Mandal Saptarshi, Mukherjee Soumen, De Chayan K, Roy Debjit, Ghosh Swarnali, Mandal Prasun K
J Phys Chem Lett. 2020 Mar 5;11(5):1702-1707. doi: 10.1021/acs.jpclett.0c00385. Epub 2020 Feb 18.
Perovskite quantum dots (PQDs) are known to be defect-tolerant, possessing a clean band gap with optically inactive benign defect states. However, we show that there exist significant deep trap states beyond the conduction band minimum, although the extent of shallow trap states is observed to be minimal. The extent of deep trap states beyond the conduction band minimum seems to be significant in PQDs; however, the extent is less than that of even optically robust CdSe- and InP-based core/alloy-shell QDs. In-depth analyses based on ultrafast transient absorption and ultrasensitive single-particle spectroscopic investigations decode the underlying degree of charge carrier recombination in CsPbBr PQDs, which is quite important for energy applications.
钙钛矿量子点（PQDs）已知具有缺陷容忍性，拥有干净的带隙以及光学上无活性的良性缺陷态。然而，我们表明，尽管观察到浅陷阱态的程度极小，但在导带最小值之外存在显著的深陷阱态。在PQDs中，导带最小值之外的深陷阱态程度似乎很显著；然而，其程度甚至小于光学性能稳定的基于CdSe和InP的核/合金壳量子点。基于超快瞬态吸收和超灵敏单粒子光谱研究的深入分析揭示了CsPbBr PQDs中电荷载流子复合的潜在程度，这对于能量应用非常重要。
