The Preparation And Properties Study Of Multilayer Absorber Thin Film For Cigs Solar Cells

Solar cell is a kind of clean energy that has broad development prospect for its nopollution, low cost and no geographical restrictions, which has been widely used in somecountries and areas. In recent years, many researchers have been devoted to exploitingnext-generation solar cells, one of which is CIGS thin-film solar cell that is regarded as oneof the most development potential thin film solar cell, because of the advantages of highconversion efficiency, high radiation tolerance, excellent weak light response, stableperformance and low cost.At present, a variety of methodes for depositing CIGS films have been proposedamong which only three-stage co-evaporation and sputtering/post-selenization haveachieved small-area solar cells with higher efficiency. However, both methodes arecomplex, high cost and can t be used for large area film deposition, leading to themundesirable application in mass-scale industrial production. Compared to evaporationcoating technology, magnetron sputtering is extraordinarily mature for the deposition ofsemiconductor thin film, which presents great advantages of depositing high compactnessfilm, excellent stoichiometry to transfer target materials, large area uniformity ability andhigh material utilization. Therefore, in this thesis, we try to synthesize the CIGS absorberlayer by magnetron sputtering.In the experiments, the method, consisting of multi-step sputtering process, was usedto respectively deposit CIGS precursors of different Cu content by employing two CIGSquaternary targets which had different composition. We intentionally incorporated aCu-excess growth step to synthesize a layer of Cu-rich CIGS precursor, and Cu2-xSesecondary phase formed in this step can enhance the growth of CIGS grains and improvethe film crystallinity. Meanwhile, the duration of Cu-excess growth step was subtlyadjusted, and the composition, structure, optical and electrical properties of the CIGS filmsprepared under different deposition profiles were in detailed investigated. At last, weobtained simple CIGS thin-film solar cells in which ZnS film deposited by sputtering wasused as buffer layer, then tested and analyzed the performance of the fabricated CIGS solar cells.