Efficient Metal‐Halide Perovskite Photovoltaic Cells Deposited via Vapor Transport Deposition

Photovoltaic cells based on metal‐halide perovskites have exceeded the performance of other thin film technologies and rival the performance of devices based on archetypical silicon. Attractively, the perovskite active layer can be processed via a variety of solution‐ and vapor‐based methods. Herein, emphasis is on the use of vapor transport codeposition (VTD) to process efficient n– i –p photovoltaic cells based on methylammonium lead iodide (MAPbI 3 ). VTD utilizes a hot‐walled reactor operated under moderate vacuum in the range of 0.5–10 Torr. The organic and metal‐halide precursors are heated with the resulting vapor transported by a N 2 carrier gas to a cooled substrate where they condense and react to form a perovskite film. The efficiency of photovoltaic devices based on VTD‐processed MAPbI 3 is found to be highest in films with excess lead iodide content, with champion devices realizing exceeding 12%.