多孔硅的光致发光机制  

Photoluminescence Mechanism of Porous Silicon

作　　者：王晓静[1] 李清山[1] 

机构地区：[1]曲阜师范大学物理系,山东曲阜273165

出　　处：《发光学报》2004年第4期396-400,共5页Chinese Journal of Luminescence

基　　金：山东省自然科学基金资助项目 (Y2 0 0 2A0 9)

摘　　要：人们已经提出了许多解释多孔硅发光的理论模型 ,每个模型都可以针对某些实验现象做出合理的解释 ,而对其他的实验结果就可能无法解释甚至相悖 ,因此多孔硅的发光机制至今仍是需要进一步研究和解决的问题。通过改变阳极氧化的条件 ,制得了一系列样品 ,其光致发光谱主要有四个峰。随着制备条件的改变 ,各个峰位的变化不大 ,但峰值强度比的变化比较大。随着自然氧化时间的延长 ,各个峰位的变化很小 ,有红移也有蓝移 ,有的则基本不变 ;而峰值强度的减弱幅度较大 ,但对应于各个峰位幅度的减弱是均衡的。分析实验现象产生的原因 ,认为多孔硅的发光是多种发光机制共同作用的结果 ;多孔硅纳米量子线的一定尺寸分布 ,不仅使光致发光谱存在一定的带宽 ,而且也是产生多峰现象的原因之一 ;Photoluminescence mechanism of porous silicon has been studied and discussed for many years, a lot of academic models to explain this phenomenon were proposed. Each model can interpret certain experimental results, but can’t explain others or even can be contradictious, so it is debated and studied to date. The substrates used in this work were all p-type Si wafer with resistivity between 8～13 Ω·cm and (111) crystalline orientation. The samples were prepared by anodic etching method in double-cell. The anodic etching was carried out in a solution of HF and ethanol at constant current density and at room temperature. Specimens were prepared under different conditions of current density, solution concentration and erosion time. Photoluminescence spectra of the samples have mostly four peaks: Peak 1: (660±5) nm;Peak 2: (690±10) nm;Peak 3: (740±5) nm and Peak 4: (775±5) nm. Energy positions corresponding to peak wavelength are:(1.88±0.02) eV; (1.796±0.03) eV; (1.675±0.01) eV and (1.599±0.01) eV respectively. The energy range is 1.6～1.9 eV. Relation between preparation conditions and peak wavelength and intensity is set out. The peak wavelength shifts in a little range, but the intensity changes greatly with the difference of preparation conditions, so whole peak position shifts and full width at half maximum changes obviously. Relation between aging time and peak wavelength and intensity is set out also. With aging time, three main peak position changes less, some shift to the blue and some are almost immobile and others shift to the red, but the peak intensity weaken more and more.Different preparation conditions can generate different microcosmic structure, porous silicon with different structure perhaps has more different optical properties and photoluminescence properties. Structure and photo-luminescence properties of prepared porous silicon can change with the process of preservation. Experimental results suggest that photoluminescence of porous silicon is a result of multiple photoluminescenc

关 键 词：多孔硅 多峰发射 发光机制 尺寸分布 

分 类 号：O482.31[理学—固体物理]