FABRICATION AND OPTICAL CHARACTERIZATION OF WET CHEMICALLY ETCHED CDTE CDMGTE WIRES/

We have fabricated optically active semiconductor wires based on CdTe/ CdMgTe quantum well structures by electron beam lithography and wet ch emical etching. Wire widths between 5 and 40 nm have been achieved. Th e wires have been characterized by photoluminescence spectroscopy. Dow n to about 300 nm, no significant decrease of the photoluminescence in tensity is observed at 5 K. In narrower wires, free excitons can diffu se to the open wire surface and recombine nonradiatively thereby causi ng a reduction of the quantum efficiency. Increasing the temperature u p to 100 K causes a larger diffusion length of free excitons which lea ds to a reduction of the quantum efficiency in small wires. Bound exci tons, which cannot diffuse towards the wire surface, show significantl y higher luminescence efficiency in narrow wires compared to free exci tons.