Optical and photoelectric properties of anisotropic semiconductors
Members of the group
Spectra of optical absorption, photoconductivity and short-circuit photocurrent
are known to be very informative for investigations of the peculiarities of the
band structure. However the studies on these spectra for CdAs2 and
ZnAs2 anisotropic crystals are very limited.
Using the mentioned methods CdAs2 crystals were studied in a
polarized light over the temperature range of 77-300 K, and two indirect and
one direct interband optical transitions were observed. The energies of
effective phonons, bonding energies of indirect excitons, and the temperature
dependence of energy gap were determined.
The investigations of ZnAs2 crystals with very low residual impurity
concentration have unambiguously shown that the first absorption edge in
ZnAs2 is determined by indirect optical transitions. The excitonic
absorption peak associated with direct interband transitions was observed in
the 77-300 K temperature range. This observation was possible due to high
structural perfection and purity of the studied crystals.
- V.A. Morozova, D.I. Pishchikov, S.M. Loseva, O.G. Koshelev and S.F.
Marenkin. Optical and photoelectric properties of ZnAs2 single
crystals. Fiz. i Techn. Poluprovodn. 25, 1664 (1991) (in Russian).
- V.A. Morozova, S.F. Marenkin, T.V. Semenenya, A.M. Raukhman, S.M. Loseva
and O.G. Koshelev. Optical and photoelectric properties of CdAs2
single crystals. Neorg. Mater. 30, 33 (1994) (in Russian).
- V.A. Morozova, T.V. Semenenya, S.M. Loseva, O.G. Koshelev, S.F. Marenkin,
A.M. Raukhman. Determination of CdAs2 band structure parameters
from optical transmission and photoconductivity. Semiconductors 29,
- V.A. Morozova, T.V. Semenenya, S.F. Marenkin, O.G. Koshelev, A.M. Raukhman,
S.M. Loseva. Optical transitions in perfect undoped CdAs2 single
crystals at the edge of fundamental absorption and in the range of impurity
absorption. Inorganic Materials 32, 10 (1996).
Physics of Semiconductors division