Radiative Efficiency Enhancement in Blue Saw-Like InGaN/GaN Light-Emitting Diodes

Abstract

Light emission characteristics of saw-like blue InGaN/GaN quantum well (QW) light-emitting diodes (LEDs) are theoretically investigated using the multiband effective mass theory. The saw-like QW structure has several advantages such as the enhancement in light emission, the reduction in the quantum Stark effect, and the increase in the internal efficiency, compared with a conventional InGaN/GaN QW structure. The increase in the spontaneous emission peak of the saw-like QW structure is mainly attributed to the fact that the electron wavefunction is shifted toward the left side with the inclusion of the saw-like layer while the hole wavefunction is nearly invariant. The internal efficiency of the saw-like QW structure is shown to be much larger than that of a conventional QW structure. Hence, we expect that this structure can be used as high-efficiency blue InGaN/GaN LEDs.