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HAIT Journal of Science and Engineering Volume 1, Issue 2, pp. 266-273 © 2004 Holon Academic Institute of Technology | ||||||
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Fermi level pinning and long-term relaxation effects in doped IV-VI narrow-gap semiconductors
Dmitriy Khokhlov1,* and Boris Volkov2
1Physics Department, Moscow State University, Moscow 117234, Russia
| 2P.N. Lebedev Physics Institute, Russian Academy of Sciences, Leninskii pr. 53, Moscow 117924, Russia *Corresponding author: khokhlov@mig.phys.msu.su Received 2 December 2003, accepted 5 March 2004
| Starting from mid-70's, a great deal of both experimental and theoretical efforts has been attracted to the unexplained puzzle of impurity states arising in IV-VI narrow-gap cubic semiconductors doped with some of the group III elements, and to unusual effects observed in these materials. We review the experimental results obtained in the field: mixed valence phenomena, electrical activity of impurity centers, persistent photoconductivity and related effects. Some of the features of these semiconductors have provided the possibility of construction far-infrared photodetectors with extremely high characteristics. The theoretical models proposed so far to account for the physical picture of the processes involved, are discussed.
___________________ | Presented at Russian-Israeli Conference Frontiers in Condensed Matter Physics Shoresh, Israel, 19-24 October 2003 |