缺陷与掺杂共存的黑磷烯甲醛传感行为的电子理论  

Electronic theoretical study on sensing behaviors ofdefects and doping coexistence of blackphosphorene to formaldehyde

作　　者：张国英[1] 焦兴强 刘业舒 张安国[1] 孟春雪 Zhang Guo-Ying;Jiao Xing-Qiang;Liu Ye-Shu;Zhang An-Guo;Meng Chun-Xue(College of Physics Science and Technology,Shenyang Normal University,Shenyang 110034,China;College of Life and Health Sciences,Northeastern University,Shenyang 110819,China)

机构地区：[1]沈阳师范大学物理科学与技术学院,沈阳110034 [2]东北大学生命科学与健康学院,沈阳110819

出　　处：《物理学报》2020年第23期214-222,共9页Acta Physica Sinica

基　　金：辽宁省教育厅科学研究一般项目(批准号:LZGD2019003)资助的课题.

摘　　要：黑磷烯(black phosphorene,BP)因其“褶皱”的晶格结构而具有较高的比表面积,在气体吸附及气体传感器方面应用具有很大的优势.掺杂及缺陷对其传感性有较大的影响.本文以基于密度泛函理论的第一性原理方法为基础探究了本征、Al掺杂、含P原子空缺以及P空位与Al掺杂共存的黑磷烯体系吸附甲醛前后的传感行为.通过建立含缺陷和掺杂吸附体系的结构模型,计算得出了吸附能、能带结构及电荷转移等电子结构参数.结果表明,本征BP烯以及含P原子空缺的BP烯体系对甲醛分子吸附能力较弱,P原子空缺对电导率以及电荷转移没有影响,所以本征黑磷烯不适合用于传感器材料.Al掺杂和P空位与Al掺杂共存的BP烯体系,吸附甲醛分子的能力明显比前两种情况增强,电荷转移明显增加,改变了载流子浓度,提高了电导率.此外,在能带图中明显看到产生一个杂质能级,有效带隙明显变窄,表明Al掺杂提高了纯净和含P空位黑磷烯的传感性.因此,Al掺杂和P空位与Al掺杂共存的BP烯体系预计可成为一种新的传感器材料.Black phosphorene(BP)has a high specific surface area due to its puckered honeycomb lattice structure,so it has great advantages in gas sensor applications.Doping and defects have a great effect on its sensitivity.Our aim is to obtain an insight into the sensing mechanism of black phosphorene towards CH2O,a hazardous organic compound.Based on the first-principles method of density functional theory(DFT),the sensing behaviors of the BP system,with intrinsic,Al doped,P vacancy-defected and P-vacancy and Al doping coexistent,before and after CH2O adsorption are studied.By establishing the structural models of four BP systems,the values of adsorption energy,energy band structure and charge transfer are calculated.Calculation results show that CH2O molecule prefers to be adsorbed perpendicular to the P vacancy-defected BP nanosheet with oxygen atom on the top site and close to the sheet.For the intrinsic,Al doped,P-vacancy and Al doping coexisting BP nanosheet,the CH2O molecule tilts towards the sheet surface.It is found that the CH2O adsorption on intrinsic BP nanosheet(adsorption energy is 0.179 eV)is very weak.In contrast,the adsorption of CH2O to the BP systems,with P vacancy-defected BP,Al doped,P-vacancy and Al doping coexistent,shows relatively high affinity(0.875,0.542,0.824 eV).Thus,Al doping,P vacancy or P-vacancy and Al-doping coexistence can substantially improve the adsorption ability of BP systems towards CH2O.In order to investigate the sensing mechanism of BP systems,the electronic properties such as the density of states,energy band and charge transfer are calculated.The change of energy gap of intrinsic BP nanosheet before and after CH2O adsorption is 0.024 eV,and that for P vacancy-defected BP nanosheet is zero.In addition,P atom vacancy has no effect on charge transfer.These suggest that the conductivity of intrinsic BP or P vacancydefected BP nanosheet has not obviously changed,thereby,they are not suitable for sensor materials.For the BP system with Al doping or the coexistence of P vacancy and A

关 键 词：黑磷烯 第一性原理 甲醛 传感行为 

分 类 号：TP212[自动化与计算机技术—检测技术与自动化装置] O647.31[自动化与计算机技术—控制科学与工程]