气体吸附对V掺杂石墨烯电子结构与光学性质的影响  

Effects of gas adsorption on electronic structure and optical properties of V-doped graphene

作　　者：王梦娟 顾芳 李大林 刘清惓[1] 侯智 张加宏[1] WANG Meng-Juan;GU Fang;LI Da-Lin;LIU Qing-Quan;HOU Zhi;ZHANG Jia-Hong(School of Electronics and Information Engineering,Nanjing University of Information Science&Technology,Nanjing 210044,China;School of Physics and Optoelectronic Engineering,Nanjing University of Information Science&Technology,Nanjing 210044,China)

机构地区：[1]南京信息工程大学电子与信息工程学院,南京210044 [2]南京信息工程大学物理与光电工程学院,南京210044

出　　处：《原子与分子物理学报》2024年第5期118-124,共7页Journal of Atomic and Molecular Physics

基　　金：国家自然科学基金(41875035,42275143)。

摘　　要：基于密度泛函理论 (DFT )的广义梯度近似 (GGA ),采用第一性原理方法研究了气体分子吸附对V掺杂石墨烯的吸附能、电子结构与光学性质的影响.能带结构计算表明:吸附NO_(2) 分子的V掺杂石墨烯的带隙显著增加,从0 eV变为0.368 eV,由金属性转变为半导体特性,而吸附CO与NH_(3) 分子的V掺杂石墨烯的带隙则变化很小.三种吸附构型 (NO_(2) , CO, NH_(3) )的吸附能分别为-8.499 eV、-2.05 eV和-2.01 eV,说明V掺杂石墨烯对NO_(2) 气体分子吸附最强.进而计算了本征、V掺杂石墨烯及其吸附NO_(2) 分子的光学性质,结果表明:随着V掺杂与吸附NO_(2) 气体,石墨烯介电吸收峰值有所增大,介电峰位向低能量区域移动;本征石墨烯仅吸收紫外光,V掺杂石墨烯吸附NO_(2) 分子可以明显拓宽光吸收的光谱范围;掺杂与吸附使得石墨烯光电导率显著增强,能在红外与可见光区产生光电流.上述结果表明V掺杂石墨烯吸附NO_(2) 后材料电子结构和光学性质明显变化,能够作为光学气敏传感材料检测NO_(2) 气体.Based on the generalized gradient approximation (GGA ) under the density functional theory system, the first-principles method was used to investigate the effect of gas molecule adsorption on the adsorption energies, energy band structures and optical properties of the V-doped graphene. The band structure calculation showed that the band gap of V-doped graphene adsorbing NO_(2) gas molecule is increased from 0 eV to 0.368 eV, and its material property has also changed from metal to semiconductor. However, the band gaps of V-doped graphene adsorbing CO and NH_(3) molecules are almost unchanged. The adsorption energies of the three adsorption (NO_(2) , CO, NH_(3) ) configurations are -8.499 eV, -2.05 eV and -2.01 eV, respectively, indicating that V-doped graphene has the best adsorption effect on NO_(2) gas molecules. Furthermore, the optical properties of intrinsic and doped graphene when adsorbing NO_(2) gas molecules were calculated. The results displayed that the dielectric absorption peak value of graphene is increased with V doping and adsorbing NO_(2) gas, and the dielectric peak position is moved to the low energy region;Intrinsic graphene can only absorb ultraviolet light, and V-doped graphene can significantly improve the spectral range of light absorption after absorbing NO_(2) molecules. The photoconductivity of graphene can be significantly enhanced by the doping and adsorption, and the photocurrent can be generated in the infrared and visible light regions. The above research results show that the electronic structures and optical properties of V-doped graphene adsorbing NO_(2) have been significant changed, and it can be applied as an optical gas sensing material to detect NO_(2) gas.

关 键 词：V掺杂石墨烯 第一性原理 气体吸附 电子结构 光学性质 

分 类 号：O484[理学—固体物理]