Donor and acceptor energies for muonium in GaAs

Abstract

Analysis of existing data on muonium in GaAs provides an extensive set of ionization energies and barriers for motion and site transitions. Within an accepted model of muonium behavior in III-V compounds, these results establish the energy relationships among observed muonium centers in GaAs, including the metastable states. This analysis places the (0/+) donor level at $0.17\phantom{\rule{0.3em}{0ex}}\mathrm{eV}$ below the conduction band edge and the (\ensuremath{-}/0) acceptor level at roughly $0.60\phantom{\rule{0.3em}{0ex}}\mathrm{eV}$ above the top of the valence band for this very light hydrogen isotope, thus locating the muonium equivalent of the H(+/\ensuremath{-}) pinning level about $0.21\phantom{\rule{0.3em}{0ex}}\mathrm{eV}$ above midgap in GaAs, nearly $0.5\phantom{\rule{0.3em}{0ex}}\mathrm{eV}$ higher than predicted.