Abstract
The recombination dynamics of excitons in deep-etched (Zn,Cd)Se/ZnSe and ZnSe/Zn(Se,S) quantum wires has been investigated by time-resolved photoluminescence spectroscopy. At K, the lifetime in ZnSe/Zn(Se,S) wires is reduced for decreasing wire width from about 130 ps in the two-dimensional reference to about 10 ps in the 60-nm-wide wires. The experimental data can be described with a surface recombination velocity of 5× cm/s at K. In contrast, the low-temperature exciton lifetime in (Zn,Cd)Se/ZnSe quantum wires does not vary significantly with wire width down to nm. This indicates at K a strong suppression of carrier loss at the wire sidewalls most likely due to exciton localization effects. From high-temperature data, where localization effects can be neglected, we conclude that the surface recombination velocity in (Zn,Cd)Se/ZnSe quantum wires is about two orders of magnitude smaller than in the ZnSe/Zn(Se,S) system.
- Received 13 September 1995
DOI:https://doi.org/10.1103/PhysRevB.53.R4233
©1996 American Physical Society