DEVICE-QUALITY SUBMICRON ARRAYS OF STACKED SIDEWALL QUANTUM WIRES ON PATTERNED GAAS (311)A SUBSTRATES

Three-dimensional arrays of vertically stacked sidewall quantum wires ate fabricated by molecular beam epitaxy on GaAs (311)A substrates pat terned with 500-nm-pitch gratings. The cathodoluminescence spectra at low temperature are dominated by the emission from the quantum wires w ith narrow linewidth accompanied by a very weak emission from the conn ecting thin quantum wells due to localization of excitons at random in terface fluctuations. When the carriers in the quantum well become del ocalized at elevated temperature, only the strung emission fi om the q uantum-wire array is observed revealing perfect carrier capture into t he quantum wires without detectable thermal repopulation of the quantu m well up to room temperature. Thus, unpreceded device quality of this quantum-wire structure is demonstrated. (C) 1998 American Institute o f Physics.