Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1531347 | Materials Science and Engineering: B | 2008 | 4 Pages |
Abstract
A Si/SiGe HBT-type phototransistor with 10 Ge-dot layers (8ML in each layer, separated by 30 nm Si spacer) incorporated in the base-collector junction was grown by UHV-CVD. To achieve low dark current density and high photo-responsivity, a high-low emitter profile consisting of a heavily doped polysilicon contact on top of a thin epitaxial emitter cap has been fabricated. At room temperature, I-V measurement showed a low dark current density of 3 Ã 10â5 A/cm2 at 3 V. The measured breakdown voltage BVceo was about 12 V. A photo-responsivity of 1.94 and 0.028 mA/W was achieved at 1.31 and 1.55 μm for normal incidence, respectively. Compared to a p-i-n reference detector with the same quantum-dot layer, the responsivity is improved by a factor of 45 and 20 at 1.31 and 1.55 μm, respectively.
Related Topics
Physical Sciences and Engineering
Materials Science
Electronic, Optical and Magnetic Materials
Authors
Rongshan Wei, Ning Deng, Hao Dong, Min Ren, Lei Zhang, Peiyi Chen, Litian Liu,