Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7932471 | Optics Communications | 2013 | 7 Pages |
Abstract
In this paper, we report on the spectral dependence of În=noâne for CdGa2S4 single crystals for shorter and longer wavelengths than the isotropic wavelength λ0=485.7 nm (300 K). It was established that În is positive at λ>λ0 and it is negative in the spectral range λ<λ0. The isotropic wavelength λ0 exhibits blue spectral shift with temperature decreasing. The ground and excited states of three excitonic series A, B and C with binding energies of 53 meV, 52 meV and 46 meV, respectively, were found out at 10 K. The effective masses of electrons for k=0 were derived from the calculation of excitonic spectra: mcâ¥(Ðâ¥Ñ)=0.21m0 and mcâ¥(Ðâ¥Ñ)=0.19m0. The holes masses are equal to 0.59m0 and 0.71m0 for Ðâ¥Ñ and Ðâ¥Ñ, respectively. The value of valence bands splitting, V1âV2, by crystalline field equals 24 meV, and V2âV3 splitting due to the spin-orbital interaction equals to 130 meV. The optical functions n, k, ε1 and ε2 for Ðâ¥Ñ and Ðâ¥Ñ polarizations were calculated by means of Kramers-Kronig analyses in the energy interval 3-6 eV. The evidenced features are discussed taking into account the results of new theoretical calculations of CdGa2S4 band structure.
Related Topics
Physical Sciences and Engineering
Materials Science
Electronic, Optical and Magnetic Materials
Authors
I.G. Stamov, N.N. Syrbu, V.I. Parvan, V.V. Zalamai, I.M. Tiginyanu,