Strain-tunable carrier mobility of Fe-doped GaN: A first-principles study

Using first-principles calculations together with acoustic deformation potential scattering theory, we have investigated the strain-tunable carrier mobility of Fe-doped GaN with a doping concentration of 3.125%. Our calculated results show that the electron mobility of Fe-doped GaN decreases with increasing compressive strain but increases with increasing tensile strain. Unlike that electron mobility, the hole mobility monotonically decreases as the compressive stress increases. The hole mobility reaches its maximum value in the ground state structure. From the calculated phonon dispersion we verified that the dynamic stability of Fe-doped GaN can be maintained in the strain range of ±1.5%. We also found that the tensile strain can effectively improve carrier mobility of Fe-doped GaN, especially for the electron mobility. The excellent electronic properties of Fe-doped GaN could have possible applications in photoconductive switches and optoelectronic devices.