Matthew R. Leyden

Organo‐lead‐halide perovskites are promising materials for solar cell applications with efficiencies now exceeding 26% for single junction, and over 33% for silicon tandem devices. Evaporation has proven viable for industrial scale‐up but presents challenges for perovskite materials. Perovskite precursor is introduced into self‐assembling MeO‐2PACz hole transport layers for application to 4 source perovskite coevaporation. This allows precursors that can be difficult to add via evaporation, like methylammonium chloride. These precursor molecules influence growth during evaporation, film behavior during annealing as measured by photoluminescence, and aid the conversion to perovskite as shown by X‐Ray diffraction. Devices have improved power conversion efficiency and stability compared to a control sample within the same evaporation. The best cells reach ≈21% efficiency and comparable performing ≈20% cells maintain their original efficiency after 1000 h of maximum power tracking at 25 °C. This process provides significant process flexibility for perovskite evaporation and requires no additional steps.

Organo-lead-halide perovskite materials offer a potentially low-cost way to fabricate high-quality optoelectronic devices such as solar cells, light-emitting diodes, and lasers. In this work, we focused on perovskite laser applications. There are many types of perovskite lasers reported such as photonic crystal lasers and distributed feedback lasers. These lasers typically require nanoscale lithography to produce the needed cavity structure, which adds significant complexity and cost. This additional cost is not compatible with a vision of low-cost solution processed lasing films. Within this report, we demonstrate a way of replicating grating patterns in lasing films on low-cost polyethylene terephthalate substrates. The film is formed on the master grating and transferred to the final substrate. The master grating can then be used repeatedly. In this process, there is no need to repeat the lithography process and it does not require an additional material, like a UV-cured resin, to create the laser cavity. The cavity is made from the perovskite material itself. Additionally, the film formation is largely independent of the final substrate, eliminating concerns about solvent-substrate compatibility.