Exploring the growth of MAPbI3 under different preparation methods for mesoporous perovskite solar cells

The control of the perovskite growth morphology plays an extremely critical role in mesoporous perovskite solar cells. In this paper, anatase TiO 2 nanoparticles (NPs) with high crystallinity were synthesized by a hydrothermal method, and the thickness of the TiO 2 mesoporous film (TiO 2 -MT) was adjusted with concentration of TiO 2 -NP slurry by controlling ethanol. The perovskite layers were prepared by the traditional two-step (TTS) method, and the improved two-step (ITS) method was used. It is proved that different preparation processes of the perovskite light-absorbing layers have a certain influence on the photoelectric performance of the cell device, but also, the thickness of the TiO 2 mesoporous film affects the electron transport efficiency at the TiO 2 /MAPbI 3 interface and the suppression of electron–hole recombination through [Formula: see text]–[Formula: see text] positive and negative scanning, electrochemical impedance spectroscopy (EIS) and dark state [Formula: see text]–[Formula: see text] curve analysis of the device. By optimizing the thickness of the TiO 2 mesoporous film, the short-circuit photocurrent density ([Formula: see text] of mesoporous perovskite solar cells (M-PSCs) based on the TiO 2 mesoporous electron transporting layer of 400 nm thickness is 23.85 mA/cm 2 , and the optimal photoelectric conversion efficiency (PCE) is 15.38%.