Photoluminescence of core‐shell CdSe/ZnS quantum dots of different sizes

Abstract

Abstract This paper presents the results of peculiarity analysis in PL spectra of CdSe/ZnS QDs of different sizes. Commercially available CdSe/ZnS core/shell QDs characterized by emission at 525 nm (2.36 eV), 560 nm (2.22 eV), 605 nm (2.05 eV) and 640 nm (1.94 eV) have been studied. PL spectra were measured at excitation by a He‐Cd laser with the light wavelength of 325 nm at the temperatures 10 and 300K. PL spectra of different size QDs can be presented as a superposition of 3 elementary PL bands: (i) PL band deals with ground state exciton emission in a CdSe core and (ii) two PL bands (2.37 and 2.68 eV) assigned to the electron‐hole recombination via interface defects. The spectral positions of defect‐related PL bands did not change versus temperature or QD size. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)