Polaronic effects due to quasi-confined optical phonons in wurtzite nitride nanowire in the presence of an electric field

• The effect of electric field on the Fröhlich polaron in wurtzite nanowire is studied.
• The phonon confinement effect on polarons is taken into account.
• The polaron self-energy and effective mass in nitride nanowire is calculated.

Considering the effect of an external electric field in wurtzite nitride cylindrical nanowire (NW), the polaron self-energy and effective mass due to the electron interaction with the quasi-confined optical phonons are studied theoretically by means of Lee–Low–Pines variational approach. The analytical expressions for the quasi-one-dimensional Fröhlich polaron self-energy and effective mass are obtained as functions of the wire radius and the strength of the electric field applied perpendicular to the wire axis. It is found that the main contribution to polaron basic parameters is from higher frequency optical phonon modes. The numerical results on the GaN material show that the polaron self-energy increases with the increase of the electric field and is more sensitive to the field when the wire radius is larger. It is also found that the polaron self-energy in GaN NWs is higher than that in zinc-blende GaAs-based cylindrical NWs.