Indirect Exciton Formation due to Inhibited Carrier Thermalization in Single CdSe/CdS Nanocrystals

Abstract

Temperature-dependent single-particle spectroscopy is used to study interfacial energy transfer in model light-harvesting CdSe/CdS core-shell tetrapod nanocrystals. Using alternating excitation energies, we identify two thermalized exciton states in single nanoparticles that are attributed to a strain-induced interfacial barrier. At cryogenic temperatures, emission from both states exemplifies the effects of intraparticle disorder and enables their simultaneous characterization, revealing that the two states are distinct in regards to emission polarization, spectral diffusion, and blinking.