Influence of pressure on donor bound exciton states in wurtzite InGaN/GaN quantum dot nanowire heterostructures

The effects of hydrostatic pressure and strong built-in electric field on the donor bound exciton states confined in wurtzite InxGa1-xN/GaN strained quantum dot (QD) nanowire heterostructures (NWHETs) are investigated using a variational method under the effective mass and simplified coherent potential approximations. The results show that the hydrostatic pressure has a significant influence on the bound exciton states and interband optical transitions. The bound exciton binding energy almost linearly increases if the hydrostatic pressure increases. The emission wavelength has a blue-shift if the hydrostatic pressure increases and a red-shift if the QD height increases. The bound exciton binding energy more obviously depends on the hydrostatic pressure for the small radius or the large height QDs. The hydrostatic pressure can effectively enhance the exciton oscillator strength and improve the light emission efficiency of InxGa1-xN/GaN QD NWHETs.