电子束蒸发制备PbI_2薄膜的光电性质研究  

Optical and Electrical Properties of PbI_2 Films Deposited by Electron Beam Evaporation

作　　者：朱兴华[1] 杨定宇[1] 魏昭荣[1] 李乐中[1] 杨维清[1] 杨军[1] 

机构地区：[1]成都信息工程学院光电技术学院,成都610225

出　　处：《真空科学与技术学报》2010年第5期567-570,共4页Chinese Journal of Vacuum Science and Technology

基　　金：国家自然科学基金(50902012);四川省应用基础研究项目(2009JY008)

摘　　要：采用电子束蒸发法制备了PbI2多晶薄膜，研究制备条件对薄膜光电性质的影响。结果表明，不同条件下制备的样品呈现不同的择优取向生长特征，但均属于六方相多晶结构。随着衬底温度的升高，PbI2薄膜的紫外．可见透过谱透过性能提高，光学带隙由室温时的2．33eV增大到200℃时的2．44ev。同时发现，不同源．衬间距制备样品的光谱透过性能和光学带隙基本相同。光致发光谱（PL）测试表明，薄膜的发光可能源自禁带中的缺陷能级跃迁，其PL发光峰的强度和展宽随源一衬间距的增大有明显变化。论文最后测试了PbI2薄膜在绿光LED照射下的光电导响应，发现制备样品的光电导响应性能与薄膜的沉积温度和源一衬间距有密切关系，光电导率的数量级约在10 -8～10 -9 Ω-1·cm-1之间。The Phi2 films were deposited by electron beam evaporation. Its micmstructures and properties were characterized with X-ray diffraction, ultraviolet and visible light spectroscopy, and photoluminescence （PL） spectroscopy. The impacts of the film growth conditions, including the substrate temperature, separation between electron source and substrate, and pressure, were evaluated to improve its optical and electrical properties. The results show that some deposition conditions significantly affect the morphologies and properties of the films. For example, different growth conditions resulted in hexagonal phase with different preferred orientations. As the substrate temperature increases, its transmittance increases and its optical gap increases fmm 2.33 eV at room temperature to 2.44 eV at 200 ℃. The PL intensity and peak width increases with a widening of the source-to-substrate spacing. Besides, the photoconductive response irradiated with green light emission diode also depends on substrate temperature, the source-substrate spacing. Possible mechanisms were also tentatively discussed.

关 键 词：PhI2薄膜 紫外-可见透过谱 光学带隙 光致发光谱 光电导 

分 类 号：O484.1[理学—固体物理]