A photoluminescence study of beryllium-doped GaAs grown by molecular beam epitaxy

Abstract

The 300-K photoluminescence internal quantum efficiency of beryllium-doped GaAs grown by molecular beam epitaxy at 580 °C from As4 under arsenic stable conditions is limited by nonradiative recombination with τNR = 3.5 to 5.6×10−10 s. τNR remains in this range while 1.3×1015 < NA−ND < 8×1017 cm−3. Layers grown at fixed NA−ND = 3×1016 cm−3 and constant thickness exhibited a 140-fold increase in internal efficiency as the growth temperature was raised from 480 to 660 °C. The corresponding internal efficiencies were calculated to be 0.054%, ⩾ 0.69%, and ⩾ 7.6%, respectively. The 6.5-K photoluminescence spectra of layers grown at 580, 620, and 660 °C showed no significant differences and exhibited none of the new bound exciton lines reported by Kunzel and Ploog to be present in molecular beam epitaxial GaAs grown from As4 below 610 °C.