Optoelectronic Properties of Nanocolumn InGaN/GaN LEDs

In this work, we use the multiscale software tool TiberCAD to study the electronic and optical properties of InGaN-quantum-disk (QD)-based GaN nanocolumn p-i-n diode structures. Strain maps show a clear relaxation effect close to the column boundaries; however, results from full self-consistent 3-D quantum calculations indicate that emission is focused in the center of the QD and emission energy is little depending on the column size. Moreover, the effect of surface states on transport is largely reduced when quantum densities are taken into account, since current in the nanocolumn light emitting diode (LED) results to flow mainly in the QD region. Nanocolumn geometry appears to be quite robust against variation of lateral scale, while it is largely sensitive to the QD alloy composition.