Hefei National Laboratory for Physical Sciences at the Microscale, Collaborative Innovation Center of Chemistry for Energy Materials, and School of Chemistry and Materials Science, University of Science and Technology of China, Hefei, Anhui 230026 (P. R. China) http://staff.ustc.edu.cn/∼yjxiong/
Angew Chem Int Ed Engl. 2014 May 12;53(20):5107-11. doi: 10.1002/anie.201310635. Epub 2014 Apr 2.
A practical strategy is proposed to facilitate the migration of holes in semiconductor (the low rate of which limits photocatalytic efficiency) by taking advantage of the Schottky barrier between p-type semiconductor and metal. A high work function is found to serve as an important selection rule for building such desirable Schottky junction between semiconductor surface facets and metal. The intrinsic charge spatial distribution has to be taken into account when selecting the facets, as it results in accumulation of photoexcited electrons and holes on certain semiconductor facets. Importantly, the facets have a high work function, the same characteristic required for the formation of Schottky junction in a p-type semiconductor-metal hybrid structure. As a result, the semiconductor crystals in the hybrid design may be better enclosed by single facets with high work function, so as to synergize the two effects: Schottky barrier versus charge spatial separation.
提出了一种实用策略，通过利用 p 型半导体和金属之间的肖特基势垒来促进半导体中孔的迁移（其低迁移率限制了光催化效率）。发现高功函数是在半导体表面晶面和金属之间构建这种理想肖特基结的重要选择规则。在选择晶面时必须考虑本征电荷空间分布，因为它会导致光激发电子和空穴在某些半导体晶面上积累。重要的是，这些晶面具有高功函数，这是在 p 型半导体-金属混合结构中形成肖特基结所必需的特征。因此，在混合设计中，半导体晶体可能会被具有高功函数的单一晶面更好地包围，从而协同两种效应：肖特基势垒与电荷空间分离。
