Binding energies of bound polaron in a wurtzite nitride nanowire: Contributions of IO and QC phonon modes

Abstract

AbstractBy employing the two‐parameter variational approach, the binding energies of bound polarons in a quasi‐one‐dimensional wurtzite nanowire (NW) are investigated. Two types of polar optical phonon modes, i.e., the interface optical (IO) and quasi‐confined (QC) phonon modes of wurtzite NWs are taken in account. The results reveal that the phonon contribution to binding energy of bound polaron in GaN NWs reaches ∼370 meV. The quite large contribution of phonon modes to the total binding energy is mainly ascribed to the very strong electron–phonon coupling constant in GaN materials. Moreover, the IO modes plays more important role to the binding energies of bound polaron as the NW radius is small, while the QC modes dominates as the NW radius is relatively large. The calculated results of impurity binding energy are quite consistent with the recent experimental measurement. The numerical results also show that the two‐parameter variational approach is necessary and suitable for the description of impurity states in wurtzite GaN NW structures.