Material Perspective for Hole Transport Material-Free Perovskite Solar Cell: A Mini Review

The technology for converting energy from sunlight (photovoltaic) has entered the third generation. The Perovskite Solar Cell (PSC) can compete with the efficiency of current silicon solar cells. However, from the commercial side, there are still obstacles due to the high price of the hole transport material. This component prevents electrons from being transferred to the anode. It also extracts and transports active layer holes to the electrode. This material can be removed since perovskite material can play a dual role. Perovskite materials can be utilized as light harvesters and hole conductors. However, the absence of one component in the PSC structure certainly affects PSC performance. Therefore, in this review, several developments of hole-transport material-free PSC are discussed regarding the type of material used. It starts from the electron transport layer, perovskite layer, and counter electrode. The TiO2 material is most often used for the electron transport layer because it can achieve a power conversion efficiency (PCE) of >12%. Moreover, with the addition of doping, the PCE value can reach 14.06%. In addition, for the perovskite layer, with a slight modification of the MAPbI3 material, the PCE value is >16%.