spray solution, the optical bandgap of deposited film decreases from 1.40 to 1.35 eV. Also the films mobility and carrier density were notably influenced by any change in the solution concentration. Electrical and electrochemical properties showed a decrease in carrier density from 1020 to 1017 cm 3 and the increase in mobility of order 10 7 to 10 2 cm2/V s, respectively, for 0.025 M, 0.100 M CISe films. All films exhibited p type conductivity owing to different concentrations. However, it seems that the concentration of the ideal solution is 0.100 molars.
author_names: Maryam Hashemi

Seyed Mohammad Bagher Ghorashi

Fariba Tajabadi

Nima Taghavinia
title: Investigation of precursors concentration in spray solution on the optoelectronic properties of CuInSe2 thin films deposited by spray pyrolysis method
venue: Journal of Materials Science: Materials in Electronics
year: 2020

abstract: Cu2SnSe3 based compounds with a diamond like structure are promising thermoelectric materials. However, the relatively high lattice thermal conductivity limits further improvement in their thermoelectric performance. In this work, two compounds including In2Se3 and CuInSe2 are employed to alloy with Cu2SnSe3 aiming to decrease lattice thermal conductivity and their corresponding effects are compared. It is found that alloying with CuInSe2 is more beneficial to reduce lattice thermal conductivity and maintain the power factor, as evidenced by a higher quality factor B. Subsequently, both In and Ga doping is performed to regulate the carrier concentration of (Cu2SnSe3)0.80(CuInSe2)0.2. Finally, (Cu2Sn0.97Ga0.03Se3)0.80(CuInSe2)0.20 displays a decent zT of ~0.98 at 823 K, a nearly six fold higher value compared to that of the pristine sample. Additionally, a zTave of ~0.35 over 300 823 K is obtained in (Cu2Sn0.97Ga0.03Se3)0.80(CuInSe2)0.20, which is among the best reported p type Cu2SnSe3 based compounds. The result proves that alloying with CuInSe2 combined with carrier concentration optimization is a valid strategy to improve the thermoelectric performance of Cu2SnSe3 based compounds.
author_names: Guoyu Wang

Xiao Zhang

Yuling Huang

Xiaoyuan Zhou
title: Synergistic effect of CuInSe2 alloying on enhancing the thermoelectric performance of Cu2SnSe3 compounds
year: 2020

abstract: Abstract The absorption spectra of as grown and copper annealed n CuInSe 2 samples were obtained at room temperature. A shift of the absorption edge to higher energy for the annealed sample as compared to its value in the as grown sample, is observed in the measurements. This behaviour can be explained as due to the fact that n CuInSe 2 becomes degenerate at relatively low electron concentration because of its small electron effective mass.
author_names: Carlos Rincon

Gerardo Sanchez Perez
title: Influence of the carrier concentration on the optical absorption edge of n CuInSe2
year: 1984

abstract: Silver alloying and KF post deposition treatments are explored as approaches to increase the efficiency of low bandgap CuInSe<sub>2</sub> (CIS) solar cells. The KF treatment prevents a loss in <italic>V</italic><sub>OC</sub> when CIS has a thinner CdS layer, and also increases the carrier concentration of these devices. Compared with CIS devices, Ag alloyed CIS (ACIS) devices have lower efficiencies due to a lower carrier concentration which decreases <italic>V</italic><sub>OC</sub> When ACIS is exposed to the KF treatment, the resulting devices have reduced <italic>V</italic><sub>OC</sub> and fill factor <italic>FF</italic> compared with untreated devices; however, thinning the CdS layer with KF treated ACIS improves <italic>V</italic><sub>OC</sub> ACIS+KF films show an unidentified compound in Raman spectra and the resulting solar cells have a dominant interface recombination mechanism and light to dark crossover. An electron microscopy study of the growth and coverage of CdS reveals that KF treated samples in this study have faster CdS growth and ACIS+KF has complete CdS coverage with less than half of the normal deposition time. Improved coverage of CdS layers on KF treated samples is also verified by X ray photoelectron spectroscopy. Finally, using a heat treatment and an anti reflection layer enables CIS+KF solar cells to obtain a high 16.0% efficiency for CIS with a <italic>V</italic><sub>OC</sub> 526 mV and <italic>J</italic><sub>SC</sub> 41.0 mA/cm<sup>2</sup>
author_names: Nicholas H Valdes

Jinwoo Lee

William N Shafarman
title: Ag Alloying and KF Treatment Effects on Low Bandgap CuInSe2 Solar Cells
venue: IEEE Journal of Photovoltaics
year: 2019

author_names: R Pal

Kalyan Kumar Chattopadhyay

Subhadra Chaudhuri

Arun Kumar Pal
title: Dependence of electrical conductivity, carrier concentration, band gap and grain size of CuInSe2 films on the composition
year: 1993

abstract: Chalcopyrite structured semiconductor CuInSe2 has received considerable attention owing to its promising electrical and optical properties for nonlinear optical instruments and photovoltaic solar cells. In view of these interesting properties of CuInSe2, it is thought to be worthwhile to study the high pressure electrical transport behavior of this compound. Herein, we use in situ Hall effect measurements, temperature dependent electrical resistivity measurements, and first principles calculations to conduct a comprehensive study on the carrier behavior and the band structure of CuInSe2 under high pressure. The resistivity shows an obvious increase with pressure and reaches the maximum value at 7.2 GPa, indicating that pressure enlarges the band gap which has been confirmed by the result of the subsequent band structure calculations. Dramatic changes in electrical transport parameters, such as Hall coefficient, Hall mobility, carrier concentration, and electrical resistivity, are detected at 7.2 GPa, whic.
author_names: Meiyan Ye

Ruilian Tang

Shuailing Ma

Qiang Tao

Xuefeng Wang

Yuanjie Li

Pinwen Zhu
title: Electrical Transport Properties and Band Structure of CuInSe2 under High Pressure
venue: The Journal of Physical Chemistry C
year: 2019

abstract: Abstract Na has been believed to improve the device parameters of open circuit voltage (VOC) and fill factor (FF) presumably by increasing the carrier concentration (NA) of vacuum processed Cu(In,Ga)Se2 films. In solution processed CI(G)Se devices as well, Na reportedly increases VOC and FF but this improvement is not correlated with the increase in NA, suggesting a different physical mechanism associated with Na in solution based routes. In this contribution, experimental results on the role of Na addition in solution processed CISe films and devices were reported, in which Na addition had no influence on NA nor on film composition in spite of the notable increase in the device efficiency. On the contrary, Na was found to mitigate the interfacial recombination by reducing the undesirable surface defects. Along with this understanding, Na addition in our air processable route resulted in a CISe device with 12.83% efficiency, which is comparable to the current world record efficiency of solution processed CISe devices.
author_names: Shanza Rehan

Jihyun Moon

Tae Gun Kim

Jihye Gwak

Juran Kim

Jeong Won Kim

William Jo

Seung Kyu Ahn

Sejin Ahn
title: Role of Na in solution processed CuInSe2 (CISe) devices: A different story for improving efficiency
year: 2018

abstract: In this study CuInSe2 and CuInS2 thin films were prepared onto ITO glass substrate using the electrodeposition technique in aqueous solution. The electrodeposited films were characterized by X ray diffraction (XRD) scanning electron microscopy (SEM) and energy dispersive X ray analysis. The annealing effects on electrodeposited precursors were investigated. The chalcopyrite structure of CuInSe2/CuInS2 showed an enhancement of crystallinity after subsequent selenization/sulfurization treatment in Se/S atmosphere, respectively. XRD and SEM studies revealed a dramatic improvement of the crystalline quality of CIS films after annealing treatments. Mott Schottky measurements were used to assess the conductivity type of the films and their carrier concentration. The prepared samples underwent an etching process to remove the binary accumulated Cu2 x(Se,S) phases shown in FESEM pictures. This etching process has shown a noticeable decrease in both, the flat band potential, Vfb (V) and the number of acceptors, NA (cm 3) in selenized CuInSe2 and sulfurized CuInS2 samples.
author_names: Suzan Saber

M Mollar

Amany M El Nahrawy

Nagwa Mohamed Aly Khattab

A H Eid

Mohamed Mahmoud Abo-Aly

B Mari
title: Annealing study of electrodeposited CuInSe2 and CuInS2 thin films
year: 2018

abstract: We investigate the dopant concentration and majority carrier mobility in epitaxial CuInSe2thin films for different copper to indium ratios and selenium excess during growth. We find that all copper poor samples are n type, and that hopping conduction in a shallow donor state plays a significant role for carrier transport. Annealing in sodium ambient enhances gallium in diffusion from the substrate wafer and changes the net doping of the previously n type samples to p type. We suggest that sodium incorporation from the glass might be responsible for the observed p type doping in polycrystalline Cu poor CuInSe2 solar cell absorbers.
author_names: Florian Werner

Diego Colombara

Michele Melchiorre

Nathalie Valle

Brahime El Adib

Conrad Spindler

Susanne Siebentritt
title: Doping mechanism in pure CuInSe2
year: 2016