Hot-electron relaxation in semiconductor quantum wires: Bulk-LO-phonon emission

We calculate, within the electron-temperature model, the rate of energy loss due to bulk-LO-phonon emission from a hot-electron gas to a cold lattice in quasi-one-dimensional GaAs quantum-wire structures. Our theory includes the known important physical mechanisms, such as degeneracy, dynamical screening, quantum confinement, and the hot-phonon bottleneck effect. In the experimentally interesting electron-temperature range of 50–200 K, we find the hot-phonon effect to be quantitatively the most significant physical mechanism determining hot-electron energy relaxation. The typical intrasubband relaxation time is of the order of a picosecond, quite comparable to that found in two-dimensional quantum-well structures.