Efficient up-conversion photoluminescence in all-inorganic lead halide perovskite nanocrystals
up-conversion photoluminescence, phonons, lead halide perovskite, colloidal nanocrystals
Up-conversion photoluminescence (UCPL) refers to the elementary process where low-energy photons are converted into high-energy ones via consecutive interactions inside a medium. When additional energy is provided by internal thermal energy in the form of lattice vibrations (phonons), the process is called phonon-assisted UCPL. Here, we report the exceptionally large phonon-assisted energy gain of up to ~ 8kBT (kB is Boltzmann constant, T is temperature) on all-inorganic lead halide perovskite semiconductor colloidal nanocrystals that goes beyond the maximum capability of only harvesting optical phonon modes. By systematic optical study in combination with a statistical probability model, we explained the nontrivial phonon-assisted UCPL process in perovskites nanocrystals, where in addition to the strong electron–phonon (light-matter) coupling, other nonlinear processes such as phonon–phonon (matter–matter) interaction also effectively boost the up-conversion efficiency.
Tsinghua University Press
Andrés Granados del Águila,T. Thu Ha Do,Jun Xing,Wen Jie Jee,Jacob B. Khurgin,Qihua Xiong, Efficient up-conversion photoluminescence in all-inorganic lead halide perovskite nanocrystals. NanoRes.2020, 13(7): 1962–1969