Liu, FangzeSidhik, SirajHoffbauer, Mark A.Lewis, SinaNeukirch, Amanda J.Pavlenko, VitalyTsai, HsinhanNie, WanyiEven, JackyTretiak, SergeiAjayan, Pulickel M.Kanatzidis, Mercouri G.Crochet, Jared J.Moody, Nathan A.Blancon, Jean-ChristopheMohite, Aditya D.2021-02-242021-02-242021Liu, Fangze, Sidhik, Siraj, Hoffbauer, Mark A., et al.. "Highly efficient photoelectric effect in halide perovskites for regenerative electron sources." <i>Nature Communications,</i> 12, (2021) Springer Nature: https://doi.org/10.1038/s41467-021-20954-6.https://hdl.handle.net/1911/110101Electron sources are a critical component in a wide range of applications such as electron-beam accelerator facilities, photomultipliers, and image intensifiers for night vision. We report efficient, regenerative and low-cost electron sources based on solution-processed halide perovskites thin films when they are excited with light with energy equal to or above their bandgap. We measure a quantum efficiency up to 2.2% and a lifetime of more than 25 h. Importantly, even after degradation, the electron emission can be completely regenerated to its maximum efficiency by deposition of a monolayer of Cs. The electron emission from halide perovskites can be tuned over the visible and ultraviolet spectrum, and operates at vacuum levels with pressures at least two-orders higher than in state-of-the-art semiconductor electron sources.engThis article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.Journal articles41467-021-20954-6https://doi.org/10.1038/s41467-021-20954-6