Transient response in doped germanium photoconductors under very low background operation
Abstract
Doped germanium photoconductors are the most sensitive detectors for astronomy in the wavelength range 40–240 μm. Under the extremely low background conditions encountered in cooled satellite instruments, these devices exhibit a number of transient effects, such as slow relaxation after a step change in illumination or bias, and spontaneous spiking at high signal levels. Such behavior can degrade the excellent instantaneous sensitivity of these detectors and create calibration uncertainties. These effects have been observed in the Ge:Be photoconductors and the stressed and unstressed Ge:Ga photoconductors in the Long Wavelength Spectrometer, one of the instruments on the Infrared Space Observatory. A systematic investigation of the transient response of the Long Wavelength Spectrometer detectors to a step change in illumination as a function of operating temperature, bias electric field, and illumination step size has been carried out to determine operating conditions that minimize the effects of this behavior. The transient effects appear to be due primarily to carrier sweep out, but they are not fully explained by existing models for transient response.
Additional Information
© Copyright 1996 Optical Society of America. Received 9 August 1995; revised manuscript received 18 October 1995. This research was supported by Science and Engineering Research Council grant SGC24450. M. Price acknowledges receipt of a Science and Engineering Research Council studentship.Files
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Additional details
- Eprint ID
- 10732
- Resolver ID
- CaltechAUTHORS:CHUao96
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2008-06-05Created from EPrint's datestamp field
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2020-03-09Created from EPrint's last_modified field