一种复合掺杂方式对石墨烯载流子浓度的调制  

Modulation of graphene carrier density by a mixed doping route

作　　者：唐静 范晓东 曾长淦 TANG Jing;FAN Xiaodong;ZENG Changgan(Department of Physics, University of Science and Technology of China, Hefei 230026, China)

机构地区：[1]中国科学技术大学物理系,安徽合肥230026

出　　处：《中国科学技术大学学报》2020年第6期839-843,共5页JUSTC

基　　金：中国科学院战略性先导科技专项(XDC07010000)资助.

摘　　要：石墨烯显著的优点是其载流子浓度极易调控.目前已经发展出很多载流子浓度调控方法,其中栅压调节是应用最广的一种手段.但是在实际应用中,栅压也有一定的局限性.例如一些设计电路、测试仪器并不能承受几十甚至上百伏的高压.最近出现一种电子束辐照掺杂的方式,可以局域、连续地调控石墨烯载流子浓度,但调控范围较小.这里应用硝酸掺杂结合电子束辐照的复合方式,实现了石墨烯载流子浓度的大范围、连续调控.通过分析扫描近场光学显微镜和电输运测试结果,发现此复合方式可以将石墨烯载流子浓度从2.15×10^(13) cm^(-2)调控至-1.49×10^(12) cm^(-2),效果相当于常用的300 nm二氧化硅介电层320 V的栅压变化.另外,通过电子束曝光可以将石墨烯加工成预设的电子图案.这种简单、高效的复合掺杂方式有着非常广泛的应用前景.Graphene has a significant advantage that its carrier density can be easily tuned.Various methods for controlling carrier density have been proposed,of which gate tuning is the most widely used.However,in practical applications,gate tuning also has some limitations.For example,some designed circuits and test instruments cannot stand high voltages over hundreds or even tens of volts.Recently,a method of doping with electron beam irradiation has appeared,which can change graphene carrier density locally and continuously,but the tuning range is small.Here a new mixed doping route combining HNO3 doping and electron beam irradiation was presented,which shows greater ability to tune carrier density continuously in a larger range.By analyzing the results of the scanning near-field optical microscope and electrical transport,it was found that the mixed doping route adjusts the graphene carrier density from 2.15×10^(13) cm^(-2) to-1.49×10^(12) cm^(-2),which is equivalent in tuning effect to 320 V for gate tuning of the 300 nm silicon dioxide.In addition,graphene can be written into pre-designed electric patterns via electron beam irradiation,which is potentially widely applicable.

关 键 词：电子束照射 硝酸掺杂 局域掺杂 复合掺杂 载流子浓度 

分 类 号：O469[理学—凝聚态物理]