Analysis of the optical properties of Cu(In(1-x)Ga(x))(3)Se(5) crystals

作者：Leon M^*; Serna R; Levcenko S; Gurieva G; Merino J M; Friedrich E J; Arushanov E

来源：Journal of Applied Physics, 2008, 104(9): 093507.

DOI：10.1063/1.2986159

Analysis of the optical properties of bulk Cu(In(1-x)Ga(x))(3)Se(5) mixed crystals synthesized from the elements as a function of the Ga content is presented. Measurements of the complex dielectric function epsilon(omega)=epsilon(1)(omega)+i epsilon(2)(omega) were performed at room temperature in the photon energy range of 0.8-4.7 eV using a variable angle of incidence ellipsometer. The spectral dependence of the complex refractive index, the absorption coefficient, and the normal-incidence reflectivity were also derived. The structure observed in the dielectric functions attributed to the interband transitions E(0), E(1A), and E(1B) has been modeled using a modification of the Adachi's model. The results are in excellent agreement with the experimental data over the entire range of photon energies. The model parameters, including the energies corresponding to the lowest direct gap and higher critical points, have been determined using the simulated annealing algorithm. The values of E(0) and E(1A) are found to increase linearly with the increasing Ga content.

• 出版日期2008-11-1