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.