Mitsubishi Cable Industries, Ltd.

Takayuki Hashimoto

Hiroaki Okagawa

Kazuyuki Tadatomo

Keiji Miyashita

Tomoo Yamada

Shinichi Watabe

A semiconductor light emitting element comprising an n-type semiconductor substrate and a light emitting part comprising an n-type cladding layer composed of an InGaAlP compound semiconductor material, an active layer and a p-type cladding layer formed in that order from the substrate side by double heterojunction, wherein said semiconductor light emitting element satisfies at least one of the following conditions:

Semiconductor light emitting element with In GaAlP active layer of

In the light emitting element comprising an n-type semiconductor substrate, a lower electrode formed on the lower surface of the substrate, and a light emitting part having a pn junction, which is composed of an InGaAlP compound semiconductor material, a p-type current diffusing layer and an upper electrode which are laminated on the upper surface of the substrate in that order from the substrate side, the improvement wherein a carrier concentration of the current diffusing layer is lower on a light emitting part side thereof than that on an upper electrode side thereof, and at least the upper electrode side of the current diffusing layer is composed of GaP. By employing such structure, diffusion of the dopant to a light emitting part can be suppressed even when the carrier concentration of the upper part of the current diffusing layer is set to be higher, thereby affording a lower resistance of the current diffusing layer as a whole. The GaP being a compound semiconductor without Al, the amount of the dopant necessary for affording the superior effects of suppressing the diffusion of the dopant to the light emitting part can be less. Consequently, the luminous efficiency can be improved as compared with conventional ones, and a light emitting element having a long service life and superior reliability can be obtained.

Semiconductor light emitting element with a current diffusing layer

A semiconductor light emitting element comprising a light emitting part comprising an AlGaInP active layer and a AlGaInP cladding layer, which is formed on a GaAs substrate, and an AlGaAs layer and a Ga.sub.x In.sub.1-x P layer (0.7.ltoreq.x.ltoreq.1.0) deposited in this order on said light emitting part, wherein said Ga.sub.x In.sub.1-x P layer has a thickness of not more than 1.0 .mu.m. According to the present invention, absorption of the emitted light by an electrode contact layer and the occurrence of an interfacial distortion between the electrode contact layer and the layer thereunder can be suppressed, and a semiconductor light emitting element permitting easy production thereof and having a high luminance and a long service life can be provided.

Growing community of inventors

Kuga-gun, Japan

Takayuki Hashimoto