<title>Effects of carrier diffusion on thermal properties of proton-implanted top-surface-emitting lasers</title>

Abstract

A comprehensive, 3D, thermal-electrical self-consistent finite-element model is described and used to investigate thermal properties of GaAs-AlGaAs proton-implanted top-surface-emitting lasers. Special attention is paid to carrier diffusion within the layer containing the active region and to its influence on temperature profiles. In the model, an analytical approximation is used to describe the 3D current spreading between the annular top contact and the broad- area bottom contact. Temperature dependence of many device and material parameters is included. Multiple heat sources are taken into consideration. The carrier diffusion equation, including injection-current generation, ambipolar diffusion as well as bimolecular and spontaneous recombination terms, is solved numerically using the finite-element method for the layer containing the active region. The results indicate that carrier diffusion strongly influences the distribution of main heat sources. As a result, both current-spreading and heat- spreading phenomena are modified.