Fabrication of inverted planar perovskite solar cells using the iodine/ethanol solution method for copper iodide as a hole transport layer

Copper iodide (CuI) is under extensive research due to its low cost, easy fabrication process, and wide bandgap. This research includes the fabrication of perovskite solar cells using the p-i-n structure (inverted structure) with a focus on the hole transport layer (HTL) layer. In this paper, we demonstrate the applicability of using CuI as a HTL in perovskite solar cells using the iodine/ethanol solution method. Using the iodine/ethanol solution for preparing the CuI, a power conversion efficiency of 0.76%, a short-circuit current density of 4.56 mA cm(-2), an open-circuit voltage of 0.494 V as well as a fill factor of 0.34 were obtained. The overall performance of the solar cell still requires much improvement. We have successfully deposited the CuI using RF magnetron sputtering and the iodine/ethanol solution method and understand that the low performance of the device is mainly due to the voids and gaps present within the CuI layer.