多孔硅材料的电致发光特性及多孔形成机理的研究

Electroluminescent Characteristics Structure and Morphology of Porous Sillicon

系统考察了衬底硅材料的掺杂类型、晶向、阳极氧化电流密度、时间等工艺条件对多孔硅电致发光特性的影响，考察了其微观结构．实验表明，电流密度的增大或氧化时间的增长，使多孔硅的光发射谱（ＰＬ）“蓝移”、发光持续时间延长，当ＨＦ与乙醇的配比为１１时，有较强的发光强度．多孔硅具有“树枝”状或“网”状的结构，其形成与电流密度、硅基片的类型、掺杂浓度以及晶向有关．用ＤＬＡ（Ｄｉｆｕｓｉｏｎ－ＬｉｍｉｔｅｄＡｇ－ｇｒｅｇａｔｉｏｎ）模型研究了多孔硅的多孔形成过程和机理，讨论了多孔硅的多孔形成与工艺条件的关系．

We have studied the electroluminesent characteristics microstructure and morphology of porous sillicon are studied. It is observed that the intensity peaks of PL shift towards to blue color and the standing time of luminescence elongates with increasing the current density or etch time. The porous Si samples have stronger luminescent intensity when the anodizing solution used was a 1∶1 dilution in alcohol or 49% HF. The structure of porous is considered to be “arboresence” or “porous network” which are related to the current density, the types of Si substractes and doping concentration. In DLA model the morphology of porous Si was simulated by computer, and the forming process and mechanism of porous Si and their relations to anodizating conditions were investigated.