多孔硅的电致发光研究

The Study of Electroluminescence of Porous Si

用电化学氧化方法在镀有Al电极的Si片上制备了多孔硅样品,在其上再镀一层ITO透明薄膜作为电极,得到了多孔硅电致发光器件。研究了该器件的结构形貌、光学和电学特性。通过扫描电镜可以观察到多孔硅的"树枝状"结构。器件的I-V特性曲线表明,当加正向偏压时,电流随着电压的增加快速增大,表现为正向导通。当加反向偏压时,电流很小,几乎为零,表现为反向截止,显示出单向导电性特点。器件的电致发光谱和光致发光谱相比,中心峰位和谱峰范围都基本一致,但有蓝移,这主要是因为二者的发光机制不同造成的。

The porous Si was prepared by electrochemical anodization of Si wafer with Al electrode,and ITO film was deposited on porous Si.Then porous Si electroluminescent device was obtained.The structure,optical and electrical properties of the device were studied.It can be seen that porous Si has ＂tree branch＂structure by scanning electron microscope（SEM）.The I-V characteristic indicates that,under forward applied voltage,the current increases with the increase of voltage,indicating forward breakover.Under reverse applied voltage,the current is low and even be zero,indicating reverse cut-off and it shows unilateral conductivity property.Comparing the electroluminescence spectrum with photoluminescence spectrum,the center peak position and Spectral peak range are basically the same,but a blueshift which was attributed to the different luminous mechanism.