Preparation and characterization of planar heterojunction perovskite solar cells based on c-TiO 2 /CH 3 NH 3 PbI 3 /HTM/Ag structure

In this paper, A modified one-step method was used to prepare the CH 3 NH 3 PbI 3 (MAPbI 3 ) perovskite film, and the planar heterojunction perovskite solar cells (PHPSCs) were assembled by optimizing the preparation process of the TiO 2 compact layer (c-layer) and perovskite film. A TiO 2 c-layer as the electron transfer layers (ETLs) was controlled by the spin coating method with the different TiO 2 precursor solution and the number of spin coating. The perovskite layer, as a light absorption layer, was obtained by spin coating on the TiO 2 c-layer with MAPbI 3 precursor solutions of different mass concentrations. The characterization results show that although the preparation process is different, the surface morphology of TiO 2 c-layer and perovskite layer are not very different, but there are some fluctuations in the thickness and internal structure of their films. The planar solar cell devices with c-TiO 2 /MAPbI 3 /HTM/Ag structure showed different photoelectric conversion performance. By optimizing the preparation process, the photoelectric conversion efficiency of the assembled solar cell device can reach 12.11% based on a TiO 2 c-layer obtained by two-spin coating with 0.1 M precursor solution and the perovskite layer obtained by spin coating with a mass concentration of 45% in MAPbI 3 solution.