Inelastic phonon scattering in long-range-ordered (Al0.5Ga0.5)(0.5)In0.5P - art. no. 125210

Carrier relaxation and recombination in long-range-ordered (Al0.5Ga0.5)(0.5 )In0.5P have been studied by selectively excited photoluminescence (PL) spe ctroscopy. We observed sharp resonant PL peaks under near-resonant excitati on. The set of resonant PL peaks evolves according to excitation energy. Th e excess excitation energies for the resonant PL peaks agree well with the LO-phonon energies related to the Ln-P, Ga-P, and Al-P bonds of the ordered sample. Furthermore, the LA resonance caused by zone-folding effects was o bserved. These resonant PL intensities show different excitation energy dep endence, which precludes the possibility of resonant Raman scattering. High dense excitation reveals an excited state near the X level. This suggests mixing of electron wave functions in the Gamma and X states. Energy relaxat ion of excited carriers from the pseudodirect X state to the Gamma ground s late causes the resonant FL. Time-resolved spectroscopy was employed to stu dy the carrier relaxation mechanism.