Semiconductor light emitting device including a hole barrier contiguous

Abstract

In a semiconductor light emitting device comprising an active layer, a hole barrier layer is formed in contact with a first surface of the active layer to provide a barrier against holes in the active layer. The barrier layer does not provide a barrier against electrons tunnelling therethrough. A low energy band gap layer is formed on the barrier layer to have a conduction band minimum which is lower than the conduction band minimum of the active layer at least in a part adjacent to the barrier layer. First and second electrodes are in ohmic contact with an n-type and a p-type conductivity layers which are formed on the low energy band gap layer and a second surface of the active layer, respectively. Preferably, the p-type conductivity layer comprises an electron barrier layer on the second surface, a waveguide layer formed on the electron barrier layer to have an energy band gap wider than an energy band gap of the active layer, and a remaining layer formed between the waveguide layer and the second electrode to have an energy band gap wider than the emergy band gap of the waveguide layer. The waveguide layer may be removable without losing high speed capability of the laser.