Structure engineering of solution-processed precursor films for low temperature fabrication of CuIn(S,Se)2 solar cells

摘要: Abstract Fabrication of flexible Cu(In,Ga)(S,Se)2 (CIGS) thin-film solar cell via precursor solution is a promising approach due to its perfect compatibility with roll-to-roll production. So far, polyimide (PI) the most suitable substrate for CIGS because many advantages such as low cost, light weight, good insulativity and free metallic impurities. However, PI has not been used in solution-processed cannot tolerate annealing process (selenization) at high temperature (≥550 °C) which normally required highly efficient cells fabricated solution. Here, we report (450 °C) fabrication CuIn(S,Se)2 (CISSe) absorber by carefully engineering structure film. By adding extra Cu2S into CuInS2 (CIS) films through Mo/In2S3/Cu2S (bilayer), Mo/CIS/Cu2S/(CIS/Cu2S)3/CIS (multilayer), enough Cu2−xSe formed selenization facilitates formation CISSe absorber. Characterizations using XRD, Raman, SEM EDX show that absorbers from new structures favor sufficient selenization, resulting much better morphology higher photovoltaic performance than film normal Mo/CIS (single layer). After preliminary optimization, efficiencies 5.01% 6.13% have achieved only 3.83% structure. Our results demonstrate feasibility fabricating chalcopyrite selenization.