The electron effective mass at the bottom of the GaNAs conduction band

Abstract

We determined the electron effective mass, m*e, from the photoluminescence (PL) of GaNxAs1−x/GaAs single quantum wells. The energy of the interband optical transitions is analysed within the frame of the band anti-crossing model (BAC), which accounts for a highly nonparabolic nature of the GaNAs conduction band (CB). From the PL we found that m*e at the bottom of the CB in GaNxAs1−x/GaAs quantum wells (QWs) increases from 0.095m0 to 0.12m0 for x increasing from 0.009 to 0.04. We found that the BAC model for III-N-V QWs predicts a strong increase of m*e as a function of the electronic subband number. We analyse also m*e at the bottom of the bulk GaNAs CB using the linear-muffin-tin-orbital (LMTO) method adjusted by inclusion of external potentials to account properly for energy gaps. The effective mass dependence obtained from LMTO calculations reproduces the experimental results. The nature of the nitrogen related A1 symmetry state, which enters in the BAC model, and similarities of this state with the Ga dangling bond state are discussed.