All-inorganic cesium lead bromide (CsPbBr3) perovskite quantum dots (QDs) with excellent optical properties have been regarded as good gain materials for amplified spontaneous emission (ASE). However, the poor stability as the results of the high sensitivity to heat and moisture limits their further applications. Here, we report a facile one-pot approach to synthesize CsPbBr3@SiO2 QDs at room temperature. Due to the effective defects passivation using SiO2, as-prepared CsPbBr3@SiO2 QDs present an enhanced photoluminescence quantum yield (PLQY) and chemical stability. The PLQY of CsPbBr3@SiO2 QDs reaches 71.6% which is higher than 46% in pure CsPbBr3 QDs. The PL intensity of CsPbBr3@SiO2 QDs maintains 84% while remaining 24% in pure CsPbBr3 after 80 min heating at 60°C. The ASE performance of the films is also studied under a two-photon-pumped laser. Compared with the films using pure CsPbBr3 QDs, those with as-prepared CsPbBr3@SiO2 QDs exhibit a reduced threshold of ASE. The work suggests that room-temperature-synthesized SiO2-coated perovskites QDs are promising candidates for laser devices.

中文翻译：

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用于放大自发发射的稳定二氧化硅包覆 CsPbBr3 量子点的室温合成

具有优异光学性能的全无机溴化铯铅 (CsPbBr3) 钙钛矿量子点 (QD) 被认为是放大自发发射 (ASE) 的良好增益材料。然而，由于对热和湿气高度敏感而导致的稳定性差限制了它们的进一步应用。在这里，我们报告了一种在室温下合成 CsPbBr3@SiO2 QD 的简便方法。由于使用 SiO2 进行有效的缺陷钝化，所制备的 CsPbBr3@SiO2 QD 具有增强的光致发光量子产率 (PLQY) 和化学稳定性。CsPbBr3@SiO2量子点的PLQY达到71.6%，高于纯CsPbBr3量子点的46%。在 60°C 加热 80 分钟后，CsPbBr3@SiO2 QDs 的 PL 强度保持在 84%，而在纯 CsPbBr3 中保持 24%。薄膜的 ASE 性能也在双光子泵浦激光器下进行了研究。与使用纯 CsPbBr3 QD 的薄膜相比，那些具有制备好的 CsPbBr3@SiO2 QD 的薄膜表现出降低的 ASE 阈值。这项工作表明，室温合成的 SiO2 涂层钙钛矿 QD 是激光器件的有希望的候选者。