Hybrid photovoltaic cells based on ZnO/Sb2S3/P3HT heterojunctions

We demonstrate hybrid photovoltaic (PV) cells based on n–i–p heterojunctions with incorporated zinc oxide (ZnO) films using a sol–gel method. The cells, employing stibnite (Sb2S3), and poly(3‐hexylthiophene) (P3HT) materials, as light absorption layers, constitute an active region in the indium tin oxide (ITO)/ZnO(n)/Sb2S3(i)/P3HT(p)/Ag hybrid structure. Our investigation shows that annealing temperature has a significant effect on both the crystallinity and optical absorption of Sb2S3 films. The near‐intrinsic Sb2S3 films annealed at 300 °C exhibits dark conductivity of 1.42 × 10−7 S cm−1. The performance of PV cells strongly depends on thermal treatment of Sb2S3, and on the thickness of both the Sb2S3 and P3HT layers. Electronic structures of annealed Sb2S3 films was further studied by photoelectron spectroscopy to understand the physics behind.