The Photo-CD team published a new article:
Harshita Bhatia, Cristina Martin, Masoumeh Keshavarz, Iurii Dovgaliuk, Nadine J. Schrenker, Martin Ottesen, Weiming Qiu, Eduard Fron, Martin Bremholm, Joris Van de Vondel, Sara Bals, Maarten B.J. Roeffaers, Johan Hofkens, and Elke Debroye
ACS Applied Materials & Interfaces 2023, 15, 7294-7307. DOI: 10.1021/acsami.2c20605
Abstract:
Lead halide perovskites are promising candidates for high-performance light-emitting diodes (LEDs); however, their applicability is limited by their structural instability toward moisture. Although a deliberate addition of water to the precursor solution has recently been shown to improve the crystallinity and optical properties of perovskites, the corresponding thin films still do not exhibit a near-unity quantum yield. Herein, we report that the direct addition of a minute amount of water to post-treated formamidinium lead bromide (FAPbBr3) nanocrystals (NCs) substantially enhances the stability while achieving a 95% photoluminescence quantum yield in a NC thin film. We unveil the mechanism of how moisture assists in the formation of an additional NH4Br component. Alongside, we demonstrate the crucial role of moisture in assisting localized etching of the perovskite crystal, facilitating the partial incorporation of NH4+, which is key for improved performance under ambient conditions. Finally, as a proof-of-concept, the application of post-treated and water-treated perovskites is tested in LEDs, with the latter exhibiting a superior performance, offering opportunities toward commercial application in moisture-stable optoelectronics.