Solution processed double-decked V2Ox/PEDOT:PSS film serves as the hole transport layer of an inverted planar perovskite solar cell with high performance

Abstract

In this paper, we have reported a high-performance inverted planar perovskite solar cell (PSC) with double-decked hole transport layer (HTL) sandwiched between the indium tin oxide (ITO) electrode and the perovskite photoactive layer. The double-decked HTL film is fabricated by coating inorganic vanadium oxide (V₂O_x) layer and poly(3,4-ethylene dioxy-thiophene)–poly(styrene sulfonate) (PEDOT:PSS) layer. In this study, double-decked V₂O_x/PEDOT:PSS HTL film can improve the optoelectronic properties of PSC device. It has been found that the double-decked V₂O_x/PEDOT:PSS film plays a crucial role in enhancing charge transfer rate and suppressing electron–hole pair recombination. The valence of vanadium in the V₂O_x has been changed by adjusting the molar ratio of V₂O₅ to H₂O₂. The PSC can reach its best performance when V₂O₅ and H₂O₂ react at a molar ratio of 1 : 60. In addition, the concentration of the V₂O_x aqueous solution has also been changed to optimize performance of PSC. Hence, the device with double-decked V₂O_x/PEDOT:PSS HTL film can increase the power conversion efficiency (PCE) to 15.86%, higher than that of reference device with PEDOT:PSS (13.56%). Besides, compared with reference device, our device has a better repeatability in the preparation process.