Effects of hydrogen on the electronic properties of dilute GaAsN alloys.
Nitrogen has profound effects on the electronic structure of GaAs, as only a few percent of N can drastically lower the band gap. It is, however, not recognized that the same amount of N can also qualitatively alter the electronic behavior of hydrogen: First-principles calculations reveal that, in GaAsN, a H atom bonds to N and can act as a donor in its own right, whereas in GaAs and GaN, H is amphoteric, causing passivation instead. At high Fermi energy and H concentration, a N complex with two H was found to have lower energy than the single-H configuration. By removing the effect of N, this electrically inactive complex restores the gap of GaAs.
Janotti
A
A
National Renewable Energy Laboratory, Golden, Colorado 80401.
Zhang
S B
SB
Wei
Su-Huai
SH
Van de Walle
C G
CG