Exciton states in zinc-blende GaN/AlGaN quantum dot: Effects of electric field and hydrostatic pressure

Based on the effective-mass approximation, the effects of the electric field and hydrostatic pressure on exciton states in a cylindrical zinc-blende (ZB) GaN/AlGaN quantum dot (QD) are investigated variationally. Numerical results show that the electric field leads to a remarkable reduction of the ground-state exciton binding energy and interband transition energy in the case of any hydrostatic pressures. However, the hydrostatic pressure increases the exciton binding energy and interband transition energy in the case of any electric fields. In particular, the electric field has a remarkable influence on the exciton binding energy in the QD with large dot size and small hydrostatic pressure; moreover, the hydrostatic pressure obviously affects the exciton binding energy in the QD with small dot size and weak electric field.