Special subject: 510403 Physics of condensed matter
Program: 20 Spectroscopy of solid state
Program manager: prof. B. V. Novikov
Solid state physics department
Scientific adviser: docent A. Yu. Serov
Reviewer: 

Shallow bound exciton in CuGaSe2 crystal
V. L. Bogdanov

In low temperature (5K-40K) photoluminescence spectra of CuGaSe2 crystal the line of shallow bound exciton at energy of 1.713 eV was observed. The shape and temperature dependence of the line indicate that bound exciton interacts with pseudo-local vibration. The form of photoluminescence spectra from different points of crystal is different.
Theoretical spectra were calculated, but good agreement with experimental curves was achieved only for point of the best quality of the crystal. One can indirectly judge the quality of the crystal by the form of free-exciton line (1.723 eV).
By results of the work following conclusions can be made:
1.	Stokes shift increases with deterioration of quality of crystal.
2.	In points of high damping there is additional structure at energy of 1.708 eV, which decreases fast with growing of temperature. This structure is probably bound exciton too.
3.	There is anti-stokes component of bound exciton in photoluminescence spectra of CuGaSe2 crystal.

The list of the publications
1. V. Bogdanov. Low temperature luminescence of bound exciton in CuGaSe2 crystal//  Conference abstracts International Student Conference "Science and Progress" - SPb.: SOLO, 2010, p. 76.
2.