Long-Lived Delocalized Electron States in Quantum Dots: A Step-Scan Fourier Transform Infrared Study
journal contributionposted on 01.02.2000, 00:00 by Moonsub Shim, Sergej V. Shilov, Mark S. Braiman, Philippe Guyot-Sionnest
Visible light-induced IR absorption in colloidal CdSe quantum dots is observed by step-scan FTIR spectroscopy. Size dependence and the effect of surface modification are investigated. The introduction of surface hole trap states enhances and prolongs the IR absorption in photoexcited quantum dots. Our measurements reveal long-lived (>1 ms) delocalized electron states in 6 nm average diameter dots capped with thiocresol.