Current Photovoltaic Research ISSN:2288-3274(Print) 2508-125X(Online)

We investigated current-voltage (I-V) and capacitance (C)-V characteristics of solution-processed thin film solar cells, consisting of Cu(In,Ga)S₂ and CuInS₂ stacked absorber layers. The ideality factors, extracted from the temperature-dependent I-V curves, showed that the tunneling-mediated interface recombination was dominant in the cells. Rapid increase of both series- and shuntresistance at low temperatures would limit the performance of the cells, requiring further optimization. The C-V data revealed that the carrier concentration of the CuInS₂ layer was about 10 times larger than that of the Cu(In,Ga)S₂ layer. All these results could help us to find strategies to improve the efficiency of the solution-processed thin film solar cells.