Research on two-dimensional(2D) materials has been explosively increasing in last seventeen years in varying subjects including condensed matter physics, electronic engineering, materials science, and chemistry since ...Research on two-dimensional(2D) materials has been explosively increasing in last seventeen years in varying subjects including condensed matter physics, electronic engineering, materials science, and chemistry since the mechanical exfoliation of graphene in 2004. Starting from graphene, 2D materials now have become a big family with numerous members and diverse categories. The unique structural features and physicochemical properties of 2D materials make them one class of the most appealing candidates for a wide range of potential applications. In particular, we have seen some major breakthroughs made in the field of 2D materials in last five years not only in developing novel synthetic methods and exploring new structures/properties but also in identifying innovative applications and pushing forward commercialisation. In this review, we provide a critical summary on the recent progress made in the field of 2D materials with a particular focus on last five years. After a brief backgroundintroduction, we first discuss the major synthetic methods for 2D materials, including the mechanical exfoliation, liquid exfoliation, vapor phase deposition, and wet-chemical synthesis as well as phase engineering of 2D materials belonging to the field of phase engineering of nanomaterials(PEN). We then introduce the superconducting/optical/magnetic properties and chirality of 2D materials along with newly emerging magic angle 2D superlattices. Following that, the promising applications of 2D materials in electronics, optoelectronics, catalysis, energy storage, solar cells, biomedicine, sensors, environments, etc. are described sequentially. Thereafter, we present the theoretic calculations and simulations of 2D materials. Finally, after concluding the current progress, we provide some personal discussions on the existing challenges and future outlooks in this rapidly developing field.展开更多
Developing low-power FETs holds significant importance in advancing logic circuits,especially as the feature size of MOSFETs approaches sub-10 nanometers.However,this has been restricted by the thermionic limitation o...Developing low-power FETs holds significant importance in advancing logic circuits,especially as the feature size of MOSFETs approaches sub-10 nanometers.However,this has been restricted by the thermionic limitation of SS,which is limited to 60 mV per decade at room temperature.Herein,we proposed a strategy that utilizes 2D semiconductors with an isolated-band feature as channels to realize subthermionic SS in MOSFETs.Through high-throughput calculations,we established a guiding principle that combines the atomic structure and orbital interaction to identify their sub-thermionic transport potential.This guides us to screen 192 candidates from the 2D material database comprising 1608 systems.Additionally,the physical relationship between the sub-thermionic transport performances and electronic structures is further revealed,which enables us to predict 15 systems with promising device performances for low-power applications with supply voltage below 0.5 V.This work opens a new way for the low-power electronics based on 2D materials and would inspire extensive interests in the experimental exploration of intrinsic steep-slope MOSFETs.展开更多
Two-dimensional semiconductors,such as MoS2 are known to be highly susceptible to diverse molecular adsorbates on the surface during fabrication,which could adversely affect device performance.To ensure high device yi...Two-dimensional semiconductors,such as MoS2 are known to be highly susceptible to diverse molecular adsorbates on the surface during fabrication,which could adversely affect device performance.To ensure high device yield,uniformity and performance,the semiconductor industry has long employed wet chemical cleaning strategies to remove undesirable surface contaminations,adsorbates,and native oxides from the surface of Si wafers.A similarly effective surface cleaning technique for two-dimensional materials has not yet been fully developed.In this study,we propose a wet chemical cleaning strategy for MoS2 by using N-methyl-2-pyrrolidone.The cleaning process not only preserves the intrinsic properties of monolayer MoS2,but also significantly improves the performance of monolayer MoS2 field-effect-transistors.Superior device on current of 12 μA·μm-1 for a channel length of 400 nm,contact resistance of 15 kΩ·μm,field-effect mobility of 15.5 cm^2·V^-1·s^-1,and the average on-off current ratio of 10^8 were successfully demonstrated.展开更多
Group-VI elemental two-dimensional(2D)materials(e.g.,tellurene(Te))have unique crystalline structures and extraordinarily physical properties.However,it still remains a great challenge to controllably grow 2D Te with ...Group-VI elemental two-dimensional(2D)materials(e.g.,tellurene(Te))have unique crystalline structures and extraordinarily physical properties.However,it still remains a great challenge to controllably grow 2D Te with good repeatability,uniformity,and highly aligned orientation using vapor growth method.Here,we design a Cu foil-assisted alloy-buffer-controlled growth method to epitaxially grow aligned single-crystalline 2D Te on an insulating mica substrate.The in-situ formation of Cu-Te alloy plays a key role on 2D Te growth,alleviating the spatial and temporal non-uniformity of precursor in conventional vapor deposition process.Through transmission electron microscopy(TEM)analysis combined with theoretical calculations,we unveil that the alignment growth of Te in the[110]direction is along the[600]direction of mica,owing to the small lattice mismatch(0.15%)and strong binding strength.This work presents a method to grow aligned high-quality 2D Te in a controllable manner.展开更多
1.INTRODUCTION Two-dimensional(2D)materials are intriguing for wide applications such as electronics,optics,energy,catalysis,and so forth,which has rapidly fueled the development of nanoscience and technology in recen...1.INTRODUCTION Two-dimensional(2D)materials are intriguing for wide applications such as electronics,optics,energy,catalysis,and so forth,which has rapidly fueled the development of nanoscience and technology in recent decades.Because of their reduced dimensionality,large specific surface area,and atomic thickness,various novel behaviors and properties emerged,though the synthesis,preparation,and modification of 2D materials remain challenging on the atomic scale.展开更多
文摘Research on two-dimensional(2D) materials has been explosively increasing in last seventeen years in varying subjects including condensed matter physics, electronic engineering, materials science, and chemistry since the mechanical exfoliation of graphene in 2004. Starting from graphene, 2D materials now have become a big family with numerous members and diverse categories. The unique structural features and physicochemical properties of 2D materials make them one class of the most appealing candidates for a wide range of potential applications. In particular, we have seen some major breakthroughs made in the field of 2D materials in last five years not only in developing novel synthetic methods and exploring new structures/properties but also in identifying innovative applications and pushing forward commercialisation. In this review, we provide a critical summary on the recent progress made in the field of 2D materials with a particular focus on last five years. After a brief backgroundintroduction, we first discuss the major synthetic methods for 2D materials, including the mechanical exfoliation, liquid exfoliation, vapor phase deposition, and wet-chemical synthesis as well as phase engineering of 2D materials belonging to the field of phase engineering of nanomaterials(PEN). We then introduce the superconducting/optical/magnetic properties and chirality of 2D materials along with newly emerging magic angle 2D superlattices. Following that, the promising applications of 2D materials in electronics, optoelectronics, catalysis, energy storage, solar cells, biomedicine, sensors, environments, etc. are described sequentially. Thereafter, we present the theoretic calculations and simulations of 2D materials. Finally, after concluding the current progress, we provide some personal discussions on the existing challenges and future outlooks in this rapidly developing field.
基金supported by the Postgraduate Research&Practice Innovation Program of Jiangsu Province(KYCX22_0428)the Training Program of the Major Research Plan of the National Natural Science Foundation of China(91964103)+3 种基金the Natural Science Foundation of Jiangsu Province(BK20180071)the Fundamental Research Funds for the Central Universities(30919011109)sponsored by Qing Lan Project of Jiangsu Province,and the Six Talent Peaks Project of Jiangsu Province(XCL-035)Research Grant Council of Hong Kong(CRS_PolyU502/22).
文摘Developing low-power FETs holds significant importance in advancing logic circuits,especially as the feature size of MOSFETs approaches sub-10 nanometers.However,this has been restricted by the thermionic limitation of SS,which is limited to 60 mV per decade at room temperature.Herein,we proposed a strategy that utilizes 2D semiconductors with an isolated-band feature as channels to realize subthermionic SS in MOSFETs.Through high-throughput calculations,we established a guiding principle that combines the atomic structure and orbital interaction to identify their sub-thermionic transport potential.This guides us to screen 192 candidates from the 2D material database comprising 1608 systems.Additionally,the physical relationship between the sub-thermionic transport performances and electronic structures is further revealed,which enables us to predict 15 systems with promising device performances for low-power applications with supply voltage below 0.5 V.This work opens a new way for the low-power electronics based on 2D materials and would inspire extensive interests in the experimental exploration of intrinsic steep-slope MOSFETs.
文摘Two-dimensional semiconductors,such as MoS2 are known to be highly susceptible to diverse molecular adsorbates on the surface during fabrication,which could adversely affect device performance.To ensure high device yield,uniformity and performance,the semiconductor industry has long employed wet chemical cleaning strategies to remove undesirable surface contaminations,adsorbates,and native oxides from the surface of Si wafers.A similarly effective surface cleaning technique for two-dimensional materials has not yet been fully developed.In this study,we propose a wet chemical cleaning strategy for MoS2 by using N-methyl-2-pyrrolidone.The cleaning process not only preserves the intrinsic properties of monolayer MoS2,but also significantly improves the performance of monolayer MoS2 field-effect-transistors.Superior device on current of 12 μA·μm-1 for a channel length of 400 nm,contact resistance of 15 kΩ·μm,field-effect mobility of 15.5 cm^2·V^-1·s^-1,and the average on-off current ratio of 10^8 were successfully demonstrated.
基金supported by the Research Grant Council of Hong Kong(No.PolyU 152053/18E)the Shenzhen Science and Technology Innovation Commission(No.JCYJ20180507183424383).
文摘Group-VI elemental two-dimensional(2D)materials(e.g.,tellurene(Te))have unique crystalline structures and extraordinarily physical properties.However,it still remains a great challenge to controllably grow 2D Te with good repeatability,uniformity,and highly aligned orientation using vapor growth method.Here,we design a Cu foil-assisted alloy-buffer-controlled growth method to epitaxially grow aligned single-crystalline 2D Te on an insulating mica substrate.The in-situ formation of Cu-Te alloy plays a key role on 2D Te growth,alleviating the spatial and temporal non-uniformity of precursor in conventional vapor deposition process.Through transmission electron microscopy(TEM)analysis combined with theoretical calculations,we unveil that the alignment growth of Te in the[110]direction is along the[600]direction of mica,owing to the small lattice mismatch(0.15%)and strong binding strength.This work presents a method to grow aligned high-quality 2D Te in a controllable manner.
基金This work was supported by the National Science Foundation of China(project nos.51872248,and 51922113)the Hong Kong Research Grant Council under the Early Career Scheme(project no.25301018)+3 种基金the Hong Kong Research Grant Council General Research Fund(project no.11300820 and 15302419)the City University of Hong Kong(project nos.9680241 and 7005259)The Hong Kong Polytechnic University(project nos.1-ZVGH and ZVRP)the Shenzhen Science,Technology and Innovation Commission(project no.JCYJ20200109110213442).
文摘1.INTRODUCTION Two-dimensional(2D)materials are intriguing for wide applications such as electronics,optics,energy,catalysis,and so forth,which has rapidly fueled the development of nanoscience and technology in recent decades.Because of their reduced dimensionality,large specific surface area,and atomic thickness,various novel behaviors and properties emerged,though the synthesis,preparation,and modification of 2D materials remain challenging on the atomic scale.