Mathematical modelling of the conductivity in CZTiS-CZSnS as a function of synthesis temperature

• Published in: Journal of physics. Condensed matter Vol. 33; no. 19; pp. 195201 - 195214
• Main Authors: Mesa, M Patarroyo, Báez, Y T Castellanos, Cerón-Achicanoy, M A, Gómez-Cuaspud, J, Chaparro, W Aperador, López, E Vera
• Format: Journal Article
• Language: English
• Published: England IOP Publishing 26.04.2021
• Subjects: impedance; Nyquist; photovoltaics; Raman; impedance; Raman; Nyquist; photovoltaics
• ISSN: 0953-8984; 1361-648X
• DOI: 10.1088/1361-648X/abf198

The electrical behavior of photovoltaic materials related with Cu ZnTiS and Cu ZnSnS 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 ). 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 42 , 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 and 10 Ω  m in comparison with traditional mathematical models used for this purpose.