Light-emitting element having nitride semiconductor multiquantum barrier, and process for production thereof

摘要

An Al0.95Ga0.05N:Mg (25 nm) single electron barrier can stop electrons having energy levels lower than the barrier height. Meanwhile, a 5-layer Al0.95Ga0.05N (4 nm)/Al0.77Ga0.23N (2 nm) MQB has quantum-mechanical effects so as to stop electrons having energy levels higher than the barrier height. Thus, electrons having energy levels higher than the barrier height can be blocked by making use of multiquantum MQB effects upon electrons. The present inventors found that the use of an MQB allows blocking of electrons having higher energy levels than those blocked using an SQB. In particular, for InAlGaN-based ultraviolet elements, AlGaN having the composition similar to that of AlN is used; however, it is difficult to realize a barrier having the barrier height exceeding that of AlN. Therefore, MQB effects are very important. Accordingly, it becomes possible to provide element technology for further improving deep UV light emission intensity using, as a light-emitting layer material, an AlGaInN-based material and, in particular, an AlGaN-based material.

主权项

1. A nitride semiconductor light-emitting element that emits light at a wavelength of 220 to 390 nm, comprising:
an AlxGa1-xN (0x2, y1y2) valley layers for the same number of periods or a 1st number of periods and a 2nd number of periods that differs from the 1st number of periods; and wherein the number of periods increases or decreases in a stepwise manner from the quantum-well light-emitting layer side to the multiquantum-barrier electron-blocking layer side.