Thiol-amine co-solvents aided direct synthesis of ZnTe thin films by spin coating for low cost optoelectronic applications

Zinc telluride (ZnTe) thin films have special semiconducting characteristics that make them very promising for a broad range of optoelectronic applications. In this work, a novel approach for synthesizing ZnTe thin films by spin coating technique is followed using a unique solution process with ZnTe directly dissolving in thiol-amine co-solvents. Thin films are synthesized on glass substrates and air annealed at 250–350 °C. The polycrystalline phase of ZnTe is revealed through the X-ray diffraction (XRD) study. The scanning electron microscopy (SEM) is used to observe the surface smoothness of the films. Moreover, elemental compositions of ZnTe thin film have been determined by energy dispersive spectroscopy (EDS) study. FTIR spectroscopy reveals that ZnTe has been successfully synthesized as confirmed by the characteristic peaks in the spectrum of 554–1000 cm −1 . The optical transmittance of the films increases with annealing temperature as investigated using UV–vis spectroscopy. Furthermore, the optical bandgaps of the films of 2.92 eV, 2.84 eV, and 2.5 eV have been found at 250 °C, 300 °C, and 350 °C annealing temperatures, respectively. These results suggest that controlling the annealing environment serves as a valuable strategy for tailoring the ZnTe film properties to meet specific application requirements. Utilizing the properties of ZnTe, an AgAuS photodetector has been designed and analyzed. The result exhibits an outstanding V OC of 0.92 volt, photocurrent of 35.16 mA/cm 2 , responsivity of 0.66 AW −1 , and detectivity of 9.52 × 10 15 Jones. These results reveal that spin coated ZnTe thin films are attractive ones for various applications in optoelectronic devices such as solar cells and photodetectors. • ZnTe thin films have been deposited by spin coating using thiol-amine co-solvents. • Deposited ZnTe thin films are polycrystalline as confirmed by XRD. • Optical bandgap of the ZnTe films varies in the range of 2.5–2.92 eV. • AgAuS photodetector (PD) has been designed and analyzed with the properties of ZnTe. • The findings indicate the potential of spin coated ZnTe in optoelectronic devices.