PHOTOLUMINESCENCE OF A STAGGERED IN0.5GA0.5P/ALXGA1-XAS HETEROJUNCTION

Photoluminescence of the In0.5Ga0.5P/AlxGa1-xAs heterojunction with Al mole fractions x = 0.29 and x = 0.19 is presented. Below-band-gap photoluminescence with a peak energy less than both band gap energies of the constituent materials was observed. As the laser excitation intensity was decreased, the peak energy of the luminescence shifted to the lower energy side and showed a saturation behavior. The full width at half maximum of the peak also decreased as the laser excitation intensity was decreased. These phenomena indicate that the heterojunction has a staggered band alignment at each value of the Al mole fractions. The expected band alignment of the heterojunction at various Al mole fractions is presented.