Origins of Midgap Electron Traps in Plastically Bent GaAs_1-xP_xTernary Alloys

Abstract

Electron traps in plastically bent VPE n-GaAs1-x P x (0≤x≤1) have been investigated using DLTS. While EL2 is dominant at x\lesssim0.5, two additional levels, one a midgap (EP1) and the other a deeper (EP2) level, dominate at x\gtrsim0.55. The energy level of EP1 at x=1.0 is in good agreement with that of the antisite PGa defect level in GaP estimated using ESR studies. EP2 energy levels have little dependence on x. EP1 as well as EL2 shows alloy broadening in DLTS spectra while EP2 remains unchanged. These findings indicate that EL2 and EP1 are due to antisite AsGa and PGa defects, respectively. EP2 is attributable to group V atom site defects.

New electron and hole traps in GaAsP alloy

“…Defects in semiconductors play a particularly important role in materials and device properties, causing a decrease in light emission efficiency and degradation in device performance, mainly due to the formation of non-radiative recombination centres which may lie deep in the energy gap (Forbes 1975, Lopez et al 1979, Hawkins and Forbes 1975, Calleja et al 1983, Kaniewska and Kaniewski 1988, Henning and Thomas 1982, Tokuda 1987, Zhang et al 1990, Kaminski 1993, Chino 1986, Samuelson and Omling 1986, Omling et al 1983.…”