Zhou Xiaohe, Bose Riya, Zhu Xiangyu, Mehta Abhas, Kim Moon J, Malko Anton V
J Phys Chem Lett. 2023 Mar 30;14(12):2933-2939. doi: 10.1021/acs.jpclett.3c00219. Epub 2023 Mar 17.
We utilized a modified reverse-microemulsion method to develop highly emissive and photostable zero-dimensional (0D) CsPb(BrI) perovskite nanocrystals (PNCs). We employed single-particle photoluminescence (PL) spectroscopy to explore blinking statistics and demonstrate single-photon emission from individual PNCs. Low-temperature blinking and photon correlation studies revealed a transition from single- to multiphoton emission with progressively longer "delayed" PL components, reaching ∼70 ns at room temperature and representing a distinctive behavior to previously known iodide PNCs. Such thermally activated PL emission is explained by the existence of defect-related "reservoir" states, feeding back into the PNC's emissive state and providing multiple photons within a single excitation cycle. This work establishes a new member in the 0D class of perovskite materials, studies its photophysical properties, and reveals its potential for future optoelectronic applications.
我们采用一种改进的反相微乳液法来制备高发光性和光稳定性的零维（0D）CsPb(BrI)钙钛矿纳米晶体（PNCs）。我们利用单粒子光致发光（PL）光谱来探究闪烁统计，并证明单个PNC的单光子发射。低温闪烁和光子相关性研究表明，随着“延迟”PL分量逐渐变长，会从单光子发射转变为多光子发射，在室温下达到约70纳秒，这代表了与先前已知的碘化物PNC不同的行为。这种热激活PL发射可通过与缺陷相关的“库”态的存在来解释，这些态反馈到PNC的发射态，并在单个激发周期内提供多个光子。这项工作在0D类钙钛矿材料中建立了一个新成员，研究了其光物理性质，并揭示了其在未来光电子应用中的潜力。
