Heterostructures from mechanically-assembled stacks of two-dimensional materials allow for versatile electronic device applications.Here,we demonstrate the intrinsic charge transport behaviors in graphene-black phosph...Heterostructures from mechanically-assembled stacks of two-dimensional materials allow for versatile electronic device applications.Here,we demonstrate the intrinsic charge transport behaviors in graphene-black phosphorus heterojunction devices under different charge carrier densities and temperature regimes.At high carder densities or in the ON state,tunneling through the Schottky barrier at the interface between graphene and black phosphorus dominates at low temperatures.With temperature increasing,the Schottky barrier at the interface is vanishing,and the channel current starts to decrease with increasing temperature,behaving like a metal.While at low carder densities or in the OFF state,thermal emission over the Schottky barrier at the interface dominates the carriers transport process.A barrier height of~67.3 meV can be extracted from the thermal emission-diffusion theory.展开更多
We report a novel two-step ambient pressure chemical vapor deposition(CVD)pathway to grow high-quality Mo S_(2)monolayer on the Si O_(2)substrate with large crystal size up to 110μm.The large specific surface area of...We report a novel two-step ambient pressure chemical vapor deposition(CVD)pathway to grow high-quality Mo S_(2)monolayer on the Si O_(2)substrate with large crystal size up to 110μm.The large specific surface area of the pre-synthesized Mo O_(3)flakes on the mica substrate compared to Mo O_(3)powder could dramatically reduce the consumption of the Mo source.The electronic information inferred from the four-probe scanning tunneling microscope(4P-STM)image explains the threshold voltage variations and the n-type behavior observed in the two-terminal transport measurements.Furthermore,the direct van der Pauw transport also confirms its relatively high carrier mobility.Our study provides a reliable method to synthesize high-quality Mo S_(2)monolayer,which is confirmed by the direct 4P-STM measurement results.Such methodology is a key step toward the large-scale growth of transition metal dichalcogenides(TMDs)on the Si O_(2)substrate and is essential to further development of the TMDs-related integrated devices.展开更多
Atom tracking technology enhanced with innovative algorithms has been implemented in this study,utilizing a comprehensive suite of controllers and software independently developed domestically.Leveraging an on-board f...Atom tracking technology enhanced with innovative algorithms has been implemented in this study,utilizing a comprehensive suite of controllers and software independently developed domestically.Leveraging an on-board field-programmable gate array(FPGA)with a core frequency of 100 MHz,our system facilitates reading and writing operations across 16 channels,performing discrete incremental proportional-integral-derivative(PID)calculations within 3.4 microseconds.Building upon this foundation,gradient and extremum algorithms are further integrated,incorporating circular and spiral scanning modes with a horizontal movement accuracy of 0.38 pm.This integration enhances the real-time performance and significantly increases the accuracy of atom tracking.Atom tracking achieves an equivalent precision of at least 142 pm on a highly oriented pyrolytic graphite(HOPG)surface under room temperature atmospheric conditions.Through applying computer vision and image processing algorithms,atom tracking can be used when scanning a large area.The techniques primarily consist of two algorithms:the region of interest(ROI)-based feature matching algorithm,which achieves 97.92%accuracy,and the feature description-based matching algorithm,with an impressive 99.99%accuracy.Both implementation approaches have been tested for scanner drift measurements,and these technologies are scalable and applicable in various domains of scanning probe microscopy with broad application prospects in the field of nanoengineering.展开更多
基金Project supported by the National Basic Research Program of China(Grant No.2013CBA01600)the National Key Research&Development Project of China(Grant No.2016YFA0202300)+2 种基金the National Natural Science Foundation of China(Grant Nos.61474141,61674170,61335006,61390501,51325204,and51210003)Youth Innovation Promotion Association of Chinese Academy of Sciences(Grant No.20150005)the China Postdoctoral Science Foundation(Grant No.2017M623146)
文摘Heterostructures from mechanically-assembled stacks of two-dimensional materials allow for versatile electronic device applications.Here,we demonstrate the intrinsic charge transport behaviors in graphene-black phosphorus heterojunction devices under different charge carrier densities and temperature regimes.At high carder densities or in the ON state,tunneling through the Schottky barrier at the interface between graphene and black phosphorus dominates at low temperatures.With temperature increasing,the Schottky barrier at the interface is vanishing,and the channel current starts to decrease with increasing temperature,behaving like a metal.While at low carder densities or in the OFF state,thermal emission over the Schottky barrier at the interface dominates the carriers transport process.A barrier height of~67.3 meV can be extracted from the thermal emission-diffusion theory.
基金Project supported by the National Natural Science Foundation of China(Grant No.61888102)the National Natural Science Foundation of China(Grant No.12004417)+5 种基金the National Key Research and Development Program of China(Grant Nos.2018YFA0305800 and 2019YFA0308500)the National Natural Science Foundation of China(Grant No.U2032206)Chinese Academy of Sciences(Grant Nos.XDB36000000,YSBR-003,and 112111KYSB20160061)Strategic Priority Research Program of Chinese Academy of Sciences(CAS)(Grant Nos.XDB30000000 and XDB28000000)Youth Innovation Promotion Association of CAS(Grant No.Y201902)CAS Project for Young Scientists in Basic Research(Grant No.YSBR-003)。
文摘We report a novel two-step ambient pressure chemical vapor deposition(CVD)pathway to grow high-quality Mo S_(2)monolayer on the Si O_(2)substrate with large crystal size up to 110μm.The large specific surface area of the pre-synthesized Mo O_(3)flakes on the mica substrate compared to Mo O_(3)powder could dramatically reduce the consumption of the Mo source.The electronic information inferred from the four-probe scanning tunneling microscope(4P-STM)image explains the threshold voltage variations and the n-type behavior observed in the two-terminal transport measurements.Furthermore,the direct van der Pauw transport also confirms its relatively high carrier mobility.Our study provides a reliable method to synthesize high-quality Mo S_(2)monolayer,which is confirmed by the direct 4P-STM measurement results.Such methodology is a key step toward the large-scale growth of transition metal dichalcogenides(TMDs)on the Si O_(2)substrate and is essential to further development of the TMDs-related integrated devices.
基金Project supported by the National Science Fund for Distinguished Young Scholars(Grant No.T2125014)the Special Fund for Research on National Major Research Instruments of the National Natural Science Foundation of China(Grant No.11927808)the CAS Key Technology Research and Development Team Project(Grant No.GJJSTD20200005)。
文摘Atom tracking technology enhanced with innovative algorithms has been implemented in this study,utilizing a comprehensive suite of controllers and software independently developed domestically.Leveraging an on-board field-programmable gate array(FPGA)with a core frequency of 100 MHz,our system facilitates reading and writing operations across 16 channels,performing discrete incremental proportional-integral-derivative(PID)calculations within 3.4 microseconds.Building upon this foundation,gradient and extremum algorithms are further integrated,incorporating circular and spiral scanning modes with a horizontal movement accuracy of 0.38 pm.This integration enhances the real-time performance and significantly increases the accuracy of atom tracking.Atom tracking achieves an equivalent precision of at least 142 pm on a highly oriented pyrolytic graphite(HOPG)surface under room temperature atmospheric conditions.Through applying computer vision and image processing algorithms,atom tracking can be used when scanning a large area.The techniques primarily consist of two algorithms:the region of interest(ROI)-based feature matching algorithm,which achieves 97.92%accuracy,and the feature description-based matching algorithm,with an impressive 99.99%accuracy.Both implementation approaches have been tested for scanner drift measurements,and these technologies are scalable and applicable in various domains of scanning probe microscopy with broad application prospects in the field of nanoengineering.
