SiGeC Optoelectronic Devices
Abstract
The spectral responses of a series of heterojunction diodes of p-type Ge(1-y)C(y) On n-type Si (100) substrates were measured by Fourier transform infrared spectroscopy. Alloy layers 0.5 micrometers thick were grown by molecular beam epitaxy at a substrate temperature of 400 C and were doped p-type with different B concentrations. With increasing C content, the diode dark current decreased, and the optical absorption band edge shifted toward higher energy by 70 meV for 0.12 atomic % of C. The increase in energy was attributed to the composition dependence of the bandgap rather than to strain relaxation, because the GeC layers were nearly relaxed with the same strain. The photoresponsivity was 0.07 Amps/Watt at a wavelength of 1.55 micrometers, and 0.2 Amps/Watt at a wavelength of 1.3 micrometers. These measurements show that GeC photodetectors have good properties and reasonable response at technologically important near-infrared wavelengths and can be fabricated by heteroepitaxy for compatibility with Si integrated circuits.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 24, 2001
- Accession Number
- ADA388459
Entities
People
- J. Kolodzey
Organizations
- University of Delaware