Kamau Steve, Rodriguez Roberto Gonzalez, Jiang Yan, Mondragon Araceli Herrera, Varghese Sinto, Hurley Noah, Kaul Anupama, Cui Jingbiao, Lin Yuankun
Department of Physics, University of North Texas, Denton, TX 76203, USA.
Department of Materials Science and Engineering, University of North Texas, Denton, TX 76203, USA.
Micromachines (Basel). 2023 Aug 31;14(9):1706. doi: 10.3390/mi14091706.
Organic-inorganic perovskites hold great promise as optoelectronic semiconductors for pure color light emitting and photovoltaic devices. However, challenges persist regarding their photostability and chemical stability, which limit their extensive applications. This paper investigates the laser radiation hardening and self-healing-induced properties of aged MAPbBr perovskites encapsulated in NiO nanotubes (MAPbBr@NiO) using photoluminescence (PL) and fluorescence lifetime imaging (FLIM). After deliberately subjecting the MAPbBr@ NiO to atmospheric conditions for two years, the sample remains remarkably stable. It exhibits no changes in PL wavelength during UV laser irradiation and self-healing. Furthermore, exposure to UV light at 375 nm enhances the PL of the self-healed MAPbBr@NiO. FLIM analysis sheds light on the mechanism behind photodegradation, self-healing, and PL enhancement. The results indicate the involvement of many carrier-trapping states with low lifetime events and an increase in peak lifetime after self-healing. The formation of trapping states at the perovskite/nanotube interface is discussed and tested. This study provides new insights into the dynamics of photo-carriers during photodegradation and self-healing in organic-inorganic perovskites.
有机-无机钙钛矿作为用于纯色发光和光伏器件的光电子半导体具有巨大潜力。然而，它们的光稳定性和化学稳定性方面仍然存在挑战，这限制了它们的广泛应用。本文利用光致发光（PL）和荧光寿命成像（FLIM）研究了封装在NiO纳米管（MAPbBr@NiO）中的老化MAPbBr钙钛矿的激光辐射硬化和自愈合诱导特性。在将MAPbBr@NiO有意置于大气条件下两年后，样品仍保持显著稳定。在紫外激光照射和自愈合过程中，其PL波长没有变化。此外，暴露于375 nm紫外光可增强自愈合后的MAPbBr@NiO的PL。FLIM分析揭示了光降解、自愈合和PL增强背后的机制。结果表明存在许多具有低寿命事件的载流子捕获态，且自愈合后峰值寿命增加。讨论并测试了钙钛矿/纳米管界面处捕获态的形成。这项研究为有机-无机钙钛矿光降解和自愈合过程中光载流子的动力学提供了新的见解。
