Impact of Hole Transporting Layer (HTL) on the Performance of Tin-Based Perovskite Solar Cells

Abstract

Perovskites solar cells (PSC) constitutes of different thin layers deposited on top of a substrate. Hole Transporting Layer (HTL) plays a significant role on the efficiency of the device owing to its numerous advantages such as good conductivity, solution processable, and suitable energy level that matches with perovskite absorber layer. However, Spiro-OMeTAD is extremely expensive and suffers from low hole mobility. However, it is imperative to search for an alternative to the expensive Spiro-OMeTAD commonly used as HTL in PSC. In this work, the influence of various hole transporting layers (such as CuI, CuSCN, Cu2O, and PEDOT:PSS) on the electrical performance of methyl-ammonium tin-iodide based perovskite solar cells was numerically examined using Solar Capacitance (SCAPS) simulator. To optimize the device performance, the HTL and absorber layer thickness were varied and investigated. The simulation results show that the device performance strongly depends on the absorber layer thickness. Among the four selected HTLs, the best performance was achieved using Cu2O with Voc, Jsc, FF, and PCE of 0.9676 V, 32.8344 mA/cm2, 80.97 %, and 25.72 % respectively. The results obtained from this numerical investigation show the potential of fabricating efficient, inexpensive and stable tin-based perovskite solar cells with inorganic HTL.