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Based on the effective mass approximation, the variational theory study of the exciton properties in a strained zinc blende GaN/In x Ga 1 − x N/GaN/In y Ga 1 − y N/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. [ABSTRACT FROM AUTHOR]

Within the effective mass approximation, we studied the light-hole and heavy-hole exciton states and their optical properties, such as oscillator strength and radiative decay time, in asymmetric zinc-blende GaN/In x Ga 1 − x N/GaN/In y Ga 1 − y N/GaN coupled double quantum wells. The variational method was performed under strain and hydrostatic pressure. The light-hole and heavy-hole exciton binding energies as a function of the left-well width and/or right-well width, middle-barrier thickness, and indium concentration x (y) of (In,Ga)N material are analyzed in detail. The light-hole and heavy-hole exciton binding energies show an increasing trend with increase of hydrostatic pressure. The hydrostatic pressure not only results in an increase in exciton binding energy, interband transition energy, and oscillator strength but also a decrease in the emission wavelength and radiative decay time. In addition, the biaxial strain dependence of the emission wavelength, radiative decay time, and interband transition energy of the exciton is very remarkable. • The exciton states in zinc-blende InGaN–GaN coupled double quantum wells are studied. • The exciton properties for light holes and heavy holes in the structure are analyzed. • The variational method was performed under strain and hydrostatic pressure. • The ground-state exciton binding energies are computed under hydrostatic pressure. • The interband transition energy and emission wavelength are investigated detailedly. • The exciton oscillator strength and radiative decay time are studied systematacially. [ABSTRACT FROM AUTHOR]