Chemical Control of Recombination at Semiconductor Interfaces

该项目属于分析化学和表面化学的一般领域，以及半导体电化学和光化学的子领域。将通过实验研究半导体-电解液界面上界面电子转移的机理，以检验当前的结行为理论。此外，还将研究电子-空穴复合位置的化学控制。我们将通过研究半导体表面与不稳定取代的过渡金属络合物的反应中半导体表面的化学和物理性质，来研究在刻蚀的硅和砷化镓表面上重要的表面陷阱位置的反应性。半导体-络合物相互作用的光谱研究将被用来阐明修饰表面的金属氧化态、配位壳层和电子性质。将研究硅表面的光电化学钝化。还将研究晶体和非晶硅在高注入条件下的电子转移动力学。为了推断大多数载流子的表面浓度与界面电子转移速率之间的关系，将进行精心准备的半导体表面的实验。将获得有关电性重要表面位置的化学信息。这些结果将为理解用于电子设备和太阳能转换的半导体的加工提供基础信息。

This project is in the general area of analytical and surface chemistry and in the subfields of semiconductor electro- chemistry and photochemistry. Mechanistic aspects of interfacial electron transfer at the semiconductor-electrolyte interface will be investigated experimentally in order to test current theories of junction behavior. In addition, chemical control of electron-hole recombination sites will be investigated. The reactivity of the electrically important surface trapping sites at etched silicon and gallium arsenide surfaces will be studied by investigating the chemistry and resultant physical properties of semiconductor surfaces in reactions with substitution-labile transition metal complexes. Spectroscopic studies of the semiconductor-complex interaction will be performed to elucidate the metal oxidation state, coordination shell, and electronic properties of the modified surface. Photoelectrochemical passivation of silicon surfaces will be studied. Electron transfer kinetics under high injection conditions in crystalline and amorphous silicon will be also be investigated. Experiments with carefully prepared semiconductor surfaces will be performed in order to deduce relations between the surface concentration of majority carriers and the rate of interfacial electron transfer. Chemical information regarding electrically important surface sites will be obtained. These results will provide information basic to the understanding of the processing of semiconductors for electronic devices and solar energy conversion.