The Effect of the Number of Precursor Spin-Coating on the Properties of Sb<sub>2</sub>(S,Se)<sub>3</sub> Thin Film

Preparing of Sb 2 S 3 precursor by sol gel method and the post selenization is a simple and low-cost method for preparing Sb 2 (S, Se) 3 . In the preparation process of this method, the number of spin-coating of Sb 2 S 3 precursor determines the film thickness, structure, and S/Se ratio. In this work, the effects of different spin-coating times (1 to 5) on the structure, optical and electrical properties of the film were studied. The results showed that when the number of spin-coating increased from 1 to 5, the thickness of the film increased from 0.24 μm to 1.17 μm. When spin-coating twice, the strongest diffraction peak of the film changed from (120) to (230); as the spin-coating frequency continued to increase, the film gradually exhibited Sb 2 S 3 characteristics, accompanied by a small amount of Sb 2 O 3 impurities. In addition, excessive spin-coating cycles can cause large voids to appear on the surface of the film. From the UV-visible spectrum, it can be seen that as the thickness of the film increases, the light absorption also gradually improve, and the band gap increases from 1.34 eV to 1.66 eV. The Mott-Schottky test showed that the prepared thin films were all P-type semiconductor. When spin-coated twice, the carrier concentration of the thin film reached 5.8×10 15 cm -3 .