Insulator passivation of In/sub 0.2/Ga/sub 0.8/As-GaAs surface quantum wells

The electronic passivation of (100) In/sub 0.2/Ga/sub 0.8/As-GaAs surface quantum wells (QWs) using in situ deposition of an amorphous, insulating Ga/sub 2/O/sub 3/ film has been investigated and compared to standard Al/sub 0.45/Ga/sub 0.55/As passivation. Nonradiative lifetimes /spl tau//sub r/=1.1/spl plusmn/0.2 and 1.2/spl plusmn/0.2 ns have been inferred from the dependence of the internal quantum efficiency /spl eta/ on optical excitation density P/sub 0/' for the Ga/sub 2/O/sub 3/ and Al/sub 0.45/Ga/sub 0.55/As passivated In/sub 0.02/Ga/sub 0.8/As-GaAs surface QW, respectively. Beyond identical internal quantum efficiency, the amorphous Ga/sub 2/O/sub 3/ insulator passivation simplifies device processing, eludes problems arising from lattice-mismatched interfaces, and virtually eliminates band bending in electronic and optoelectronic devices based on a low dimensional system such as quantum wells, wires, and dots.