Preparation of Semiconductor Superlattice Film by Hydro-thermal Photoelectrochemical Method

本研究采用电沉积法和光电化学沉积法制备了高性能的无机材料，取得了以下成果。在高压电解槽中，在高于100ﾟC的高温下进行电沉积，并将稀土离子Sm和La插入到层结构中，虽然没有观察到外延生长，但得到了CoOOH等钴氧化物薄膜。在光照条件下，观察了二氧化铅和氧化铁在二氧化钛单晶电极上的光电化学外延生长。PEEG中的晶体取向取决于沉积的氧化物和衬底之间的晶体失配，晶体沿晶体失配最小的方向生长。晶体生长模型已在PEEG中得到验证。在该模型中，如果在电解过程中进行照明，则覆盖在电极整个表面的氧化膜。另一方面，薄膜部分覆盖了电极表面，但在脉冲照明的情况下，晶体大量生长。AEM测量证实了这一点，因此，在电极表面的某些部分，OH自由基的产生是平稳的，而在其他部分，则是缓慢的。在PbO_2沉积的多晶二氧化钛电极上观察到较大的隧道电流，而在单晶二氧化钛电极上观察到较大的隧穿电流。提出了原电极的费米能级钉扎模型。该电极作为工业阳极材料具有很好的应用前景。

In this research, the clectrodeposition and photoelectrochemical deposition have been carried out to prepare high performance inorganic materials, and the following results were obtained. The cobalt oxide film such as CoOOH was obtained using autoclave electrolysis cell where the electrodeposition was done under higher temperatures higher than 100ﾟC, and the rear earth ions such as Sm and La were intercalated into the layer structure, although epitaxial growth was not observed. The photoelectrochemical epitaxial growth (PEEG) was observed for the electrodeposition of lead dioxide and ferric oxide on a single crystal titanium dioxide electrode under illumination. The crystal orientation in the PEEG depended on the crystal mismatch between the deposited oxide and the substrate, and the crystal grew in the direction of the smallest crystal mismatch. The crystal growth model has been demonstrated in the PEEG.In this model, the oxide film covered on the entire surface of the electrode if the illumination is done during the electrolysis. On the other hand, the film partly covered the electrode surface, but the crystal grew largely in the case of the pulse illumination. This was proved by AEM measurement Consequently, OH radical will be produced smoothly at some parts of the electrode surface but slowly at other parts. The large tunneling current was observed at the PbO_2 deposited polycrystalline TiO_2 electrode, but was not at the single crystal TiO_2, electrode. The Fermi level pinning model was proposed for the former electrode. This electrode was very useful as the industrial anode material.