PHOTOLUMINESCENCE OF GaAs/AlAs QUANTUM WELLS

An unusual emission - I line has been observed in the photoluminescence spectra of MBE GaAs/AlAs MQW at 4.2K. Its half width is 6.5-9meV with peak energy Located between the near band transition and the free electrons to carbon acceptors transition in bulk GaAs. The peak energy increases roughly linearly with the logarithm of the excitation power. The emission intensity decreases with the increase of temperature and disappears at about 15K.