Theory of some effects of photon recycling in semiconductors

Abstract

The effect of photon recycling (or self-excitation) in semiconductors is established theoretically for the minority carrier lifetime, the minority carrier diffusion coefficient and an electric field parameter, for a wide range of physical situations. These include absorption coefficients, reflection coefficients at the boundary of the semiconductor (and therefore the refractive indices), semiconductor layer thickness and internal quantum efficiency. The new features of this work are: the inclusion of the dependence on the incidence angle of the reflection coefficients, an improved but fairly simple derivation of the corrections to the observable quantities due to photon recycling, and the effect of photon recycling on the electric field. As already known, the most important effects are on the lifetime, whereas the diffusion coefficient is relatively insensitive to photon recycling. It is pointed out here that the effect can, however, be significant if the absorption length exceeds the diffusion length. In this case the effect on the electric field is also important and increases with the reflection coefficient.