  In this paper, we present a coupled carrier-photon model that accounts for
the time-domain interactions between carrier transport and light emission in
Gallium Nitride (GaN)-based LEDs that hasn't been reported so far. Carrier
transport is modeled using the drift-Diffusion formulation, whereas light
emission and propagation is modeled using Maxwell's equations. The drift
Diffusion equation is solved self-consistently with Poisson equation. The
carrier transport and photon emission are coupled by formulating an appropriate
relation between radiative recombinations and dipole sources such that the
strength of the dipole sources is given by the radiative recombination rates
gauged to an appropriate value. This gauging factor is obtained by calibrating
the External Quantum Efficiency (EQE) of homojunction GaN LED with the
experimental value.
