RECOMBINATION IN DEEP ETCHED CDZNSE ZNZE QUANTUM WIRES/

Picosecond photoluminescence spectroscopy was used to investigate the recombination dynamics of excitons in deep etched CdZnSe/ZnSe quantum wires with lateral extensions down to 20 nm. In the low-temperature re gime (T less than or equal to 10 K), no significant reduction of the e xciton lifetime was found down to a wire width of 20 nm, indicating a negligible influence of carrier loss at the wire sidewalls. At higher temperatures, the lifetime decreases for decreasing wire width, e.g., from 330 ps in the mesa structure to 21 ps in the 28 nm wide wires at room temperature. Simple model calculations indicate that this drop of the lifetime is due to diffusive carrier transport to the wire sidewa lls and subsequent non-radiative surface recombination.