Figure 1
From: Study of the heavily p-type doping of cubic GaN with Mg
(a) Calculated hole mobility as a function of doping concentration in cubic GaN considering both phonons scattering and ionized impurities (IonImp) scattering. The temperature is set at T = 300 K. The intrinsic phonon limited mobility, hole effective mass is also listed in the figure. (b) The calculated defect formation energy of Mg substitution for Ga as a function of Fermi energy. The zero of Fermi energy is aligned to the valence band edge. A negative Fermi energy means hole degenerate doping condition while Fermi level above conduction band edge means the electron degenerate doping condition. The ionization energy corresponds to the transition level ε(0/− 1) which is about 99.6 meV above the VBM. Two conditions, i.e., N-rich and Ga-rich, are considered. The practical growth condition will fall in between these two extremes. An illustration of the atomic structure of Mg-doped cubic GaN is inserted in the figure.
