Light Emitters Based On Germanium Tin Alloys
Abstract
With a direct energy bandgap and compatibility with commercial circuit processing, germanium-tin semiconductors are attractive for high performance, integrated optoelectronics at middle-infrared wavelengths. Using molecular beam epitaxy and Clean Room processing, GeSn optoelectronic devices were fabricated, and measured to determine their characteristics and limitations. By reducing the substrate temperature to100C during growth, the epitaxy was optimized to achieve an unusually high Sn content of 31 atomic %. A variety of substrate wafers were used, including silicon, germanium, and gallium arsenide. The GeSn layers had excellent crystal structure as measured by x-ray diffraction, with smooth surfaces as measured by atomic force microscopy. Novel doping sources were studied, including boron and gallium acceptors for p-type doping, and arsenic and phosphorus donors for n-type doping. The fabricated optoelectronic devices included p-n junctions, heterojunctions, and photoconductors, which had excellent electrical and optical properties, measured using infrared spectroscopy. These results showed that GeSn alloys are suitable for device applications in the field of infrared silicon photonics.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 31, 2017
- Accession Number
- AD1057164
Entities
People
- J. Kolodzey
Organizations
- University of Delaware