论文标题
强烈量子限制的CSPBBR $ _3 $纳米晶体的强烈深色激子排放
Intense Dark Exciton Emission from Strongly Quantum Confined CsPbBr$_3$ Nanocrystals
论文作者
论文摘要
半导体纳米晶体中的暗基状态激子引起了人们的关注，因为它的长寿对于需要长寿命电子或自旋状态的应用有吸引力。最近，与其他现有的半导体纳米晶体相比，在金属卤化物钙钛矿纳米晶体中探索和获取深色激子水平的努力。然而，在金属卤化物钙钛矿纳米晶体中，直接观察到来自深色激子的长寿命光致发光仍然难以捉摸。在这里，我们报告了深层基态激子的强烈发射的观察，其中1-10个美国寿命在强量的CSPBBR3纳米晶体中观察到，这与迄今为止探索的弱受限制系统的行为形成了鲜明对比。该研究在CSPBBR3纳米晶体中具有不同程度的限制程度，揭示了量子约束在增强明亮黑暗的激子级分裂中至关重要的作用，这对于访问深色激子至关重要。我们的工作展示了强烈量子限制的钙钛矿纳米晶体作为利用深色激子的新平台的未来潜力。
Dark ground state exciton in semiconductor nanocrystals has been a subject of much interest due to its long lifetime attractive for applications requiring long-lived electronic or spin states. Significant effort has been made recently to explore and access the dark exciton level in metal halide perovskite nanocrystals, which are emerging as a superior source of photons and charges compared to other existing semiconductor nanocrystals. However, the direct observation of long-lived photoluminescence from dark exciton has remained elusive in metal halide perovskite nanocrystals. Here, we report the observation of the intense emission from dark ground state exciton with 1-10 us lifetime in strongly quantum confined CsPbBr3 nanocrystals, which contrasts the behavior of weakly confined system explored so far. The study in CsPbBr3 nanocrystals with varying degree of confinement has revealed the crucial role of quantum confinement in enhancing the bright-dark exciton level splitting which is important for accessing the dark exciton. Our work demonstrates the future potential of strongly quantum-confined perovskite nanocrystals as a new platform to utilize dark excitons.
