| Original Articles |
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Fabrication of Ge Nano-Dot Heterojunction Phototransistors for Improved Light Detection at 1.55μm |
| SHI Wen-Hua;MAO Rong-Wei;ZHAO Lei;LUO Li-Ping;WANG Qi-Ming |
| State Key Laboratory on Integrated Optoelectronics, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083 |
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| Cite this article: |
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SHI Wen-Hua, MAO Rong-Wei, ZHAO Lei et al 2006 Chin. Phys. Lett. 23 735-737 |
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Abstract Heterojunction phototransistors (HPTs) with several Ge/Si nano-dot layers as the absorption region are fabricated to obtain improved light detectivity at 1.55μm. The HPT detectors are of n-p-n type with ten layers of Ge(8ML)/Si(45nm) incorporated in the base-collector junction and are grown by an ultrahigh-vacuum chemical-vapor-deposition system. The detectors are operated with normal incidence. Because of the good quality of the grown material and fabrication process, the dark current is only 0.71pA/μm2 under 5V bias and the breakdown voltage is over 20V. Compared to the positive-intrinsic-negative (PIN) reference detector with the same absorption layer, the responsivity is improved over 17 times for normal incidence at 1.55μm.
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| Keywords:
85.60.Dw
81.05.Hd
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Published: 01 March 2006
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| PACS: |
85.60.Dw
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(Photodiodes; phototransistors; photoresistors)
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81.05.Hd
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(Other semiconductors)
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