Zhongdong Zhao,Yihan Qi,Qiuying Chen,Xuerong Zheng,Qiuyan Hao,Wen Zhang,Jing Mao,Caichi Liu,Hui Liu
Compared with the expensive and complicated vacuum techniques, the solution-based process to deposit I-III-VI 2 chalcogenide thin films (I=Cu, III=In or Ga, VI=S or Se) has attracted great interests due to its lower cost, higher scalable production and better application in flexible substrate . Herein, a low-toxic and high-active mixture solvent comprised of 1, 2-ethanedithiol and 1,2-ethylenediamine is utilized to dissolve elemental Cu, In and S powders at 60 °C, forming the CuInS 2 (CIS) precursor solution . After spin coating and annealing in a both Ar gas and selenium atmosphere, a dense and large-grained chalcopyrite CuIn(S,Se) 2 (CISSe) thin films with a close-packed grain size of ~800 nm are prepared, eliminating a undesired fine fine-grained bottom layer. In addition, the selenization temperature of the CISSe thin films is also discussed, which influences the phase composition, crystallinity and morphology of CISSe thin films. Photovoltaic device of the CISSe-based thin films is fabricated, obtaining a power conversion efficiency of 6.2% with an active cell area of 0.5 cm 2 under AM 1.5 illumination.
Cu 2 ZnSnSe 4 (CZTSe) solar cell with a facile superstrate structure of carbon/CZTSe/CdS/ITO was fabricated entirely by non-vacuum processes. The influence of selenization temperature on the composition of CZTSe layer was briefly investigated. Compared with current superstrate-type CZTS(e) solar cells, the present CZTSe superstrate solar cell exhibited a higher power conversion efficiency of 2.44%.