ITO Top-Electrodes via Industrial-Scale PLD for Efficient Buffer-Layer-Free Semitransparent Perovskite Solar Cells

The deposition of transparent conductive oxides (TCO) usually employs harsh conditions that are frequently harmful to soft/organic underlayers. Herein, successful use of an industrial pulsed laser deposition (PLD) tool to directly deposit indium tin oxide (ITO) films on semitransparent vacuum-deposited perovskite solar cells without damage to the device stack is demonstrated. The morphological, electronic, and optical properties of the PLD deposited ITO films are optimized. A direct relation between the PLD chamber pressure and the solar cell performance is obtained. The semitransparent perovskite solar cells prepared exclusively by vacuum-assisted techniques had fill factors of 78% and exceeded 18% in power conversion efficiencies. This demonstrates that the direct deposition of TCO-based top electrodes without protective buffer layers is possible and leads to efficient devices.