The tungsten trioxide(WO_3) thin films were firstly prepared by spin-coating-pyrolysis methods using the ammonium metatungstate((NH_4)_6H_2W_(12)O_(40))DMF/water solution, and successfully applied as the efficient compact layers for the planar perovskite solar cells. The influence of the WO_3 film thickness and the rinsing treatment of CH_3NH_3 PbI_3 thin film with isopropanol on the photovoltaic performance of the corresponding perovskite solar cells was systematically investigated. The results revealed that the perovskite solar cell with a 62 nm thick WO_3 compact layer achieved a photoelectric conversion efficiency of 5.72%, with a short circuit photocurrent density of 17.39 m A/cm^2, an open circuit voltage of 0.58 V and a fill factor of 0.57. The photoelectric conversion efficiency was improved from 5.72% to 7.04% by the isopropanol rinsing treatment.
A hydrolysis process was applied to prepare the compact Ti O2 layer using the fresh metastable Ti Cl4isopropanol/water solution as the precursor solution for the preparation of the inorganic–organic hybrid heterojunction perovskite solar cells. The optimal compact Ti O2 layer prepared from the aqueous solution of 2 mol/L Ti Cl4 diluted in isopropanol at 1 : 3 by volume as precursor solution was uniform and with a film thickness of 126 nm.The corresponding perovskite solar cell gave a photovoltaic conversion efficiency of 10.61%.
