Microscopic origin of the phenomenological equilibrium "Doping limit Rule" in n-type III-V semiconductors
The highest equilibrium free-carrier doping concentration possible in a given material is limited by the "pinning energy" which shows a remarkable universal alignment in each class of semiconductors. Our first-principles total energy calculations reveal that equilibrium n-type doping is ultimately limited by the spontaneous formation of close-shell acceptor defects: the (3-)-charged cation vacancy in AlN, GaN, InP, and GaAs and the (1-)-charged DX center in AlAs, AlP, and GaP. This explains the alignment of the pinning energies and predicts the maximum equilibrium doping levels in different materials.
Zhang
SB
National Renewable Energy Laboratory, Golden, Colorado 80401, USA.
Wei
S
Zunger
A