| 摘要 |
PROBLEM TO BE SOLVED: To lower the threshold value by employing InGa AIN set at a specified composition in a barrier layer of a quantum well structure. SOLUTION: A barrier layer of multiple quantum well structure has composition shown by Inx Ga1-x-y Aly N (0<x<0.5, Y<0.8x+0.05). When In composition x exceeds 0.5 in the composition InGaAlN of the barrier layer, laser oscillation cannot take place. When it is not lower than Al 10.5, resistance is increased significantly through a laser element. The relation represents the boundary between these defective growth conditions and high quality growth conditions. Even when the InGaN is added with a small quantity of Al to produce a mixed crystal, the well becomes sufficiently deep on the conduction band side, as compared with valence band side and light electrons can contribute to oscillation without casing overflow thus lowering the threshold value. |
