Andrew Christy

Chemistry and Biochemistry

Faculty Advisor: Prashant Kamat

Triplet Sensitization in Semiconductor Nanocrystals

Harvesting light to drive chemical reactions, known as photocatalysis, requires the careful control of energy. Recently, lead halide perovskite nanomaterials have been demonstrated to have a wide range of beneficial properties for photocatalysis: strong light absorption, tunable optoelectronic properties, and ease of synthesis. One way to harvest the energy from perovskite nanomaterials is to store that energy in long-lived molecular states called triplets. These triplet states can be used to increase visible light absorption through photon upconversion or can be used to drive photocatalytic reactions. In this study, migration of energy from perovskite nanomaterials to triplet-accepting molecules will be studied. Cesium lead bromide (CsPbBr3) nanocrystals will be synthesized, and the model triplet acceptor thionine will be used as a probe molecule to study triplet interactions. The effect of the nanocrystal morphology on the triplet interaction will also be probed by synthesizing both nanocubes and nanoplatelets of CsPbBr3. Absorption, photoluminescence, and transient absorption spectroscopies will be taken and these measurements will be used to probe the excited state interactions between CsPbBr3 and thionine.