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. (c) 2005 Elsevier B.V. All rights reserved.