Optically detected spin and spin-orbital resonance studies of CdSe/CdS core-shell nanocrystals

The luminescence spectrum of CdSe/CdS core-shell nanocrystals contains a dominant exciton band located at the CdSe core and an additional weak non-excitonic band, associated with trapped carriers. The present paper describes our efforts to identify the influence of CdSe/CdS interfaces on the localization of the photogenerated species, utilizing optically detected magnetic spin and spin-orbit resonance spectroscopy (ODMR). The spin resonance (SR) spectrum showed two resonance signals: the first associated with a trapped hole in a symmetric site within the core, and a second, corresponding to trapped electrons in an anisotropic interface defect site. The spin-orbital resonance (SOR) signals data is presented.