Exciton states and optical transitions in InGaN/GaN quantum dot nanowire heterostructures: Strong built-in electric field and dielectric mismatch effects

► The built-in electric field reduces the effective band gap of quantum dots. ► The built-in electric field leads to a remarkable electron-hole spatial separation. ► Dielectric mismatch obviously influences on exciton states and optical transitions. ► Radiative decay time increases exponentially when quantum dot height increases.