How much better are InGaN/GaN nanodisks than quantum wells - oscillator strength enhancement and changes in optical properties

摘要

We show over 100-fold enhancement of the exciton oscillator strength as thediameter of an InGaN nanodisk in a GaN nanopillar is reduced from a fewmicrometers to less than 40 nm, corresponding to the quantum dot limit. Theenhancement results from significant strain relaxation in nanodisks less than100 nm in diameter. Meanwhile, the radiative decay rate is only improved by 10folds due to strong reduction of the local density of photon states in smallnanodisks. Further increase in the radiative decay rate can be achieved byengineering the local density of photon states, such as adding a dielectriccoating.