在二维半导体与金属材料间引入范德华接触构建器件被认为是解决二维材料电接触问题的有效途径之一.然而,迄今为止,研究主要集中在半导体材料合成与改性上,而对金属材料的制备和性能的研究较少.在这项工作中,我们报道了利用化学气相沉积...在二维半导体与金属材料间引入范德华接触构建器件被认为是解决二维材料电接触问题的有效途径之一.然而,迄今为止,研究主要集中在半导体材料合成与改性上,而对金属材料的制备和性能的研究较少.在这项工作中,我们报道了利用化学气相沉积法可控合成厚度从3.5到10^(6)nm的层状MoO_(2)金属二维纳米片.利用X射线衍射、扫描隧道显微镜和透射电子显微镜对制备的MoO_(2)纳米片进行了系统表征,结果表明,制备的MoO_(2)为单斜晶型、晶质质量高、稳定性好.电学表征表明,MoO_(2)具有优良的导电性能,其导电率超过10^(6)S m^(-1),可与石墨烯和某些金属相媲美.此外,我们还通过引入MoO_(2)薄片作为范德华接触材料,探索了其在MoS_(2)场效应晶体管中的接触应用.所获得的MoS_(2)场效应晶体管表现出低肖特基势垒(36 m e V)和高载流子迁移率(210 cm^(2)V^(-1)s^(-1),10 K).这项工作为金属二维材料的可控制备和应用提供了新思路,并有望促进二维材料电子器件的发展.展开更多
The newly emerged two-dimensional(2D) semiconducting materials, owning to the atomic thick nature and excellent optical and electrical properties, are considered as potential candidates to solve the bottlenecks of tra...The newly emerged two-dimensional(2D) semiconducting materials, owning to the atomic thick nature and excellent optical and electrical properties, are considered as potential candidates to solve the bottlenecks of traditional semiconductors. However, the realization of high performance 2D semiconductorbased field-effect transistors(FETs) has been a longstanding challenge in 2D electronics, which is mainly ascribing to the presence of significant Schottky barrier(SB) at metal-semiconductor interfaces. Here, an additional contact gate is induced in 2D ambipolar FET to realize near ideal reconfigurable FET(RFET)devices without restrictions of SB. Benefitting from the consistently high doping of contact region, the effective SB height can be maintained at ultra-small value during all operation conditions, resulting in the near ideal subthreshold swing(SS) values(132 mV/decade for MoTe2 RFET and 67 mV/decade for WSe2 RFET) and the relatively high mobility(28.6 cm2/(Vs) for MoTe2 RFET and 89.8 cm2/(V s) for WSe2 RFET). Moreover, the flexible control on the doping polarity of contact region enables the remodeling and switching of the achieved unipolar FETs between p-type mode and n-type mode. Based on such reconfigurable behaviors, high gain complementary MoTe2 inverters are further realized. The findings in this work push forward the development of high-performance 2D semiconductor integrated devices and circuits.展开更多
基金supported by the National Key R&D Program of China(2022YFA1402501)the National Natural Science Foundation of China(51902098,51972105,U19A2090,U22A20138,62090035,and 12104144)+3 种基金the Key Program of Science and Technology Department of Hunan Province(2019XK2001 and 2020XK2001)the Science and Technology Innovation Program of Hunan Province(2021RC3061,2020RC2028,and 2021RC2042)the Natural Science Foundation of Hunan Province(2021JJ30132 and 2021JJ20016)China Postdoctoral Science Foundation(BX2021094,2020M680112,and 2021M690953)。
文摘在二维半导体与金属材料间引入范德华接触构建器件被认为是解决二维材料电接触问题的有效途径之一.然而,迄今为止,研究主要集中在半导体材料合成与改性上,而对金属材料的制备和性能的研究较少.在这项工作中,我们报道了利用化学气相沉积法可控合成厚度从3.5到10^(6)nm的层状MoO_(2)金属二维纳米片.利用X射线衍射、扫描隧道显微镜和透射电子显微镜对制备的MoO_(2)纳米片进行了系统表征,结果表明,制备的MoO_(2)为单斜晶型、晶质质量高、稳定性好.电学表征表明,MoO_(2)具有优良的导电性能,其导电率超过10^(6)S m^(-1),可与石墨烯和某些金属相媲美.此外,我们还通过引入MoO_(2)薄片作为范德华接触材料,探索了其在MoS_(2)场效应晶体管中的接触应用.所获得的MoS_(2)场效应晶体管表现出低肖特基势垒(36 m e V)和高载流子迁移率(210 cm^(2)V^(-1)s^(-1),10 K).这项工作为金属二维材料的可控制备和应用提供了新思路,并有望促进二维材料电子器件的发展.
基金supported by the National Natural Science Foundation of China (U19A2090, 51902098, 51972105, 51525202, and 61574054)the Hunan Provincial Natural Science Foundation (2018RS3051)。
文摘The newly emerged two-dimensional(2D) semiconducting materials, owning to the atomic thick nature and excellent optical and electrical properties, are considered as potential candidates to solve the bottlenecks of traditional semiconductors. However, the realization of high performance 2D semiconductorbased field-effect transistors(FETs) has been a longstanding challenge in 2D electronics, which is mainly ascribing to the presence of significant Schottky barrier(SB) at metal-semiconductor interfaces. Here, an additional contact gate is induced in 2D ambipolar FET to realize near ideal reconfigurable FET(RFET)devices without restrictions of SB. Benefitting from the consistently high doping of contact region, the effective SB height can be maintained at ultra-small value during all operation conditions, resulting in the near ideal subthreshold swing(SS) values(132 mV/decade for MoTe2 RFET and 67 mV/decade for WSe2 RFET) and the relatively high mobility(28.6 cm2/(Vs) for MoTe2 RFET and 89.8 cm2/(V s) for WSe2 RFET). Moreover, the flexible control on the doping polarity of contact region enables the remodeling and switching of the achieved unipolar FETs between p-type mode and n-type mode. Based on such reconfigurable behaviors, high gain complementary MoTe2 inverters are further realized. The findings in this work push forward the development of high-performance 2D semiconductor integrated devices and circuits.
