White-light emission from organics-capped ZnSe quantum dots and application in white-light-emitting diodes

Abstract

Organics-capped ZnSe quantum dots were synthesized by a colloidal chemical approach using ZnO and Se powder as precursors. The photoluminescence of the specimens showed strong white emission (~200 nm full width at half maximum) in the visible range under ambient conditions. The white emission was attributed to the mixing of blue emission of ZnSe nanocrystals exhibiting quantum confinement effect with green-red emission of radiative deep levels from ZnSe surface strained lattice. Based on organic-capped ZnSe quantum dots, the white-light-emitting diodes were fabricated using a near-UV InGaN chip as the excitation source. The diodes emitted white light with CIE chromaticity coordinates of (0.38 and 0.41) and show great potential for use in lighting applications. © 2005 American Institute of Physics.