Two-dimensional electron gas at Ga0.5In0.5P/GaAs heterointerface spontaneously induced by atomic ordering

Photoluminescence (PL) study for the long-range ordered Ga0.5In0.5P/GaAs heterointerface was performed to investigate effects of a spontaneous electron accumulation on the GaAs-PL spectrum. In contrast to sharp GaAs-signals from the disordered sample, a broad PL spectrum was observed for the ordered sample. A new structure ascribed to the Fermi edge was found at the higher-energy side of the fundamental GaAs-PL peak. From PL-excitation results, we suggest that a two-dimensional electron gas in a triangular potential is induced at the ordered Ga0.5In0.5P/GaAs heterointerface. Furthermore, magneto-PL results indicate that quantized levels in the triangular potential at the heterointerface interact with the Fermi surface.