Synthesis and Characterization of Nanostructured Copper Zinc Tin Sulphide (CZTS) for Humidity Sensing Applications

Copper zinc tin sulphide (CZTS) microsphere comprising thin nano sheets with high porosity and the wide surface area was developed via the surfactant-assisted hydrothermal method and was further characterized using XRD, FESEM, and TEM revealing its crystalline nature, efficient morphology, and internal structural, respectively. The band gap of CZTS is found to be 1.8 eV owing minimum crystallite size and the average crystallite size of 13 and 34 nm, respectively. The absorption analysis of CZTS was done using UV-Vis, FTIR, and Raman spectroscopy. Finally, the humidity sensing capability of the material was enquired using both the electrical and optical modes. Electrical mode gave an excellent sensitivity of 10.77 MΩ/%RH with the fast response and recovery times of 7.4 and 57 s, respectively, whereas optical mode gave a sensitivity of ~1.051 μW/%RH with the response and recovery times of 46 and 80 s, respectively.