{"title":"Performance optimization of single graded CIGS absorber and buffer layers for high efficiency: A numerical approach","authors":"R. Prasad, Rajarshi Pal, Udai P. Singh","doi":"10.1016/j.spmi.2021.107094","DOIUrl":null,"url":null,"abstract":"<div><p>We present a numerical simulation based study of single graded Cu(In,Ga)Se<sub>2</sub><span><span> (Copper Indium </span>Gallium<span><span> Diselenide) thin film<span> solar cell. In this work, initially a basic CIGS single graded cell structure is optimized in terms of thickness, band-gap and doping concentration. CdS is kept as the buffer layer, which is widely used for high efficiency CIGS solar cells. In the next step, CdS is replaced with ZnMgO as the buffer layer in order to exploit its greater </span></span>photon absorption ability due to its higher band-gap which further enhances the cell efficiency. A thorough analysis is carried out on the solar cell parameters open circuit voltage (V</span></span><sub>oc</sub>), short circuit current density (J<sub>sc</sub><span>), fill factor (FF) and quantum efficiency (η) of the photovoltaic cell structure. An intermediate layer of p-type MoS</span><sub>2</sub><span> is inserted in between the single graded CIGS absorber layers. The objective is to limit the unintentional Ga inter diffusion and maintain the desired grading during the high temperature annealing for the absorber preparation. The power conversion efficiency of the bilayer device structure with Ga fraction x=(0.31) of the top absorber layer along with Ga fraction y=(0.25) of the bottom absorber layer exhibits an improved efficiency from 24.02% (CdS as the buffer layer) to 25.37% (ZnMgO as buffer layer). An excellent power efficiency of η = 26.78% is reported after adding the intermediate layer of p-type MoS</span><sub>2</sub> and optimizing its thickness and the carrier concentration.</p></div>","PeriodicalId":22044,"journal":{"name":"Superlattices and Microstructures","volume":null,"pages":null},"PeriodicalIF":3.3000,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"8","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Superlattices and Microstructures","FirstCategoryId":"101","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0749603621002950","RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"PHYSICS, CONDENSED MATTER","Score":null,"Total":0}
引用次数: 8
Abstract
We present a numerical simulation based study of single graded Cu(In,Ga)Se2 (Copper Indium Gallium Diselenide) thin film solar cell. In this work, initially a basic CIGS single graded cell structure is optimized in terms of thickness, band-gap and doping concentration. CdS is kept as the buffer layer, which is widely used for high efficiency CIGS solar cells. In the next step, CdS is replaced with ZnMgO as the buffer layer in order to exploit its greater photon absorption ability due to its higher band-gap which further enhances the cell efficiency. A thorough analysis is carried out on the solar cell parameters open circuit voltage (Voc), short circuit current density (Jsc), fill factor (FF) and quantum efficiency (η) of the photovoltaic cell structure. An intermediate layer of p-type MoS2 is inserted in between the single graded CIGS absorber layers. The objective is to limit the unintentional Ga inter diffusion and maintain the desired grading during the high temperature annealing for the absorber preparation. The power conversion efficiency of the bilayer device structure with Ga fraction x=(0.31) of the top absorber layer along with Ga fraction y=(0.25) of the bottom absorber layer exhibits an improved efficiency from 24.02% (CdS as the buffer layer) to 25.37% (ZnMgO as buffer layer). An excellent power efficiency of η = 26.78% is reported after adding the intermediate layer of p-type MoS2 and optimizing its thickness and the carrier concentration.
期刊介绍:
Micro and Nanostructures is a journal disseminating the science and technology of micro-structures and nano-structures in materials and their devices, including individual and collective use of semiconductors, metals and insulators for the exploitation of their unique properties. The journal hosts papers dealing with fundamental and applied experimental research as well as theoretical studies. Fields of interest, including emerging ones, cover:
• Novel micro and nanostructures
• Nanomaterials (nanowires, nanodots, 2D materials ) and devices
• Synthetic heterostructures
• Plasmonics
• Micro and nano-defects in materials (semiconductor, metal and insulators)
• Surfaces and interfaces of thin films
In addition to Research Papers, the journal aims at publishing Topical Reviews providing insights into rapidly evolving or more mature fields. Written by leading researchers in their respective fields, those articles are commissioned by the Editorial Board.
Formerly known as Superlattices and Microstructures, with a 2021 IF of 3.22 and 2021 CiteScore of 5.4