Enhanced light emission from germanium microdisks on silicon by surface passivation through thermal oxidation

• Xuejun Xu

• Hideaki Hashimoto

• Kentarou Sawano

• Hiroshi Nohira

• Takuya Maruizumi

Abstract

We have observed enhanced direct-gap light emission from undoped and n-doped germanium microdisks on silicon. The enhancement is attributed mainly to increased carrier density due to surface passivation of the dry-etched sidewall. The enhancement factor increases as the disk size decreases, approaching 4 for microdisks with radii of 1 µm. To achieve maximum enhancement and not modify the geometric structure of resonators, 450–500 °C is found to be the best temperature window. Thermal oxidation is also effective for the degraded interface induced by sputtered Al 2 O 3 . These results indicate that thermal oxidation is a promising method suitable for fabrication of low-threshold germanium lasers.

Journal

• Applied Physics Express

  Applied Physics Express 9 (5), 052101-, 2016-03-30

  IOP Publishing

Keywords

• General Physics and Astronomy
• General Engineering

Details

• CRID: 1360847874814669184
• NII Article ID: 210000137877
• DOI: 10.7567/apex.9.052101
• ISSN: 18820786
• ISSN: 18820778
• Web Site: http://stacks.iop.org/1882-0786/9/i=5/a=052101/pdf
• Web Site: http://stacks.iop.org/1882-0786/9/i=5/a=052101?key=crossref.0c46c560007633cc885a5f304494a60a
• Web Site: https://iopscience.iop.org/article/10.7567/APEX.9.052101
• Web Site: https://iopscience.iop.org/article/10.7567/APEX.9.052101/pdf
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