Unexpected Performances of Flat Sb2S3-Based Hybrid Extremely Thin Absorber Solar Cells

We report unexpected results obtained on hybrid extremely thin absorber (ETA) solar cells based on the structure TiO2/Sb2S3/poly(3-hexylthiophene)/hole conducting layer (HCL). We show that we can maintain a large, state-of-the-art short-circuit current by switching from a three-dimensional to a two-dimensional device, that is, by simplifying drastically the device structure. Moreover, we prove that the HCL plays an important role in the solar cell working mechanism, and influences significantly its open-circuit voltage. We believe that these findings suggest new directions for the optimization of solid-state sensitized solar cells. (c) 2013 The Japan Society of Applied Physics