Shallow-donor impurity states in type-II InGaN-ZnSnN2/GaN quantum wells under hydrostatic pressure effect

Taking into account the built-in electric field (BEF) effect, shallow-donor impurity (SDI) states in a strained type-II InGaN-ZnSnN₂/GaN quantum well (QW) are investigated variationally under hydrostatic pressure. Numerical results reveal that the SDI binding energy and BEF strengths of different well and barrier layers depend on hydrostatic pressure and structural parameters of the type-II QW. The BEF strengths in left and right wells, middle barrier, and barriers on both sides are proportional to the hydrostatic pressure. Meantime, the BEF strengths in well and/or middle barrier layers (barriers on both sides) decrease (increase) linearly with increasing the width of the well and/or middle barrier layers (barriers on both sides). The binding energy displays a maximum value as the well width decreases, and it increases linearly (decreases gradually) with the increment in hydrostatic pressure (middle barrier thickness). Moreover, the position of an impurity ion has a significant impact on the SDI binding energy. It is hoped that the obtained results will be helpful in improving the physical performance of tunable type-II InGaN-ZnSnN₂/GaN quantum wells (QWs) optical devices.