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The electrical behavior of photovoltaic materials related with Cu2ZnTiS4 and Cu2ZnSnS4 materials were analyzed as function of synthesis temperature in accordance with a new mathematical model based on the Kramers–Kronig equations with a high reliability. The samples were obtained through a hydrothermal route and a subsequent thermal treatment of solids at 550 °C for 1 h under nitrogen flow (50 ml min−1). The characterization was done by x-ray diffraction, ultraviolet spectroscopy (UV), Raman spectroscopy, atomic force microscopy (AFM) and solid state impedance spectroscopy (IS) techniques. The structural characterization, confirm the obtention of a tetragonal material with spatial group I-42m, oriented along (1 1 2) facet, with nanometric crystal sizes (5–6 nm). The AFM and Raman analysis confirm a high level of chemical homogeneity and correlation with the synthesis temperature, associated with the roughness of the samples. The UV spectroscopy confirm a band gap around 1.4–1.5 eV, evidencing the effectiveness of the synthesis process. The IS results at room temperature with a probability of 95%, confirm a high consistency of data with respect to values of real and imaginary impedance, allowing to obtain information of the conductance, reactance and inductance, achieving conductivity values around 10−5 and 10−3 Ω−1 m−1 in comparison with traditional mathematical models used for this purpose.

Study on the conductivity of the material Cu2ZnTiS4 (CZTiS), obtained under a hydrothermal route from precursor nitrates treated in a teflon reactor under constant pressure with a stainless steel jacket, involving different heat treatments (200, 225, 250, 275 and 300°C) for reaction times of 48 hours in all cases and subsequent calcination at 550°C in a tube oven, under nitrogen flow (50 mL min-1). The materials were characterized by X-ray Diffraction (XRD), Raman spectroscopy, Scanning Electron Microscopy (SEM), and Atomic Force Microscopy (AFM). The results showed materials with structural and crystalline properties concordant with a kesterite type phase, evidencing homogeneous surfaces, unique morphological properties derived from the process with regular distribution of particles and size of the nanometric order (5-6 nm) as well as the characteristics of the roughness of the material. Solid state impedance spectroscopy (IS) evidenced its electrical behavior and validated the proposed mathematical models.

The current work reports the synthesis and characterization of a photovoltaic material based on the CuIn1−xGaXSe2(X = 0.3 y 0.5) system, making use of the doctor blade method. For this purpose, homogeneous inks were obtained and worked under previous stoichiometry arrangement. The deposition process of thin films, were made in a heating plate on conventional glass substrates, previously washed and treated for this purpose. Once the layers of Cu, In, and Ga were deposited by chemical bath, a thermal treatment was performed at 550 °C for 30 min in a conditioned oven, in which the selenization process was performed. The obtained films were characterized by X-ray diffraction, Raman spectroscopy, solid-state impedance spectroscopy, UV spectroscopy and scanning electron microscopy techniques. The identification of the main crystalline phase could be corroborated, as well as the conductive and optoelectronic behavior of the solids in accordance with reported in literature. Simultaneously, it was checked that the method used allows obtaining layers of an optimum thickness, in order to be used as an absorbent layer in the design of solar devices.