Direct Observation of Phonons Generated During Nonradiative Capture in GaAs p−n Junctions

Phonon generation by GaAs epilayers and p-n junctions is studied by means of a superconducting bolometer and time-of-flight techniques. The polarization of the emitted radiation is found to be sensitive to doping in agreement with theoretical selection rules. The relative strength of the radiative and nonradiative processes is shown to depend on defect density and bias and demonstrates the energy transfer processes in p-n junctions.