NORMAL-INCIDENCE STRAINED-LAYER SUPERLATTICE GE0.5SI0.5/SI PHOTODIODES NEAR 1.3 MU-M

Ge0.5Si0.5 strained-layer pin photodiodes, in which multiple strained layers serve as the absorption region, have been fabricated. These devices exhibit an optical response at wavelengths beyond 1.3 mu m at normal incidence. The measured external quantum efficiencies at an applied bias of 4 V are 17% at 0.85 mu m and 1% at 1.3 mu m, respectively. Excellent electrical characteristics evidenced by the avalanche breakdown at 20 V have also been demonstrated. (C) 1995 American Institute of Physics.