Simple Method for Efficient Slot-Die Coating of MAPbI3 Perovskite Thin Films in Ambient Air Conditions

Anuja Vijayan; Malin B Johansson; Sebastian Svanström; Ute B Cappel; Håkan Rensmo; Gerrit Boschloo

doi:10.1021/acsaem.0c00039

Simple Method for Efficient Slot-Die Coating of MAPbI₃ Perovskite Thin Films in Ambient Air Conditions

ACS Appl Energy Mater. 2020 May 26;3(5):4331-4337. doi: 10.1021/acsaem.0c00039. Epub 2020 Apr 20.

Authors

Anuja Vijayan¹, Malin B Johansson¹, Sebastian Svanström², Ute B Cappel³, Håkan Rensmo², Gerrit Boschloo¹

Affiliations

¹ Department of Chemistry - Ångström Laboratory, Physical Chemistry, Uppsala University, Box 523, SE-751 20 Uppsala, Sweden.
² Department of Physics and Astronomy, Molecular and Condensed Matter Physics, Uppsala University, Box 516, SE-75120 Uppsala, Sweden.
³ Department of Chemistry, Division of Applied Physical Chemistry, KTH Royal Institute of Technology, SE-10044 Stockholm, Sweden.

Abstract

Scalable methods for deposition of lead halide perovskite thin films are required to enable commercialization of the highly promising perovskite photovoltaics. Here, we have developed a slot-die coating process under ambient conditions for methylammonium lead iodide (MAPbI₃) perovskite on heated substrates (about 90 °C on the substrate surface). Dense, highly crystalline perovskite films with large grains (100-200 μm) were obtained by careful adjustment of the deposition parameters, using solutions that are similar but more dilute than those used in typical spin-coating procedures. Without any further after treatments, such as antisolvent treatment or vapor annealing, we achieved power conversion efficiencies up of 14.5% for devices with the following structure: conducting tin oxide glass (FTO)/TiO₂/MAPbI₃/spiro-MeOTAD/Au. The performance was limited by the significant roughness of the deposited films, resulting from the hot-casting method, and the relatively high deposition temperature, which led to a defect-rich surface due to loss of MAI.