基于原子力显微镜的G/FTO双层薄膜接触特性研究

Contact Characteristics of G/FTO Bilayer Films Based on Atomic Force Microscopy

本文采用湿法刻蚀法将单层石墨烯(G)与掺氟二氧化锡(FTO)薄膜复合在一起,采用拉曼(Raman)光谱、聚焦离子束(FIB)和透射电子显微镜(TEM)研究了G/FTO双层薄膜的结构、表面和界面形貌、元素分布等信息;采用基于原子力显微镜(AFM)的开尔文探针力显微镜(KPFM)和导电原子力显微镜(C-AFM)研究了FTO薄膜和G/FTO双层薄膜的形貌、接触电势差(CPD)、功函数、接触势垒。结果表明,FTO薄膜和G/FTO双层薄膜的接触电势差分别为-0.474、-0.441 V,两者功函数分别为5.329、5.296 eV。与FTO薄膜相比,G/FTO双层薄膜的迁移率由21.26 cm^(2)·V^(-1)·s^(-1)增加到23.82 cm^(2)·V^(-1)·s^(-1)。FTO薄膜和G/FTO双层薄膜相应的势垒高度分别(0.39±0.06) V和(0.33±0.05) V,G/FTO双层薄膜的势垒高度更小。

Single layer graphene(G) and fluoride doped tin dioxide(FTO) thin film were compounded together by wet etching method.The structure,surface and interface topography and elemental distribution of G/FTO bilayer film were investigated by Raman spectroscopy,focused ion beam(FIB) and transmission electron microscopy(TEM).The topography,contact potential difference(CPD),work function and contact barrier of FTO film and G/FTO bilayer film were investigated using Kelvin probe force microscopy(KPFM) and conductive atomic force microscopy(C-AFM) based on atomic force microscopy(AFM).The results show that the contact potential difference of FTO film and G/FTO bilayer film is-0.474 and-0.441 V,respectively,and the work function of the two films is 5.329 and 5.296 eV,respectively.Compared with FTO film,the mobility of G/FTO bilayer film increases from 21.26 cm^(2)·V^(-1)·s^(-1) to 23.82 cm^(2)·V^(-1)·s^(-1).The corresponding barrier height of FTO film and G/FTO bilayer film is(0.39±0.06) V and(0.33±0.05) V,respectively,and the barrier height of G/FTO bilayer film is smaller.