Effect of hydrostatic pressure on optical absorption spectrum AlGaN/GaN multi-quantum wells

The current paper investigates the optical absorption spectrum of Al_0.3 Ga_0.7 N/GaN multi-quantum well (MQW) under hydrostatic pressure. To obtain the parameters of Al_0.3 Ga_0.7 N/GaN MQW, such as electron and hole density, bandgap, interband transition energy, electron-hole wave functions, effective mass and dielectric constant, and the hydrostatic pressure effects are taken into account. Finite difference techniques have been used to acquire energy eigenvalues and their corresponding eigenfunctions of Al_0.3 Ga_0.7 N/GaN MQW and the hole eigenstates are calculated via a 6 × 6 k.pmethod under an applied hydrostatic pressure. It was found that the depth of the quantum wells, bandgaps, band offset, the electron, and hole density increases with the hydrostatic pressure. Also, as the pressure increases, the electron and hole wave functions will have less overlap, the amplitude of the absorption coefficient increases, and the binding energy of the excitons decreases. A change in pressure of up to 10 GPa causes the absorption coefficients peaks of light and heavy holes to shift to low wavelengths of up to 32 nm. Keywords