Investigating the Suitability of Cu2ZnSnS4 Thin Films for Gamma Radiation Dosimetry Applications in Nonmedical Environments

Abstract

The need for the replacement of cadmium, indium, and tellurium in their compounds for sensor applications is a novel study. The copper zinc tin sulfide (Cu2ZnSnS4) thin films were synthesized from Cu (99.99%), Sn (99.99%), and Zn (99.99%) using the thermal evaporation method. The same volumetric parameters were maintained throughout the synthesis process. The films were further irradiated using an isotope of cesium-137 (Cs-137) from a gamma source at different doses (0–0.6 kGy) and dose rates of 0.1007 Gy/h at room temperature. Both the pristine (0 kGy) and irradiated (0.1, 0.3, and 0.6 kGy) films were characterized with a Raman spectroscope, a field emission scanning electron microscope (FESEM) with the JEOL JSM-7600F model, energy dispersive X-rays (EDX), an ultraviolet–visible–near infrared (UV–Vis–NIR) spectroscope, and four-point probe techniques. The Raman results confirmed that all the films for both pristine and irradiated films have a main and secondary phases. The EDX results showed that the pristine and 0.1 kGy films were Cu-rich films, while the 0.3 kGy and 0.6 kGy films turned out to be Zn-rich films with an increase in gamma radiation dose. The optical properties of all the films showed also that the band gap decreased from 1.6 to 1.48±0.03 eV for the pristine and irradiated films, while the electrical resistivity results decreased as the gamma radiation dose increased. However, as the structural, optical, and electrical properties of the Cu2ZnSnS4 thin films responded linearly with the increasing gamma radiation dose, this suggests the usefulness and possibility of designing a new solid-state sensor for dosimetry applications to replace cadmium telluride (CdTe) and copper indium gallium sulfide (CIGS) thin films.