石墨电极制备多孔硅的蓝光发射研究

采用自制的双电解槽、高纯石墨电极，在一定浓度的氢氟酸乙醇溶液中阳极氧化腐蚀硅片制备一定孔隙度的多孔硅．利用荧光分析仪（激发波长250nm）分析了样品的光学特性，在470nm处观测到明显的蓝光发射峰．改变阳极腐蚀电流密度和腐蚀时间，研究腐蚀参数对光学特性的影响，结果表明：改变阳极电流密度和腐蚀时间不能引起470nm处峰位的蓝移或者红移；随着电流密度的增强，波长470nm峰值和半宽积分值先增大后减小；延长腐蚀时间，峰值和半宽积分值不断变大．同时，对实验现象进行了初步的理论解释．

Study on Blue Light Emission of Porous Silicon with Graphite as Electrode

Porous silicon （PS） with certain porosity is prepared by anodic etching Si （100） wafer in double cell with high purity graphite as anode in HF/ Ethanol solution. The optical properties of as-prepared PS by photoluminescence with EX = 250 nm is studied, and strong visual blue light could be observed at 470 nm. The effects of current density and corruption time on the optical properties are investigated. The results indicate that, the position of blue light peak is always at 470 nm no matter current density or corruption time changes. The peak intensity and half band integral increase first and then decrease as the current density increases, and increase as the corruption time prolongs. Meanwhile, theoretical explanations are given for these phenomena.