Fully Printed HTL-Free MAPbI3 Perovskite Solar Cells with Carbon Electrodes

This study investigates fully printed methylamine vapour-treated methylammonium lead iodide (MAPbI3) hole transport layer (HTL)-free perovskite solar cells (PSCs) with a carbon electrode. We describe a method that can be used to deposit MAPbI3 films in an ambient environment with doctor blading that is entirely free of spin coating and has precise morphology control, in which the varying input N2 pressure affects the film morphology. Consequently, a fully printed perovskite solar cell with an ITO/SnO2/MAPbI3/carbon structure was fabricated using a doctor-blading SnO2 electron transport layer and a screen-printed carbon counter electrode. The low-temperature-derived PSCs exhibited a superior power conversion efficiency (PCE) of 14.17% with an open-circuit voltage (Voc) of 1.02 V on a small-active-area device and the highest efficiency of >8% for an illumination exposure area of 1.0 cm2, with high reproducibility. This work highlights the potential of doctor blading and methylamine vapour treatment as promising methods for fabricating high-performance perovskite solar cells. A doctor-blading approach offers a wide processing window for versatile high-performance perovskite optoelectronics in the context of large-scale production.