HETEROJUNCTION DEVICES.
Abstract
The opto-electric characteristics of abrupt Ge-GaAs heterojunctions have been investigated to determine if such devices are efficient photon detectors. Because of a notch in the band edge at the interface the quantum efficiency is low. Further, such a device as the collector in an optical transistor is concluded to be impractical. A method of determining the minority carrier lifetime in the Ge adjacent to the GaAs, from the photocurrent spectrum, is developed. Near the band gap of Ge, the photocurrent spectrum exhibits changes in slope attributable to the onset of phonon assisted absorption. An efficient photodetector is described which utilizes a Ge-Si n-n heterojunction. A qualitative theory for this is developed. Photo-excited holes are trapped in the notch in the valence band which in turn modulates the diode current. Attempts to fabricate a wide band gap transistor have been unsuccessful. It was determined that a poor injection efficiency resulting from a predominance of recombination current in the GaAs is at fault. An apparatus for probing semiconductor devices is described. The thermoelectric and photovoltaic methods are used. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 01, 1965
- Accession Number
- AD0614676
Entities
People
- Donald E. Boyce
- G. Zeidenbergs
- J. Rock
- R. L. Anderson
- S. Yawata
Organizations
- Syracuse University