Studies Of Preparation And Properties Of In₂S₃ Thin Films By Magnetron Sputtering

I112S3, which belongs to III-VI compound semiconductor, has been widely studied for their unique optical, electrical and photoelectric properties. ln2S3 thin films fabricated through chemical methods presents several drawbacks, including poor crystalline quality, composition deviation from stoichiometry, and exist of secondary phase. Up to now, there are few reports about In2S3 thin films prepared by magnetron sputtering technique.In this thesis, In2S3 thin films have been prepared through magnetron sputtering process. Effect of sputtering parameters such as sputtering power, substrate temperature, thickness, working pressure and seed layer on the phase structure, composition, morphology, transmittance, band gap and photoconductivity of the films have been studied. The obtained results reveal that:1. As the sputtering power is larger than 80W, the component of the deposited films show near stoichiometry feature. Band gap of the film is 2.45 eV, exhibiting relatively good transmittance and higher dark current density.2. Increasing substrate temperature leads to improvement of film crystallite. Thin Film deposited at 380℃ show stoichiometry with dense granular grain structure.3. With the increase of film thickness, the sputtered In2S3 films exhibit a slightly sulfur deficient feature and a tetragonal phase. Change of surface morphology, Raman vibration bands and optical transmittance are observed. Transmittance and optical band gaps occur "red shift". Photoconductivity properties of the films were related to rate competition among photo-generation, recombination and trapping of carriers.4. As the sputtering pressure increased from 0.1 Pa to 1.0 Pa, the dominant phase of the sputtered films transfers from tetragonal to cubic. Crystallization of the thin improved and the optical band gap became larger. Transmittance occur "blue shift", when the sputtering pressure increased.5. By previously depositing a seed layer of cubic phase In2S3, induce growth of the subsequent film was observed as the films deposited between 0.1 Pa-0.5Pa film. Seed layer induced|3-In2S3 films exhibit uniform properties of cubic phase, grain size, surface morphology, and optical performance. Seed layer induced growth reduces the structure and properties deviation of the fabricated films as the sputtering parameters varied. Compared to the single-layer films, induced grown In2S3 films show improvement in crystallinity, optical transmittance, and band gap width.