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Thin‐film Cu(In,Ga)(Se,S) 2 ‐based solar cell with (Cd,Zn)S buffer layer and Zn 1− x Mg x O window layer
Author(s) -
Chantana Jakapan,
Kato Takuya,
Sugimoto Hiroki,
Minemoto Takashi
Publication year - 2017
Publication title -
progress in photovoltaics: research and applications
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.286
H-Index - 131
eISSN - 1099-159X
pISSN - 1062-7995
DOI - 10.1002/pip.2879
Subject(s) - solar cell , layer (electronics) , band gap , zinc , analytical chemistry (journal) , quantum efficiency , materials science , energy conversion efficiency , sputtering , thin film , chemistry , optoelectronics , nanotechnology , metallurgy , chromatography
(Cd,Zn)S buffer layer and Zn 1− x Mg x O window layer were investigated to replace the traditional CdS buffer layer and ZnO window layer in Cu(In,Ga)(Se,S) 2 (CIGSSe)‐based solar cell. (Cd,Zn)S with band‐gap energy ( E g ) of approximately 2.6 eV was prepared by chemical bath deposition, and Zn 1− x Mg x O films with different [Mg]/([Mg] + [Zn]) ratios, x , were deposited by radio frequency magnetron co‐sputtering of ZnO and MgO. The estimated optical E g of Zn 1− x Mg x O films is linearly enhanced from 3.3 eV for pure ZnO ( x = 0) to 4.1 eV for Zn 0.6 Mg 0.4 O ( x = 0.4). The quality of the Zn 1− x Mg x O films, implied by Urbach energy, is severely deteriorated when x is above 0.211. Moreover, the temperature‐dependent current density‐voltage characteristics of the CIGSSe solar cells were conducted for the investigation of the heterointerface recombination mechanism. The external quantum efficiency of the CIGSSe solar cell with the (Cd,Zn)S buffer layer/Zn 1− x Mg x O window layer is improved in the wavelength range of 320–520 nm. Therefore, a gain in short‐circuit current density up to about 5.7% was obtained, which is higher conversion efficiency of up to around 5.4% relative as compared with the solar cell with the traditional CdS buffer layer/ZnO window layer. The peak efficiency of 19.6% was demonstrated in CIGSSe solar cell with (Cd,Zn)S buffer layer and Zn 1− x Mg x O window layer, where x is optimized at 0.211. Copyright © 2017 John Wiley & Sons, Ltd.