Institute of Spectroscopy RAS, Troitsk, Moscow 108840, Russia.
Lebedev Physical Institute of the Russian Academy of Sciences, Troitsk, Moscow 108840, Russia.
Nano Lett. 2023 Mar 22;23(6):2087-2093. doi: 10.1021/acs.nanolett.2c04004. Epub 2023 Mar 9.
Time-resolved analysis of photon cross-correlation function (τ) is applied to photoluminescence (PL) of individual submicrometer size MAPbI perovskite crystals. Surprisingly, an antibunching effect in the long-living tail of PL is observed, while the prompt PL obeys the photon statistics typical for a classical emitter. We propose that antibunched photons from the PL decay tail originate from radiative recombination of detrapped charge carriers which were initially captured by a very limited number (down to one) of shallow defect states. The concentration of these trapping sites is estimated to be in the range 10-10 cm. In principle, photon correlations can be also caused by highly nonlinear Auger recombination processes; however, in our case it requires unrealistically large Auger recombination coefficients. The potential of the time-resolved (0) for unambiguous identification of charge rerecombination processes in semiconductors considering the actual number of charge carries and defects states per particle is demonstrated.
时间分辨光子相关函数（τ）分析被应用于单个亚微米尺寸的 MAPbI 钙钛矿晶体的光致发光（PL）。令人惊讶的是，在 PL 的长寿命尾部观察到反聚束效应，而瞬态 PL 则遵循典型的经典发射器的光子统计特性。我们提出，PL 衰减尾部中的反聚束光子源自最初被极少数（低至一个）浅陷阱态俘获的离域电荷载流子的辐射复合。这些俘获位置的浓度估计在 10-10 cm 范围内。原则上，光子相关也可以由高度非线性的俄歇复合过程引起；然而，在我们的情况下，这需要不切实际地大的俄歇复合系数。时间分辨（0）技术用于半导体中电荷再复合过程的明确识别，考虑到每个粒子的实际电荷载流子和缺陷态数量，证明了这一技术的潜力。
