Article contents
Pbte(Ga) - New Multispectral Infrared Photodetector
Published online by Cambridge University Press: 10 February 2011
Abstract
Doping of the lead telluride - narrow-gap semiconductor - with gallium results under certain conditions in the Fermi level pinning in the gap thus providing the semiinsulating state of material. Besides that, the persistent photoconductivity effect is observed at a temperatures T < Tc = 80 K. The photoresponse kinetics consists of two parts: the slow one with the characteristic time tchar going up to 104 s at T = 4.2 K, and the fast part with tchar, of the order of 10 ms. We have measured the spectra of a fast part of the photoresponse using the Fouriertransform spectrometer “Bruker” IFS- 113v. The photoconductivity is observed in two spectral regions: in the middle- and far - infrared. Response in the middle-infrared consists of the ordinary fundamental band and a strong superimposed resonance-like structure just at the bandgap energy. The position of this spectral line may be tuned in a wide range (3.5–5.5) μm by variation of temperature and/or composition of a lead telluride-based alloy. This middle-infrared photoresponse becomes considerable already at T = 160 K. The photoresponse in the far-infrared may be depending on the excitation conditions an analogous resonance-like structure at a wavelength 70 μm, or a broad band with the cutoff wavelength at least higher than 500 μm, which is the highest cutoff wavelength for the photon detectors observed up to date.
- Type
- Research Article
- Information
- Copyright
- Copyright © Materials Research Society 1998
References
- 1
- Cited by