多孔硅锗的制备及其近红外发光增强  

Preparation of Porous SiGe and Emission Enhancement in Near-infrared Area

作　　者：吴克跃[1,2] 黄伟其[1,2] 许丽[1,2] 

机构地区：[1]贵州大学理学院物理系 [2]光电子技术与应用重点实验室,贵州贵阳550025

出　　处：《发光学报》2007年第4期585-588,共4页Chinese Journal of Luminescence

基　　金：国家自然科学基金资助项目(10547006)

摘　　要：用激光照射辅助电化学刻蚀硅锗合金样品能够形成多种低维纳米结构。在硅锗合金上形成的多孔状结构在波长为725 nm处有很强的光致发光(PL)峰,PL的增强效应不能单独用量子受限模型来解释。我们提出新的模型来解释这种低维纳米结构的PL增强效应。Some kinds of low-dimensional nanostructures can be formed by irradiation of laser on the SiGe alloy sample. Dots structure and lines structure on the Si1-x Gex film were formed under a weaker irradiation of laser. Nano-strap pieces structure after digging up the Si1-x Gex layer with a stronger laser. Porous structure on the substrate under anodizing and irradiating for 30 min, when the Si1-x Gex layer is almost dug out; oxygen distribution on the porous structure is measured. We have studied the photoluminescence （PL） of the porous structure of SiGe where the PL intensity at 725 nm wavelength increases obviously. The effect of intensityenhancing in the PL peaks cannot be explained within the quantum confinement alone. A new model of threelevel system associated with the crystal-oxide interface state has been proposed for interpreting the PL peak at 725 nm wavelength： An injection photon excites an electron in the top of valence band to jump up into the bottom of the conduction band which is called to an absorption jumping process whose gap width increases because of the quantum confinement effect. It is a fast process for electron to jump from the valence band to the conduction band. Then the electrons are very rapidly caught into the interface state distributing in the region below the conduction band. These trap states have a certain distribution round the center state of 1.7 eV energy level. We think that the states distribution is probably related to the frequency distribution of the PL emission. Electrons in the interface state have long lifetimes, and population inversion between the top of the valence band and the interface state is thus the PL peak at 725 nm wavelength. possible from which we can explain the enhancing effect of the PL peak at 725 nm wavelength.

关 键 词：多孔硅锗 低维纳米结构 PL增强 界面态 

分 类 号：O614.346[理学—无机化学]