Influence of interfacial oxide on the optical properties of single layer CdTe/CdS quantum dots in porous silicon scaffolds
Abstract
Using a combination of continuous wave and time-resolved spectroscopy, we study the effects of interfacial conditions on the radiative lifetimes and photoluminescence intensities of sub-monolayer colloidal CdTe/CdS quantum dots (QDs) embedded in a three-dimensional porous silicon (PSi) scaffold. The PSi matrix was thermally oxidized under different conditions to change the interfacial oxide thickness. QDs embedded in a PSi matrix with ∼0.4 nm of interfacial oxide exhibited reduced photoluminescence intensity and nearly five times shorter radiative lifetimes (∼16 ns) compared to QDs immobilized within completely oxidized, porous silica (PSiO2) frameworks (∼78 ns). The exponential dependence of QD lifetime on interfacial oxide thickness in the PSi scaffolds suggests charge transfer plays an important role in the exciton dynamics.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Aug 10, 2015
- Source ID
- 10.1063/1.4928663
Entities
People
- Daniel M. Fleetwood
- Dmitry S. Koktysh
- Girija Gaur
- Robert A. Reed
- Robert A. Weller
- Sharon M Weiss
Organizations
- Defense Threat Reduction Agency
- National Science Foundation
- Vanderbilt University