Anush Ranka1,Inseok Yang1,Zhenghong Dai1,Nitin Padture1
Brown University1
Anush Ranka1,Inseok Yang1,Zhenghong Dai1,Nitin Padture1
Brown University1
High performance lab-scale perovskite solar cells (PSCs) with power conversion efficiency (PCE) over 25% have been reported recently. However, most of the reported high-PCE devices have an active area of <0.15 cm<sup>2</sup>, and spin-coating is used to fabricate the perovskite thin films and the electron- and hole-selective transport layers. While future commercialization of PSCs requires us to move to scalable fabrication methods, an increase in sheet/series resistance, inhomogeneity of the film over large areas, loss in active area due to carrier collectors, <i>etc</i>. are inevitable in large scale PSCs. This, along with the technological barriers to entry, makes it difficult to obtain high PCE in PSCs fabricated using scalable processes. To obtain a deeper understanding of the factors that govern these shortcomings, we have investigated the effects of different parameters that need to be controlled to achieve high-quality, large-scale PSCs. We use processes such as chemical bath deposition, and nitrogen ‘knife’ assisted blade-coating and slot-die coating, and discuss the pros and cons of each process. We begin with controlling factors such as solution composition, nitrogen-knife pressure/speed, <i>etc</i>., that have the biggest effects on the film quality, and then move on to other factors such as molarity, humidity, and substrate roughness, which are more relevant to the device performance. This research aspires to make scalable processes more controllable, reliable, and accessible to the PSCs community.