Mitsubishi Monsanto Chemical Co., Ltd.

Mitsubishi Chemical Industries Limited

Mitsubishi Kasei Corporation

Toshio Ishiwatari

Hisanori Fujita

Tadashige Sato

Yasuji Kohashi

A double hetero type epitaxial wafer contains a single crystal substrate, first and second conductivity type clad layers which are opposite and are made of mixed crystal compounds of Group III-V which had an indirect transition type band structure, and an active layer made of a mixed crystal compound of Group III-V which has a direct transition type band structure and is interposed between the respective clad layers, wherein the first conductivity type clad layer has a refractive index smaller than that of the second conductivity type clad layer.

Double hetero type epitaxial wafer with refractive indices

The reproducibility of Te doping in III-V group compounds is improved by using as the dopant a III-V group compound containing Te at a concentration of at least 1.times.10.sup.17 cm.sup.-3.

Growing community of inventors

Abiko, Japan

Toshio Ishiwatari