Graphene-based heterostructure is one of the most attractive topics in physics and material sciences due to its intriguing properties and applications. We report the one-step fabrication of a novel graphene/Mo2C heter...Graphene-based heterostructure is one of the most attractive topics in physics and material sciences due to its intriguing properties and applications. We report the one-step fabrication of a novel graphene/Mo2C heterostructure by using chemical vapor deposition（CVD）. The composition and structure of the heterostructure are characterized through energydispersive spectrometer, transmission electron microscope, and Raman spectrum. The growth rule analysis of the results shows the flow rate of methane is a main factor in preparing the graphene/Mo2C heterostructure. A schematic diagram of the growth process is also established. Transport measurements are performed to study the superconductivity of the heterostructure which has potential applications in superconducting devices.展开更多
本文报道了一种在蓝宝石衬底上NaOH辅助化学气相沉积(CVD)生长有序排列单层MoS2条带的方法.MoS2条带具有优良的单晶性,其载流子迁移率为~150 cm^2V^-1s^-1,在550 nm波长下的光学响应为103 mA W^-1.单层MoS2条带在蓝宝石衬底上具有两种...本文报道了一种在蓝宝石衬底上NaOH辅助化学气相沉积(CVD)生长有序排列单层MoS2条带的方法.MoS2条带具有优良的单晶性,其载流子迁移率为~150 cm^2V^-1s^-1,在550 nm波长下的光学响应为103 mA W^-1.单层MoS2条带在蓝宝石衬底上具有两种生长方式,其中一种为受层间范德华力以及晶格影响的取向生长,另一种为受蓝宝石台阶约束的平行生长.NaOH的引入量对MoS2形态与取向起重要作用,可以实现从取向性三角形晶畴,受衬底晶格影响的取向MoS2条带,受衬底台阶约束的平行条带,再到大尺寸杂乱取向三角形晶畴的连续可调.本文的结果有利于推动MoS2的基础研究及器件应用,也为合成其他一维和二维纳米结构开辟了新途径.展开更多
Superior graphene-metal contacts can improve the performance of graphene devices. We report on an experimental demonstration of Ge/Au/Ni/Au-based ohmic contact on graphene. The transfer length method （TLM） is adopte...Superior graphene-metal contacts can improve the performance of graphene devices. We report on an experimental demonstration of Ge/Au/Ni/Au-based ohmic contact on graphene. The transfer length method （TLM） is adopted to measure the resistivity of graphene-metal contacts. We designed a process flow, which can avoid residual photoresist at the interface of metal and graphene. Additionally, rapid thermal annealing （RTA） at different temperatures as a post-processing method is studied to improve graphene-metal contact. The results reveal that the contact resistivity of graphene and Ge/Au/Ni/Au can reach 10^-5 Ω· cm^2 after RTA, and that 350 ℃ is optimum annealing temperature for the contact of graphene-Ge/Au/Ni/Au. This paper provides guidance for fabrication and applications of graphene devices.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.1402342,11574338,and 11274333)the Hundred Talents Program of Chinese Academy of Sciences,the International Collaboration and Innovation Program on High Mobility Materials Engineering,Chinese Academy of Sciences(Grant No.KGZD-EW-303)the“Strategic Priority Research Program(B)”of the Chinese Academy of Sciences(Grant No.XDB04040300)
文摘Graphene-based heterostructure is one of the most attractive topics in physics and material sciences due to its intriguing properties and applications. We report the one-step fabrication of a novel graphene/Mo2C heterostructure by using chemical vapor deposition（CVD）. The composition and structure of the heterostructure are characterized through energydispersive spectrometer, transmission electron microscope, and Raman spectrum. The growth rule analysis of the results shows the flow rate of methane is a main factor in preparing the graphene/Mo2C heterostructure. A schematic diagram of the growth process is also established. Transport measurements are performed to study the superconductivity of the heterostructure which has potential applications in superconducting devices.
基金This work was financially supported by the Science and Technology Commission of Shanghai Municipality(18511110700).
文摘本文报道了一种在蓝宝石衬底上NaOH辅助化学气相沉积(CVD)生长有序排列单层MoS2条带的方法.MoS2条带具有优良的单晶性,其载流子迁移率为~150 cm^2V^-1s^-1,在550 nm波长下的光学响应为103 mA W^-1.单层MoS2条带在蓝宝石衬底上具有两种生长方式,其中一种为受层间范德华力以及晶格影响的取向生长,另一种为受蓝宝石台阶约束的平行生长.NaOH的引入量对MoS2形态与取向起重要作用,可以实现从取向性三角形晶畴,受衬底晶格影响的取向MoS2条带,受衬底台阶约束的平行条带,再到大尺寸杂乱取向三角形晶畴的连续可调.本文的结果有利于推动MoS2的基础研究及器件应用,也为合成其他一维和二维纳米结构开辟了新途径.
基金financially supported by the National Defense Technology Innovation Special Zone Project, the National Natural Science Foundation of China (51402342)the Science and Technology Commission of Shanghai Municipality (20501130200)。
文摘Superior graphene-metal contacts can improve the performance of graphene devices. We report on an experimental demonstration of Ge/Au/Ni/Au-based ohmic contact on graphene. The transfer length method （TLM） is adopted to measure the resistivity of graphene-metal contacts. We designed a process flow, which can avoid residual photoresist at the interface of metal and graphene. Additionally, rapid thermal annealing （RTA） at different temperatures as a post-processing method is studied to improve graphene-metal contact. The results reveal that the contact resistivity of graphene and Ge/Au/Ni/Au can reach 10^-5 Ω· cm^2 after RTA, and that 350 ℃ is optimum annealing temperature for the contact of graphene-Ge/Au/Ni/Au. This paper provides guidance for fabrication and applications of graphene devices.
