The buffer – Free semitransparent perovskite solar cells with ion-beam sputtered back electrode

Semitransparent perovskite solar cells (PSCs) have the potential for utilization in tandem photovoltaics (PV) and see-through PV for building integration. The passage of light through the thin-film device structure requires transparent contact at the front and back sides of the device. Typically, transparent contacts are made of wide bang-gap conductive oxides (In₂O₃:SnO₂(ITO), etc.) deposited by magnetron sputtering (MS). The use of conventional MS usually requires the addition of a buffer layer to avoid the damage of the charge transporting layers. In this work, the semitransparent perovskite solar cell with p-i-n architecture is fabricated with ITO back electrode deposited directly on C₆₀ electron transporting layer. A comparative analysis was conducted to evaluate the performance and properties of ITO films deposited using ion-beam sputtering (IBS) and the more common MS method. The IBS process was found to eliminate plasma-substrate interaction, resulting in improved deposition on organic layers. Conversely, the MS method resulted in poor output performance and S-shaped IV characteristics of the semitransparent-PSCs. By utilizing IBS fabrication for the back electrode, the relevant efficiency of 12.65% was achieved for the best device. The changes in chemical, optical, and transport properties of the ITO samples fabricated with different methods were investigated. This study represents the first successful utilization of ion-beam sputtering for the fabrication of semitransparent PSCs.