Milotti Valeria, Cacovich Stefania, Ceratti Davide Raffaele, Ory Daniel, Barichello Jessica, Matteocci Fabio, Di Carlo Aldo, Sheverdyaeva Polina M, Schulz Philip, Moras Paolo
Istituto di Struttura della Materia - CNR (ISM-CNR), Trieste, I-34149, Italy.
Institut Photovoltaïque d'Île de France (IPVF), CNRS, Ecole Polytechnique, IP Paris, Palaiseau, 91120, France.
Small Methods. 2023 Sep;7(9):e2300222. doi: 10.1002/smtd.202300222. Epub 2023 Jun 7.
The extensive use of perovskites as light absorbers calls for a deeper understanding of the interaction of these materials with light. Here, the evolution of the chemical and optoelectronic properties of formamidinium lead tri-bromide (FAPbBr ) films is tracked under the soft X-ray beam of a high-brilliance synchrotron source by photoemission spectroscopy and micro-photoluminescence. Two contrasting processes are at play during the irradiation. The degradation of the material manifests with the formation of Pb metallic clusters, loss of gaseous Br , decrease and shift of the photoluminescence emission. The recovery of the photoluminescence signal for prolonged beam exposure times is ascribed to self-healing of FAPbBr , thanks to the re-oxidation of Pb and migration of FA and Br ions. This scenario is validated on FAPbBr films treated by Ar ion sputtering. The degradation/self-healing effect, which is previously reported for irradiation up to the ultraviolet regime, has the potential of extending the lifetime of X-ray detectors based on perovskites.
钙钛矿作为光吸收剂的广泛应用需要更深入地了解这些材料与光的相互作用。在此，通过光电子能谱和微光致发光，在高亮度同步加速器源的软X射线束下跟踪了甲脒三溴化铅（FAPbBr₃）薄膜的化学和光电性质的演变。在辐照过程中，有两个相反的过程在起作用。材料的降解表现为铅金属团簇的形成、气态溴的损失、光致发光发射的减少和位移。长时间束曝光时光致发光信号的恢复归因于FAPbBr₃的自愈，这得益于铅的再氧化以及FA和Br离子的迁移。这种情况在经过氩离子溅射处理的FAPbBr₃薄膜上得到了验证。先前报道的直至紫外区域辐照的降解/自愈效应，有延长基于钙钛矿的X射线探测器寿命的潜力。
