A p-Ge/sub 1-x/C/sub x//n-Si heterojunction diode grown by molecular beam epitaxy

We report on the fabrication and characterization of the first p-n diode made from a heterojunction of epitaxial p-type Ge/sub 0.998/C/sub 0.002/ on an n-type Si substrate. Epitaxial Ge/sub 0.998/C/sub 0.002/ was grown on a (100) Si substrate by solid source molecular beam epitaxy. The p-GeC/n-Si junction exhibits diode rectification. The I-V characteristics of the p-GeC/n-Si diode indicate a reasonable reverse saturation current of 89 pA/μm
²
at -1 V and a high reverse breakdown voltage in excess of -40 V. Photoresponse from the Ge/sub 0.998/C/sub 0.002/ p-n diode was observed from 1.3-μm laser excitation resulting in an external quantum efficiency of 1.4%.