Optimization of Spin Coated TiO2 Layer for Hole-Free Perovskite Solar Cell

Abstract

The optimization of the TiO2 layer in free-hole perovskite solar cells is critical, as it strongly affects the device performance. In this study, simple FTO/TiO2/CH3NH3PbI3/C solar cells were fabricated, via two-step dipping method, with different thickness of TiO2 layer. The structure and microstructure of the TiO2 layers were investigated by X-Ray diffraction (XRD), Raman spectroscopy, and UV spectroscopy (UV-vis). The effect of different TiO2 thickness on the structure and photovoltaic performance of the fabricated devices were investigated using XRD and IV measurement, respectively. The photovoltaic parameters, including short-circuit-current (Jsc), open-circuit-voltage (Voc), Fill factor (F.F) and power conversion efficiency (PCE), were found to be strongly dependent on the thickness of TiO2 layer. The investigation showed that, efficient device can be fabricated by optimizing the TiO2 thickness, employing a thickness of 108 nm as an optimum thickness in this study.