Built-in electric field effect in wurtzite InGaN/GaN coupled quantum dots

Based on the effective mass approximation, the built-in electric field effect on exciton states confined in wurtzite InGaN/GaN coupled quantum dots (QDs) is investigated by means of a variational approach. We find that the strong built-in electric field in the wurtzite InGaN/GaN coupled QDs gives rise to a marked reduction of the effective band gap of InGaN QDs. The exciton binding energy is reduced monotonically as the barrier thickness between the two coupled wurtzite InGaN QDs is increased.