Effects of spontaneous polarization on optical properties of ultraviolet BAlGaN/AlN quantum well structures

Effects of spontaneous polarization on electronic and optical properties of ultraviolet (UV) B _x Al _y Ga _1-x-y N/AlN quantum well (QW) structures were using the multiband effective-mass theory. The spontaneous emission peak begins to decrease when the boron composition exceeds a critical value. The critical value is found to increase rapidly with decreasing the absolute value of the spontaneous polarization constant. In addition, the light intensity is reduced with decreasing spontaneous polarization. However, the spontaneous emission peak of BAlGaN/AlN QW structures is found to be greatly improved with the inclusion of the boron, irrespective of the spontaneous polarization. Hence, we expect that BAlGaN/AlN QW structures can be used as a high-efficiency light source for optoelectronic applications in ultraviolet spectral region.