InGaN height-controlled quantum dots (HCQDs) were grown by alternately depositing In0.4Ga0.6N QD and In0.1Ga0.9N spacer layers on a seed In0.4Ga0.6N QD layer. Structural and optical studies showed that the height of the InGaN QDs was controlled by the deposition cycle of In0.4Ga0.6N/In0.1Ga0.9N layers. Photoluminescence studies showed that the In0.4Ga0.6N HCQDs provided deep potential wells and the piezoelectric field-induced quantum-confined Stark effect was negligibly small. These phenomena are attributed to variation in quantum confinement energy in the electronically coupled InGaN HCQDs providing deep potential wells. (C) 2010 Elsevier B.V. All rights reserved.