Theoretical studies on light emission characteristics of high-efficiency BInGaN/GaN quantum well structures with blue spectral range

Light emission characteristics of blue B_xIn_yGa_1-x-y N/GaN quantum well (QW) structures were using the multiband effective-mass theory. The In composition (y) to give the transition wavelength of 440 nm is reduced with the inclusion of the B composition (x). We find that the spontaneous emission peak rapidly increases with increasing x. In particular, the peak intensity of the BInGaN/GaN QW structure with x = 0.18 and y = 0.008 is about twice larger than that of the conventional InGaN/GaN QW structure. This can be explained by the fact that the internal field (-0.40 MV/cm) in the BInGaN well is In greatly reduced, compared to that (-1.04 MV/cm) in the conventional InGaN well. Also, the strain (-1.7%) in the BInGaN well is shown to be reduced slightly, compare to that (-2.0%) in InGaN well. Hence, we expect that BInGaN/GaN QW structures with a reduced strain can be used as a light source with a high efficiency.