Electron Beam Evaporated Nickel Oxide Hole Transport Layers for Perovskite Based Photovoltaics

High amp; 8208;quality charge carrier transport materials are of key importance for stable and efficient perovskite amp; 8208;based photovoltaics. This work reports on electron amp; 8208;beam amp; 8208;evaporated nickel oxide NiOx layers, resulting in stable power conversion efficiencies PCEs of up to 18.5 when integrated into solar cells employing inkjet amp; 8208;printed perovskite absorbers. By adding oxygen as a process gas and optimizing the layer thickness, transparent and efficient NiOx hole transport layers HTLs are fabricated, exhibiting an average absorptance of only 1 . The versatility of the material is demonstrated for different absorber compositions and deposition techniques. As another highlight of this work, all amp; 8208;evaporated perovskite solar cells employing an inorganic NiOx HTL are presented, achieving stable PCEs of up to 15.4 . Along with good PCEs, devices with electron amp; 8208;beam amp; 8208;evaporated NiOx show improved stability under realistic operating conditions with negligible degradation after 40 h of maximum power point tracking at 75 C. Additionally, a strong improvement in device stability under ultraviolet radiation is found if compared to conventional perovskite solar cell architectures employing other metal oxide charge transport layers e.g., titanium dioxide . Finally, an all amp; 8208;evaporated perovskite solar mini amp; 8208;module with a NiOx HTL is presented, reaching a PCE of 12.4 on an active device area of 2.3 cm