Search query: Absorption coefficient of CuInSe2

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abstract: Abstract In this paper we describe a new photoacoustic cell design that allows simultaneous photoacoustic and photoconductive measurements of solid semiconductor samples. The two techniques are complementary. Photoacoustic spectroscopy is known for being a direct monitor of nonradiative de excitation processes, while photoconductivity spectroscopy is a direct monitor on the photocurrent generated following the absorption of the radiation source. If used simultaneously, they should unveil valuable information on the properties of materials. As an application to the refined spectrometer we present a comparative study on the optical absorption properties of CuInSe2 single. The measurements were performed at room temperature close to the absorption edge. Appropriate theoretical models have been used to evaluate the absorption coefficient spectral dependence from measured data. The combined techniques showed varying sensitivities in detecting defects levels in different regions of the absorption spectrum of the compound, and thus offering more information on the defects structure of semiconductors in a quicker way.
author_names: Fatima Zohra Satour

Ameur Zegadi
title: An optical absorption properties investigation of CuInSe2 by a simultaneous photoacoustic photoconductivity measuring technique
year: 2020

abstract: CuInSe 2 (CIS) and Cu(In,Ga)Se 2 (CIGS) semiconductors are the most studied absorber materials for thin films solar cells due to their direct bandgap and large absorption coefficient. The highly efficient CIGS devices are often fabricated using expensive vacuum based technologies; however, recently electrodeposition has been demonstrated to produce CIGS devices with high efficiencies and it is easily amenable for large area films of high quality with effective material use and high deposition rate. In this context, this chapter discusses the recent developments in CIS and CIGS technologies using electrodeposition. In addition, the fundamental features of electrodeposition such as direct current, pulse and pulse reverse plating and their application in the fabrication of CIS and CIGS films are discussed. In conclusion, the chapter summarizes the utilization of pulse electrodeposition for fabrication of CIS and CIGS films while making a recommendation for exploring the group's unique pulse electroplating method.
author_names: Sreekanth Mandati

Bulusu V Sarada

Suhash Ranjan Dey

Shrikant V Joshi
title: Pulsed Electrochemical Deposition of CuInSe2 and Cu(In,Ga)Se2 Semiconductor Thin Films
year: 2018

abstract: CuInSe2 with chalcopyrite structure has become one of the most promising photoelectric materials for its high optical absorption coefficient and conversion efficiency. Electrodeposition has the advantages of low cost and easy operation. CuInSe2 thin films were prepared by one step electrodeposition with CuC12*2H2O, InC13, SeO2 as raw materials. Cyclic voltammetry curves of the solutions were tested by electrochemical workstation. The phases of product thin films were analyzed by X ray diffraction (XRD) and the surface morphology was characterized by scanning electron microscope (SEM) Experimental results show that the continuous, uniform and dense CuInSe2 thin films can be obtained under conditions of deposition potential 0.5 V and sodium citrate as complexing agent with concentration of 5mmol/L. The XRD diffraction peaks of CuInSe2 thin film are corresponding to the crystal planes of (112) (220) and (312) respectively.DOI: http:/dx.doi.org/10.5755/j01.ms.23.4.17447
author_names: Kegao Liu

Chaoya Xu

Hong Liu

Yong Hu

Lu Dan Shi
title: The Phase and Morphology of CuInSe2 Film Prepared by One Step electrodeposition
year: 2017

abstract: ABSTRACT CuInSe2 as one I III VI ternary compound with direct band gap, has become one of the most promising photovoltaic materials due to high optical absorption coefficient and conversion efficiency. CuInSe2 films were prepared by electrodeposition with CuCl2*2H2O, InCl3, SeO2 as raw materials. The phases of product films were analyzed by X ray diffraction (XRD) and the morphology was characterized by scanning electron microscope (SEM) Experimental results show that dense and continuous CuInSe2 films can be obtained under conditions of deposition potential 0.5 V, pH 2.5 and raw materials ratio 6: 8: 12: 50, and the XRD diffraction peaks of CuInSe2 film are corresponding to (111) (220) and (311) crystal planes respectively, it consists of many rods with about 1 mm length; While the CuInSe2 film obtained under conditions of deposition potential 0.5 V, pH 2.0, and CuCl2*2H2O, InCl3, SeO2 and C6H5Na3O7*2H2O with concentrations of 6 mmol/L, 8 mmol/L, 6 mmol/L, 5 mmol/L respectively, shows different XRD diffraction peaks corresponding to (112) (220) and (312) crystal planes respectively, it consists of many non uniform particles with diameters about 0.5 1.5 mm distribute on the film surface with dense, continuous and unsmooth morphology.
author_names: Kegao Liu

Hui Liu

Jing Li

Yong Xu
title: The phases and morphology of CuInSe2 films prepared by different electrical deposition technologies
year: 2016

abstract: Monolayer MoS2, a direct bandgap transition metal dichalcogenide (TMD) has attracted worldwide attention in electronics and optoelectronics. However, the performance of photodetectors based on monolayer MoS2 is restricted to a weak optical absorption, narrow absorption range, and persistent photoconductance. Herein, benefiting from an easy solution process, high light absorption coefficient, and wide absorption range, environment friendly CuInSe2 quantum dots (QDs) are hybridized with monolayer MoS2 for high performance broadband photodetectors. Owing to the favorable type II energy band alignment of MoS2/CuInSe2 QDs, the hybrid photodetector exhibits a broadband photoresponse from the ultraviolet to near infrared region, with an ultrahigh photoresponsivity of 74.8 A/W at 1064 nm, and compared with those of the pristine MoS2 device, the photoresponsivity and specific detectivity in the ultraviolet visible region were enhanced by about 30 and 20 times, respectively. Furthermore, the formed depletion region at the MoS2/CuInSe2 QDs interface can significantly increase the photoresponse speed, and the accumulated holes in the QD side induce a strong photogating effect to improve the photoresponsive characteristics of the hybrid photodetector. Our work opens up opportunities for fabricating high performance monolayer TMD based broadband photodetectors.
author_names: Tao Shen

Feng Li

Zhenyun Zhang

Lei Xu

Junjie Qi
title: High Performance Broadband Photodetector Based on Monolayer MoS2 Hybridized with Environment Friendly CuInSe2 Quantum Dots.
venue: ACS applied materials interfaces
year: 2020

abstract: Measurements of optical absorption coefficient (a) were made on Bridgman grown CuInSe2 samples, over the wavelength range 1300 to 1600 nm, at room temperature. The samples were obtained from multi crystalline ingots, grown from melts of composition CuInSe2+x, plus y atomic of elemental sodium. Here, x, the excess of Se over stoichiometry, ranged from 0 to 0.4 and y, the percentage of Na in the melt, ranged from 0 to 11 at It was found that a was considerably increased by the original Na in the melt and also by a stoichiometric deficiency of Se in the melt; that is with a melt formula corresponding to CuInSe1.8, (or x 0.2) A smaller increase of a was observed with increase of x, the Se excess. With the addition of Na2Se in the melt, little change was obtained compared with the large increase with elemental Na.
author_names: An Qi Jin

Clifford H Champness

Hadley Franklin Myers

Ishiang Shih
title: Optical absorption measurements in the wavelength range 1.3 1.6 microns in Bridgman CuInSe2 grown from melts with added sodium
venue: 2013 IEEE 39th Photovoltaic Specialists Conference (PVSC)
year: 2013

abstract: Global energy crisis is one of the major concerns of the humankind due to the limited availability of fossil fuels which accomplish dominant portion of present days" energy. Hence, the need to develop renewable energy resources has come to the forefront of discussion. Solar photovoltaic is one of the major alternatives for future energy harvesting system; however, the utility of this emerging technology depends on the efficiency of the solar cell and viable techniques to commercialize it. Though silicon based photovoltaic technology is the most dominant till date but expensive manufacturing techniques pertaining to it is a major concern. In this context, chalcopyrite Cu(In,Ga)Se2 (CIGS) thin film technology has already witnessed high conversion efficiencies due to its suitable bandgap 1.20 eV) and large optical absorption coefficient 105 cm 1) The highly efficient CIGS devices are often fabricated using expensive vacuum based technologies; however, efforts to seek an economical and scalable method for the production of stoichiometric CIGS thinfilms have been ongoing to realize the commercialization of these devices. In pursuit of this, electrodeposition has been demonstrated to produce CIGS devices with high efficiencies and it is easily amenable for achieving large area films of high quality with efficient material utilization and high deposition rate. The use of multi steps, complexing agents, organic additives during the deposition using a three electrode system followed by a conventional selenization step have often been employed to achieve chalcopyrite compact CIGS which make the process more complex and expensive.
author_names: Sreekanth Mandati
title: Fabrication of CuInSe2 and Cu(In,Ga)Se2 Absorber Layersby Pulse and Pulse reverse Electrochemical Techniquesfor Solar Photovoltaic Applications
year: 2015

abstract: Highly ordered arrays of Cu rich and deficient CuInSe(2) nanotubes as well as ZnO/CuInSe(2) core/sheath nanocables have been synthesized on glass substrates by using ZnO nanorod arrays as sacrificial templates via a low cost solution method. Chemical conversions from hexagonal ZnO to cubic ZnSe, hexagonal CuSe and tetragonal CuInSe(2) are demonstrated as a novel means for synthesis of I III VI nanomaterials. Large differences in their solubility product constant (K(sp) are crucial for direct exchange in the conversions. In solvothermal reaction of ZnO/CuSe core/shell nanocables with InCl(3) the triethylene glycol solvent serves as a reducing agent for the reduction of cupric (Cu(2+ to cuprous (Cu( ions and also as an agent for the dissolution of ZnO cores. The absorption coefficient of the CuInSe(2) nanotubes in the visible region is on the order of 10(4) cm( 1) Photoelectrochemical solar cells were fabricated with arrays of ZnO/Cu(1.57+ 0.10)In(0.68+ 0.10)Se(2) and ZnO/CuSe nanocables. It was found that power conversion efficiency of the ZnO/Cu(1.57+ 0.10)In(0.68+ 0.10)Se(2) cell is about two times higher than that based on ZnO/CuSe.
author_names: Jun Xu

Chunyan Luan

Yong-Bing Tang

Xue Chen

Juan Antonio Zapien

Wen-Jun Zhang

H L Kwong

Xiang-min Meng

Shui-Tong Lee

Chun-Sing Lee
title: Low temperature synthesis of CuInSe2 nanotube array on conducting glass substrates for solar cell application.
venue: ACS nano
year: 2010

abstract: In this work, the electronic structure and dielectric function of chalcopyrite CuInSe2 are presented. The results are based on the full potential linearized augmented plane wave (FPLAPW) method using the generalized gradient approximation (GGA) plus an onsite Coulomb interaction U of the Cu d states. The dielectric constant, absorption coefficient and refractive index are explored by means of optical response. The spin orbit coupling effect is considered for the calculations of electronic structure and optical properties. We find that the results based on our calculation method have good agreement compared with experimental and other earlier simulations results.
author_names: Rong Chen

Clas Persson
title: Band Structure and Optical Properties of CuInSe2
year: 2014

abstract: Abstract CuInSe2 (CISe) colloidal quantum dots (QDs) display promising applications in photodetection especially within near infrared (NIR) regions due to their high extinction coefficient and environmental friendly. However, the high trap density and poor crystal quality introduced by the ternary structure result in low photodetection of CISe QDs devices. Herein, we dope transition metal manganese ions (Mn2+ into CISe QDs to tackle the above problems. Structural characterization results demonstrate the crystal quality of CISe QDs is improved by doping Mn2+ during the synthesis of QDs. The transient absorption (TA) spectroscopic study together with the space charge limited current (SCLC) measurements show the charge carrier lifetime of Mn CISe QDs is much longer than that of the CISe QDs, due to the Mn2+ doping state serve as hole capturer forming a charge compensated pair with the Cu2+ defect that makes the long lived Cu2+ radiative recombination dominate. Furthermore, Mn2+ doping concurrently modifies the conduction band minimum and valence band maximum level of the QDs verified by the ultraviolet photoelectron spectroscopy (UPS) which determines the driving force for charge carrier transfer to acceptors. The optimal Mn2+ doping level (0.01 Mn:Cu feed ratio) balanced the above two factors in the QDs. The detector based on such Mn CISe QDs exhibits responsivity of 30 mA/W and specific detectivity of 4.2 x 1012 Jones at near infrared wavelength, the response speed of 0.76 us, and suppressed dark current density of 1.6 x 10 10 A cm 2.
author_names: Ruiqi Guo

Jie Meng

Weihua Lin

Aqiang Liu

Tonu Pullerits

Kaibo Zheng

Jianjun Tian
title: Manganese doped eco friendly CuInSe2 colloidal quantum dots for boosting near infrared photodetection performance
year: 2021