HOT-PHONON EFFECTS ON ELECTRON RUNAWAY FROM GAAS QUANTUM WIRES

Nonequilibrium (hot) optical phonon effects on electron runaway from G aAs quantum wires embedded in AlGaAs have been investigated by Monte C arlo technique. We have simulated the carrier runaway kinetics in the 0 <E< 1000 V/cm electric-field range for a lattice temperature of 30 K . Due to optical phonon mode confinement by GaAs/AlGaAs heterointerfac es, the buildup of generated hot phonons is strongly pronounced in the quantum wires. Even at moderate electron concentrations and electric fields, the accumulation of these phonons may become significant and s ubstantially affect all transport properties in the structure. As a re sult of reduced hot electron cooling rates in the presence of nonequil ibrium optical phonons, the high-energy tail of the carrier distributi on function extends above the potential barriers at the quantum wire b oundaries. This may eventually lead to significant electron escape fro m the potential well, even at relatively low electric fields, what sig nificantly affects the performance of such nanoscale systems. (C) 1997 American Institute of Physics.