Abstract

A theory of carrier transport in highly nanostructured optoelectronic devices cannot be entirely formulated without addressing the coupling of the current-carrying extended states to the localized states of the system, and the interaction of such localized carriers with coherent fields, as obtained from the classical solution of the Maxwell's equations, or with incoherent field fluctuations, if spontaneous emission is of interest. We will illustrate this complex interplay between carrier transport and optical transitions for a specific class of light-emitting devices, but similar considerations also apply to the inverse regime of light detection and photovoltaics, as a consequence of the principle of detailed balance, which links emission of light by radiative recombination to light absorption by generation of electron–hole pairs, leading e.g., to reciprocity relations between the photovoltaic and the electroluminescent properties of solar cells and light-emitting diodes (LEDs) [1]. For illustrative purposes, we will focus on spatially resolved approaches to describe the far-above threshold, possibly multimode, lasing regime of vertical cavity surface emitting lasers (VCSELs). We will not discuss lumped models based on rate equations for spatially integrated carrier and photon densities, being these approaches restricted to the near-threshold dynamic behavior of single-mode lasers.