Eur. Phys. J. B 72, 67-75 (2009)
https://doi.org/10.1140/epjb/e2009-00332-y

Optical properties of III-nitrides in electric fields

¹ Núcleo de Pesquisa em Física, Departamento de Física, Universidade Católica de Goiás, 74605-010 Goiânia Goiás, Brazil
² Condensed Matter Physics Department, Institute of Physics “Gleb Wataghin”, University of Campinas-Unicamp, 13083-970, Campinas, SP, Brazil

Corresponding author: ^a cloves@ucg.br

Received: 19 April 2009
Revised: 23 August 2009
Published online: 10 October 2009

Abstract

The influence of intermediate to high electric fields on the optical properties of direct-gap strongly-polar III-Nitrides is characterized. It is manifested through the dependence on the electric field of the nonequilibrium thermodynamic state of the system, which is characterized by a nonequilibrium effective temperature (quasi-temperature), quasi-chemical potentials and drift velocities of the excited carriers driven away from equilibrium, and the quasi-temperatures of the phonons in the different branches. In particular, we analyze the processes of absorption and luminescence, and a field-dependent Roosbroeck-Shockley relation is derived. It is shown that it is possible to measure the carriers' drift velocity and quasi-temperature, in the steady state or with ultrafast time resolution, resorting to luminescence together with Raman scattering experiments.