Na/Si(111)7×7表面对称特性的研究

A symmetry property investigation of a Na/Si(111)7×7 interface by means of optical second harmonic generation

简述了光学二次谐波振荡原理 ,并用这种非线性光学方法 ,在表面共振激发条件下 ,通过入射光的 0°和 4 5°入射 ,对吸附了碱性金属Na原子的半导体材料Si(111) 7× 7表面结构的对称性进行了研究 .给出了最新的实验结果 ,并加以讨论 .实验结果表明 ,由于Na原子在Si(111) 7× 7表面上的吸附 ,使得该表面原本有序的 3m对称结构发生了很大的变化 .

The fundamentals of optical second harmonic generation (SHG) is briefly described in this paper. By measuring the reflected SHG intensities following surface near-resonant excitation, the 3m symmetry of a clean Si(111)7×7 surface is modified.The experimental results are obtained with a light beam at normal incidence and at an 45° angle of incidence geometry. Explanation and discussion of the experimental results are also given in the paper.