Effect of Nitrogen‐Induced Modification of the Conduction Band Structure on Electron Transport in GaAsN Alloys

We report pressure studies of conductivity, photoconductivity and Hall effect in Si doped GaAs0.986N0.014. We observed that pressure causes an unusually large reduction of the electron mobility in this compound (factor of 2.5 in the pressure range 0 to 2 GPa). We also measured the pressure coefficient of the energy gap and we found it, in agreement with previous reports, to be reduced by almost 40% compared to that of GaAs. These results can be successfully explained by a recently proposed, phenomenological model based on the concept of an anticrossing interaction between localized N-related states (resonant with the conduction band) and conduction band states. This model explains well the reduction of the pressure coefficient of the bandgap and predicts an enhancement of the effective mass of GaAs1—xNx. The decrease of electron mobility observed in the present study is in agreement with this latter prediction.