NEAR-FIELD OPTICAL SPECTROSCOPY OF CARRIER EXCHANGE BETWEEN QUANTUM-WELLS AND SINGLE GAAS QUANTUM WIRES

Real-space transfer and trapping of carriers into single GaAs quantum wires on patterned (311)A GaAs surfaces are studied by near-field lumi nescence and luminescence excitation spectroscopy with a spatial resol ution of 250 nm at temperatures of 8 and 300 K. At room temperature, r eal-space transfer of carriers in continuum states occurs over a lengt h of several micrometers determined by the mobility of holes and the n anosecond carrier lifetimes. At low temperature, local energetic barri ers in the vicinity of the sire suppress the capture process.