II-VI族硫化物堆垛层错结构的可控制备及电荷分离特性

项目名称： II-VI族硫化物堆垛层错结构的可控制备及电荷分离特性

项目编号： No.51302046

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 一般工业技术

项目作者： 张凯

作者单位： 国家纳米科学中心

项目金额： 25万元

中文摘要： 晶体缺陷在光催化过程中具体作用的相关研究仍处于起步阶段，特别是特殊面缺陷结构对半导体材料光催化性能的影响尚未见文献报道。II-VI族硫化物半导体材料因其自身结构特点极易形成堆垛层错结构。该结构是典型的面缺陷结构，由晶体内部原子排列次序改变所形成，不改变晶体内部点阵完整性。文献报道II-VI族堆垛层错结构会导致晶体内部形成内建电场并影响光生电荷的空间分布，最终引起光电压叠加，产生反常光伏效应。显然，光生电荷的分离和迁移极有可能受到该结构的重要影响，聚焦于II-VI族硫化物堆垛层错在光催化过程关键作用的研究将具有重要的科学意义。因此，本研究将选择II-VI族硫化物为研究对象，设计向该类半导体材料中引入堆垛层错结构的新型制备方法，以探明堆垛层错对其光催化性能的具体影响，揭示其在光生载流子分离和迁移过程中的关键作用，期望能够为半导体光催化材料研究提供重要的科学依据和研究基础。

中文关键词： II-VI族硫化物；堆垛层错；闪锌矿-纤锌矿超晶格；电荷分离；光催化制氢

英文摘要： The roles of crystal defects during the separation and migration of phtogenerated electrons and holes in photocatalytic reactions are still not clear up to now, especially there are no research works focused on the influences of planar defects. As known, stacking faults, planar defects which are quite different from point defects, are always resulted by the changes of atomic stacking sequences with no affect on the lattice integrity. Thus stacking faults may play different roles in photocatalysis compared to those of point defects. Investigations on the crucial roles of stacking faults during photocatalytic process is of great scientific and theoretical importances. II-VI group sulphide semiconductors have been extensively reported to exist in many polytypes consisting of periodically arranged zinc-blende and wurtzite layers induced by stacking faults. The self-polarization of hexagonal structure causes the formation of internal fields with oppsite directions in the neighbouring hexagonal and cubic segments, leading to a significant difference in electrostatic potential around the structure interface.Thus, the photogenerated electrons and holes migrate towards different directions, resulting in the anomalous photovoltaic effect. Obviously, the stacking faults in II-VI sulphide semiconductors are very likely to b

英文关键词： II-VI semiconductor；Stacking faults；ZB-WZ superlattice；Charge Separation；Photocatalytic hydrogen production