Fabrication, spectroscopy, and dynamics of highly luminescent core-shell InP@ZnSe quantum dots.

InP quantum dots of 3 nm in diameter have been prepared using a dehalosilylation reaction and passivated with ZnSe to enhance photoluminescence by 6.8 times. Core-shell InP@ZnSe quantum dots dispersed in n-hexane have then been investigated using time-resolved spectroscopy to understand their photoluminescence dynamics. The observed decay times of 0.1, 7, and 1100 ns have been attributed to the relaxation times of electrons in the conduction band, trap sites, and surface states. The surface-state luminescence of core-shell InP@ZnSe quantum dots having the maximum at 760 nm has been distinguished spectrally and dynamically from their band-edge emission having the maximum at 620 nm or from their trap-site emission having the maximum at 660 nm. Copyright 2010 Elsevier Inc. All rights reserved.