We have developed a new class of sensitive infrared photodetectors based on the group III - doped IV-VI semiconductors. 

Recent Results

There are several types of photodetectors available that are based on different physical principles:

• Operating wavelength > 100 µm.
  Operating temperature (4.2 - 15) K.
  Detector area slices up to 20 mm in diameter.
  Operating rate up to 100 kHz.
  Current responsivity (at 3 Hz operating rate) 10⁹ A/W NEP 2*10^-16 W
  (defined by sensitivity of measuring equipment, operating rate 3 Hz, detector area 0.3*0.2 mm²)
  
  

• Operating wavelength (3-5.5) µm.
  Operating temperature (60 - 160) K.
  Operating rate up to 10 kHz.
  Realization of the BLIP regime.
  
  
• Operating wavelength > 500 µm.
  Operating temperature (60 - 70) K.
  Operating rate up to 10 kHz.
  
  

The characteristic features of these materials providing high photodetector parameters are the following:

1. Extremely high spatial homogeneity and time stability of the photodetectors, absolute reproducibility of the basic material properties.
   
2. Realization of a semiinsulating state of material at low temperatures; - possibility of tuning of the photogenerated electron lifetime in wide range (10^-5-10⁴) s by means of temperature and alloy composition variation.
   
3. Possibility of fast quenching (for 10^-5 s) of accumulated photosignal in the persistent photoconductivity regime, when the electron lifetime is high (up to 10⁴ s); - quantum efficiency of the photodetector may be increased up to ( 10² in some special regime of the persistent photoconductivity quenching.
   
4. Extremely high stability with respect to the action of hard radiation (dozes up to 10¹⁷ cm^-2, it is at least by 4 orders of magnitude higher than for ordinary photodetectors).
   
5. Spatial stability of the infrared image: the photoexcited free electrons do not diffuse out of the region of generation; - well developed technology of both bulk and epitaxial growth of materials.
   
   

Relative key publications:

1. S.N.Chesnokov, D.E.Dolzhenko, I.I.Ivanchik, D.R.Khokhlov. Far infrared high-performance lead telluride-based photodetectors for space-born applications. Infrared Phys., 35 23 (1994).

2. B.A.Akimov, N.B.Brandt, L.I.Ryabova, D.R.Khokhlov. A new type of material with high photosensitivity for optoelectronics and infrared technology. J. Advanced Mater., 1 13 (1994).

3. B.A.Akimov, D.R.Khokhlov. Lead telluride-based photodetectors: a new approach. Semicond. Sci. Technol., 8 S349 (1993).

Contact person:Dmitriy Khokhlov