Room-Temperature Stimulated Emission and Lasing in Recrystallized Cesium Lead Bromide Perovskite Thin Films
Room-Temperature Stimulated Emission and Lasing in Recrystallized Cesium Lead Bromide Perovskite Thin Films
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DOI：
10.1002/adma.201903717
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发表时间：
2019-08-12
影响因子：
29.4
通讯作者：
Riedl, Thomas
中科院分区：
文献类型：
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作者：
Pourdavoud, Neda;Haeger, Tobias;Riedl, Thomas
铯铅卤化物钙钛矿在发光二极管和激光器方面备受关注。到目前为止，CsPbX3 薄膜通常仅在低温下提供非常低的光致发光量子产率（PL-QY < 20%）和放大自发发射（ASE），因为缺陷相关的非辐射复合在室温（RT）下占主导地位。目前人们认为，为了在室温下实现卤化铅钙钛矿的高效发光，电荷载流子/激子需要被限制在纳米尺度上，就像 CsPbX3 纳米颗粒 (NP) 中一样。这里展示了溴化铯铅薄膜，其在室温下显示出 68% 的高 PL-QY 和低阈值 ASE。沉积层通过热压印进行再结晶，形成连续的薄膜（100% 覆盖基材），由具有微米横向延伸的大晶体组成。使用这些层，第一个铯溴化铅薄膜分布式反馈和垂直腔表面发射激光器在室温下具有超低阈值，不依赖于纳米粒子的使用。预计这些结果将产生超越钙钛矿激光器的更广泛的影响，并将建议对范式进行修改，即 CsPbX3 钙钛矿的高效光发射只能通过纳米粒子实现。
Cesium lead halide perovskites are of interest for light-emitting diodes and lasers. So far, thin-films of CsPbX3 have typically afforded very low photoluminescence quantum yields (PL-QY < 20%) and amplified spontaneous emission (ASE) only at cryogenic temperatures, as defect related nonradiative recombination dominated at room temperature (RT). There is a current belief that, for efficient light emission from lead halide perovskites at RT, the charge carriers/excitons need to be confined on the nanometer scale, like in CsPbX3 nanoparticles (NPs). Here, thin films of cesium lead bromide, which show a high PL-QY of 68% and low-threshold ASE at RT, are presented. As-deposited layers are recrystallized by thermal imprint, which results in continuous films (100% coverage of the substrate), composed of large crystals with micrometer lateral extension. Using these layers, the first cesium lead bromide thin-film distributed feedback and vertical cavity surface emitting lasers with ultralow threshold at RT that do not rely on the use of NPs are demonstrated. It is foreseen that these results will have a broader impact beyond perovskite lasers and will advise a revision of the paradigm that efficient light emission from CsPbX3 perovskites can only be achieved with NPs.