Codoping of p-type GaN with Mg and oxygen was investigated. By codoping with oxygen the hole concentrations increased to 2 × 1018 cm-3 at 295 K, an order of magnitude greater than in Mg-doped epilayers. The resistivity of codoped layers decreased from 8 to 0.2 Ω cm upon oxygen codoping. Variable temperature Hall effect measurements indicated that the acceptor activation energy decreases from 170±5 meV in Mg-doped films to 135 ±5 meV upon oxygen doping. The higher hole concentration results in part from a decrease in the ionisation energy of the acceptor.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)