Papers by Author: Yang Ren

Abstract: Fluorine doped tin oxide (FTO) film is one of the most promising transparent conducting materials. It can be used for Low-E glasses, thin film solar cells, displays, etc. FTO film can be fabricated by various techniques. The technique of sol-gel combined with ultrasonic spray pyrolysis gives the possibility to produce high-quality large-scale FTO films. In this paper, the FTO sol is successfully prepared using pentahydrate stannic chloride (SnCl₄•5H₂O), hydrogen fluoride (HF) and methanol. Using the FTO sol, FTO films are prepared by ultrasonic spray pyrolysis technique. X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and atomic force microscopy (AFM) are used to characterize the FTO films coated on glass substrates. Results indicate that the as-deposited films are polycrystalline SnO₂ phase with tetragonal crystal structure, and that the average grain size for the samples is 160nm. The optical and electrical properties of the FTO film are also analyzed.

Abstract: Amorphous SiO2 thin films were fabricated at different temperatures using sol-gel technique. The unipolar resistive switching behavior was observed in Cu/ SiO2/ ATO (SnO2: Sb) sandwiched structure when the SiO2 thin film annealed at 500°C. The average ratio of Roff /Ron is 102. We investigated the successful device using HRTEM and XPS. It shows that the Cu defuses into the SiO2 thin film and it forms CuSiO3 in the interface between SiO2 and ATO films according to the high resolution images.

Abstract: SnO2:F transparent conductive thin films with the area of 500×500mm2 were deposited on glass substrates by spray pyrolysis using SnCl4•5H2O and HF as the starting material and dopant respectively in methanol. The effects of HF concentration on the crystallized status, microstructures, transmittance, conductivity and low emissivity performances of the films have been studied. The results indicated that when HF content was excessive the solution presented strong acidity and it was difficult to obtain the uniform and dense films. However, when HF content was less, the conductivity of the film was poor. In this paper, The optimal mount of dopant HF was investigated and the molar ratio of Sn to F is 1:0.5. And also the uniform and dense SnO2:F transparent conductive oxide thin films can be obtained, whose resistivity reached 6.36×10-4Ω•cm, and the average transmittance in visible region was 80%.The low emissivity of this film was 0.25, which could be used as the Low-E glass.

Abstract: In this paper, fluorine & antimony-doped tin oxide (FATO) transparent conductive thin films are deposited by Spray Pyrolysis on glass substrate, and low emissivity properties achieved. The emissivity of glass in far infrared region is optimized by changing the spray volume, the resistivity and sheet resistance of thin films. Research shows that the resistivity of thin films has important influence on infrared reflectance and hemispheric emissivity. This paper further investigates the quantitative relationship between emissivity and resistivity of low-E glass and also provides a basis for emissivity control and performance evaluation of Low-E glass.