Effects of electric field and hydrostatic pressure on the exciton states in strained zinc-blende In[formula omitted]Ga[formula omitted]N-GaN coupled double quantum wells

Abstract

Based on the effective mass approximation, the variational theory study of the exciton properties in a strained zinc blende GaN/InxGa1−xN/GaN/InyGa1−yN/GaN coupled double quantum well is presented considering the combined effects of hydrostatic pressure, strain, and external electric field. The results show that the exciton binding energy first increases, it achieves a maximum value, and then decreases with the reduction of the well width. Contrarily, the exciton binding energy decreases slightly first, it reaches a minimum value, and then increase gradually until a constant with the enhancement of the middle barrier thickness. Meantime, the pronounced dependencies of the exciton binding energy, interband transition energy, emission wavelength, oscillator strength, and radiation decay time of the coupled double quantum well on hydrostatic pressure are analyzed systematically. As the hydrostatic pressure increases, the exciton binding energy increases linearly, and the interband transition energy (emission wavelength) is proportional (inversely) to hydrostatic pressure. In addition, the variation of the exciton binding energy and Stark shift with the external electric field is explored detailedly.