Stability Of The Composite Semiconductor （C₄H₉-C₅H₄）₂N₂I₂ Under High Pressure And Exploration Of A Novel Crystallization Route

Currently, the poor thermal and chemical stability of the organic-inorganic composite semiconductor materials are barriers to the crystal growth and the fabrication of thin film devices. In this work, the stability of the composite semiconductors had been greatly improved by applying high pressure method. Furthermore, the structure and electrical transport properties of the composite semiconductor polycrystalline prepared by high pressure method had been studied. Then, we explored a novel isostatic-pressure crystallization route and investigated the growth of large size composite semiconductor single crystals. The main contents are as follows:1. The thesis take 1,1’-dibuty-4,4’-bipyridinium diiodide as object of study, attempt to investigate the influence of high pressure on composite semiconductors during the heating process. It had been found that the thermal stability of 1,1’-dibuty-4,4’-bipyridinium diiodide was strikingly improved when the pressure exceeded 100 MPa. Besides, polycrystalline ceramics were fabricated by hot-pressure method and the morphology and structure were analyzed.2. A series of I-V curves were obtained under 48-288 MPa isostatic-pressure with the designed in-situ testing platform of electrical transport properties. By analyzing the changes of electrical transport properties, we found that the resistance of the material increased as the pressure increasing. Besides, the response of the material to pressure varied with the change in temperature.3. An isostatic-pressure crystallization route was proposed in order to obtain the large size composite semiconductor single crystals. By applying high isostatic-pressure, the composite semiconductor single crystal with the size larger than 400 μm was obtained when ethanol was introduced, which makes it a potential candidate for fabricating single crystal devices.