Photophysics as a Tool to Measure the Surface-State of Perovskite Nanoparticles
Jixin Chen, Department of Physics, Ohio University
The photoluminescence (PL) of organolead halide perovskites (OHPs) is sensitive to OHPs’ surface conditions and an effective way to report surface states. OHP is a hot semiconducting material that has a large potential in solar cells and LEDs. Photophysics describes the light-matter interactions in the materials using several phenomena such as absorption, exciton relaxation, emission quantum yield, photoblinking, and photodarkening/photobleaching. In this seminar, Dr. Chen will focus his talk on the photoblinking and photodarkening of perovskite nanoparticles. These two processes are extremely sensitive to the surface states of the nanoparticles which can be tuned by the absorption and desorption of oxygen molecules at the solid-ligand-gas interfaces. A major tool Dr. Chen used in this study is kinetics, i.e. fitting the time-dependent PL trajectories of single-nanoparticles into a kinetic model. By reducing the oxygen concentration and the number of exposed surface sites on the perovskite nanoparticles, single-molecule oxygen sensitivity of PL can be observed.
Host: Lydia Kisley