多孔硅中电子光跃迁过程的研究

用硅-氧化硅复合纳米材料的能带混合模型研究了多孔硅中的各类电子状态。分析了各种状态的能带属性及其量子限制特性，从而解释了实验中观察到的量子限制态和非量子限制态。在有效质量理论框架下计算了不同能级间的光跃迁矩阵元，得出了带内和带间状态间的跃迁选择定则。运用所计算的结果较好地解释了实验中观察到的PL和CL光谱中的量子限制态、非量子限制态、元激发陷阱以及各种不同的谱峰。最后从多孔硅发光特性与半导体材料及杂质、缺陷发光的对比中阐明了这种纳米发光材料的特征。由此笔者提出了研究硅一氧化硅复合纳米材料来开发新的硅基发光材料、器件和集成电路的新途径。

Investigation on Transition Mechanism for Electrons in Porous Silicon

By using a band mixing model in nanometer material composed of Siand SiO2, various electronic states in porous silicon are investigaed in this paper.Through the analysis of band attribution and quantum confined characteristic forvarious states, the quantum confined states and non-confined states observed experimentally are explained. Under the framework of effective mass theory, the optical transition probability between different energy levels is calculated from whichthe transition selection rule is obtained. These results reasonably expound the observed PL and CL spectra for the quantum confined states, non-confined states,and traps of elementary excitation in porous silicon. Finally, the luminous behaviorfor this nanometer material is clarified by comparing it with that of bulk semicollductor material and luminous centres produced by impurity and defect, andconsequently the author proposes a new way to develop new Si-based luminous material, devices and integrated circuits from the investigation of Si-SiO2 compositenanometer material.