IUVSTA 15th International Vacuum Congress (IVC-15), AVS 48th International Symposium (AVS-48), 11th International Conference on Solid Surfaces (ICSS-11)
    Photonics Materials Topical Conference Thursday Sessions
       Session PH-ThP

Paper PH-ThP1
Photoconductivity Perculiarities of @gamma@- Irradiated Silicon, Doped with Sulfur in Spectral Region 10,6 MCM

Thursday, November 1, 2001, 5:30 pm, Room 134/135

Session: Poster Session
Presenter: A.V Karimov, Academy of Sciences of Republic Uzbekistan
Authors: A.V Karimov, Academy of Sciences of Republic Uzbekistan
R.Sh. Avezov, Academy of Sciences of Republic Uzbekistan
V.T. Tulanov, National University of Uzbekistan named after M.Uilugbek, Uzbekistan
Correspondent: Click to Email
@gamma@-irradiation influence on Si < s > photoconductivity in spectral region 10,6 mcm was investigated. It was found that while compensation degree was increased both dark and light resistivities increased by 3-4 orders. Photoconductivity of sulfur doped silicon in the region of 10,6 mcm was investigated very poor. We know only one work,@footnote 1@ fulfilled under photoreciever cooling up to 5 K. The purpose of this paper is to investigate @gamma@-irradiation influence on Si photoconductivity under cooling up to liquid nitrogen temperature. It is known that under @gamma@ -irradiation of silicon a number of donor and acceptor levels are created in the gap.@footnote 2@ As donor levels are placed in the lower half of the gap and sulfur creates a number of donor levels in the upper part of the gap, they don’t reveal themselves in 10,6 mcm photoconductivity. Only acceptor levels have influence, decreasing the filling of donor levels created by sulfur and free electrons concentration in conductivity band. The samples were investigated with specific resistivity 80 @OMEGA@.cm., produced by sulfur diffusion into crucileless p-type silicon with initial specific resistance 1600 @OMEGA@.cm. Samples were of parallelogram form with dimensions 10 x 8 x 1 mm@super 3@. Two nickel contacts were drifted electrochemically on one side of greater area at 7mm apart from one another. As irradiation source there was used impulsive CO@sub 2@ laser LGI-50, that gives impulse of 150 mcs duration and 13 mJ energy. Direct voltage 10 V was applied to the sample. Dark current value and photoresponse were measured by memorizing oscillograph S8-12. As @gamma@-irradiation source there was used @super 60@Co, that created flux 1,7·10@super 12@ quanta/cm@super 2@·s. Kinetic equation for one level model (but with several values of energetic levels) was solved and it was established that no less than two energetic levels in semiconductor’s gap take part in 10,6 mcm photoconductivity. @FootnoteText@ @footnote 1@ N. Sclar. Infrared Physics. 1976, V.16, P.435 @footnote 2@ V.C. Vavilov, I.P. Kekelidze and L.S. Smirnov. Influence of radiations on the semiconductors. M. Nauka, 1988.