The effect of low temperature coating and annealing on structural and optical properties of CdSe/CdS core/shell QDs

M. Isarov; N. Grumbach; G.I. Maikov; J. Tilchin; Y. Jang; A. Sashchiuk; E. Lifshitz

doi:10.3952/physics.v55i4.3227

M. Isarov
N. Grumbach
G.I. Maikov
J. Tilchin
Y. Jang
A. Sashchiuk
E. Lifshitz

DOI: https://doi.org/10.3952/physics.v55i4.3227

Keywords: CdSe/CdS core/shell structures, colloidal quantum dots, excitons, photoluminescence

Abstract

This paper presents the optical temperature dependent properties, over a wide range of temperatures from 4 to 300 K, of new CdSe/CdS core/shell colloidal quantum dots (QDs) with varying shell thickness coated and annealed at low temperature. It was demonstrated that low temperature coating and annealing processes enhanced the photoluminescence (PL) quantum yield accompanied by variation in the QDs structure, formation of an alloyed interface layer, suppression of the number of defects at the CdSe/CdS interface, band gap energy red-shift, narrowing of CdS longitudinal optical phonon band, and decrease of the PL inhomogeneous broadening parameter.