The formation of heterojunction within solid-state devices enables them with eventually high performances,but provides a challenge for material synthesis and device fabrication because strict conditions such as lattic...The formation of heterojunction within solid-state devices enables them with eventually high performances,but provides a challenge for material synthesis and device fabrication because strict conditions such as lattice match are needed.Herein,we show a facile method to fabricate a van der Waals(vdW)heterojunction between two-dimensional(2D)bismuth oxyselenide(Bi2O2Se)and graphene,during which the graphene is directly transferred to the Bi2O2Se and served as a lowcontract-resistant electrode with small work function mismatch(~50 meV).As an optoelectronic device,the Bi2O2Se/graphene vdW heterojunction allows for the efficient sensing toward 1200-nm incident laser.Regarding the application of fieldeffect transistors(FETs),the short-channel(50 nm)sample can be synthesized by utilizing these two 2D materials(ie,channel:Bi2O2Se;drain/source terminal:graphene)and the n-type characteristic can be observed with the accordant field modulation.It is confirmed that we show a simple way to prepare the vdW heterojunction which is aiming to the high-performance applications among optoelectronics and FETs.展开更多
Direct growth of large area uniform graphene on functional insulating materials is essential for engineering versatile applications of graphene. However, the existing synthesis approaches can hardly avoid the generati...Direct growth of large area uniform graphene on functional insulating materials is essential for engineering versatile applications of graphene. However, the existing synthesis approaches can hardly avoid the generation of non-uniform multilayer graphene along the gas flow direction, affording huge challenges for further scaling up. Herein, by exploiting the molten state of soda-lime glass, we have accomplished the direct growth of large area uniform (up to 30 cm × 6 cm) graphene via a facile chemical vapor deposition route on low cost soda-lime glass. The use of molten glass eliminates the chemically active sites (surface corrugations, scratches, defects), and improves the mobility of carbon precursors, affording uniform nucleation and growth of monolayer graphene. Intriguingly, thus-obtained graphene acts as an ideal coating layer for the surface crystallographic modification of soda-lime glass, making it epitaxy substrates for synthesizing high-quality PbI2 nanoplates and continues films. Accordingly, a prototype photodetector was fabricated to present excellent photoelectrical properties of high responsivity (~ 600 on/off current ratio) and fast response speed (18 μs). This work hereby paves ways for the batch production and the direct applications of graphene glass as platforms for constructing high performance electronic and optoelectronic devices.展开更多
A thorough understanding of nanoscale heat flow inheterostructures is crucial for future multifunctional na-nodevices based on 2D materials. For example, the ther-mal exchanges based on hot-carrier cooling pathways an...A thorough understanding of nanoscale heat flow inheterostructures is crucial for future multifunctional na-nodevices based on 2D materials. For example, the ther-mal exchanges based on hot-carrier cooling pathways andtime in graphene devices have been rigorously in-vestigated, and these studies provide guidance for thedevelopment of electronic and optoelectronic applications[1,2]. Furthermore, defect-assisted acoustic phononscattering [3], intrinsic optical phonon （OP） cooling [4],and interlayer Coulomb coupling [5] are the three pri-mary relaxation mechanisms in diffusive, suspended, anddecoupled multilayer graphene, respectively. However,perfect supported or encapsulated graphene, in whichelectrons are coupled to remote polar phonon modes, isdifferent from the other types of graphene mentionedabove, and it lacks sufficient experimental research.展开更多
基金support from the National Basic Research Program of China(No.2016YFA0200101)the National Natural Science Foundation of China(Nos.21733001 and 21525310)Boya Postdoctoral Fellowship.
文摘The formation of heterojunction within solid-state devices enables them with eventually high performances,but provides a challenge for material synthesis and device fabrication because strict conditions such as lattice match are needed.Herein,we show a facile method to fabricate a van der Waals(vdW)heterojunction between two-dimensional(2D)bismuth oxyselenide(Bi2O2Se)and graphene,during which the graphene is directly transferred to the Bi2O2Se and served as a lowcontract-resistant electrode with small work function mismatch(~50 meV).As an optoelectronic device,the Bi2O2Se/graphene vdW heterojunction allows for the efficient sensing toward 1200-nm incident laser.Regarding the application of fieldeffect transistors(FETs),the short-channel(50 nm)sample can be synthesized by utilizing these two 2D materials(ie,channel:Bi2O2Se;drain/source terminal:graphene)and the n-type characteristic can be observed with the accordant field modulation.It is confirmed that we show a simple way to prepare the vdW heterojunction which is aiming to the high-performance applications among optoelectronics and FETs.
基金supported by the National Basic Research Program of China (No.2016YFA0200103)the National Natural Science Foundation of China (Nos.51432002 and 51290272)the Beijing Municipal Science and Technology Planning Project (No.Z161100002116020).
文摘Direct growth of large area uniform graphene on functional insulating materials is essential for engineering versatile applications of graphene. However, the existing synthesis approaches can hardly avoid the generation of non-uniform multilayer graphene along the gas flow direction, affording huge challenges for further scaling up. Herein, by exploiting the molten state of soda-lime glass, we have accomplished the direct growth of large area uniform (up to 30 cm × 6 cm) graphene via a facile chemical vapor deposition route on low cost soda-lime glass. The use of molten glass eliminates the chemically active sites (surface corrugations, scratches, defects), and improves the mobility of carbon precursors, affording uniform nucleation and growth of monolayer graphene. Intriguingly, thus-obtained graphene acts as an ideal coating layer for the surface crystallographic modification of soda-lime glass, making it epitaxy substrates for synthesizing high-quality PbI2 nanoplates and continues films. Accordingly, a prototype photodetector was fabricated to present excellent photoelectrical properties of high responsivity (~ 600 on/off current ratio) and fast response speed (18 μs). This work hereby paves ways for the batch production and the direct applications of graphene glass as platforms for constructing high performance electronic and optoelectronic devices.
文摘A thorough understanding of nanoscale heat flow inheterostructures is crucial for future multifunctional na-nodevices based on 2D materials. For example, the ther-mal exchanges based on hot-carrier cooling pathways andtime in graphene devices have been rigorously in-vestigated, and these studies provide guidance for thedevelopment of electronic and optoelectronic applications[1,2]. Furthermore, defect-assisted acoustic phononscattering [3], intrinsic optical phonon （OP） cooling [4],and interlayer Coulomb coupling [5] are the three pri-mary relaxation mechanisms in diffusive, suspended, anddecoupled multilayer graphene, respectively. However,perfect supported or encapsulated graphene, in whichelectrons are coupled to remote polar phonon modes, isdifferent from the other types of graphene mentionedabove, and it lacks sufficient experimental research.
