Mechanism of Single-Photon Upconversion Photoluminescence in All-Inorganic Perovskite Nanocrystals: The Role of Self-Trapped Excitons
- 24 September 2019
- journal article
- research article
- Published by American Chemical Society (ACS) in The Journal of Physical Chemistry Letters
- Vol. 10 (20), 5989-5996
- https://doi.org/10.1021/acs.jpclett.9b02289
Abstract
The efficient single-photon upconversion photoluminescence (UCPL) feature of lead halide perovskite semiconductors makes it promising for developing laser cooling devices. This is an attractive potential application, but the underlying physics still remains unclear so far. By using the all-inorganic CsPbX3 (X = Br, I) nanocrystal samples, this phenomenon was investigated by photoluminescence (PL) and time-resolved PL under different temperatures and various excitation conditions. A broad emission band located at the low-energy side of the free exciton (FE) peak was detected and deduced to be from the self-trapped exciton (STE). The lifetime of STE emission was found to be 171 ns at 10 K, much longer than that of FE. The UCPL phenomenon was then attributed to thermal activation of transformation from STEs to FEs, and the energy barrier was derived to be 103.7 meV for CsPbBr3 and 45.2 meV for CsPb(Br/I)3, respectively. The transformation also can be seen from the fluorescence decay processes.Funding Information
- Ministry of Science and Technology of the People's Republic of China (2016YFB1102500)
- Ministry of Education of the People's Republic of China
- National Natural Science Foundation of China (11204231, 21373156)
This publication has 55 references indexed in Scilit:
- Upconversion Due to Optical-Phonon-Assisted Anti-Stokes Photoluminescence in Bulk GaNACS Photonics, 2015
- Nanocrystals of Cesium Lead Halide Perovskites (CsPbX3, X = Cl, Br, and I): Novel Optoelectronic Materials Showing Bright Emission with Wide Color GamutNano Letters, 2015
- Trap States in Lead Iodide PerovskitesJournal of the American Chemical Society, 2015
- Laser cooling of a semiconductor by 40 kelvinNature, 2013
- Anti‐Stokes cooling in semiconductor nanocrystal quantum dots: A feasibility studyPhysica Status Solidi (a), 2009
- Photoluminescence upconversion in colloidal CdTe quantum dotsPhysical Review B, 2003
- Optical Studies of Self-Trapped Excitons in CsCl and CsBrJournal of the Physics Society Japan, 1993
- The self-trapped excitonJournal of Physics and Chemistry of Solids, 1990
- Exciton self-trapping in ZnSe-ZnTe alloysPhysical Review Letters, 1987
- Recombination luminescence lifetimes and the self-trapped excition in alkali halidesJournal of Luminescence, 1973