Low-damage hydrogen-doped transparent electrodes towards semitransparent perovskite photovoltaics

As one kind of transparent conductive electrodes (TCEs), transparent conductive oxides (TCOs) have been widely used in perovskite solar cells (PSCs). However, the conventional magnetron sputtering usually causes high-energy particles, thus damaging the underlying functional films and deteriorating the performance of devices. Therefore, developing a low-damage method for high-quality TCO film is crucial. Here, the hydrogen and cerium co-doped indium oxide (ICO:H) films were prepared by the reactive plasma deposition (RPD) technology at room temperature. Benefiting from the hydrogen doping, the bandgap of the ICO:H film was tuned to 3.97 eV, the average transmittances reached 91.25% (from 800 nm to 1200 nm) and 81.35% (from 300 nm to 800 nm), and the carrier mobility exceeded 30 cm2/V/s. Combined with these advantages, semitransparent perovskite solar cells (ST-PSCs) without buffer layers were fabricated using ICO:H films as transparent conductive window layers, and the power conversion efficiency (PCE) was up to 17.61% (from the glass side). Furthermore, the ICO:H films were also applied in two-terminal perovskite/silicon tandem solar cells, and the PCE exceeded 25%. This low-damage method opens a new avenue for fabricating film-based optoelectronics.