Bi2O2Se thin film could be one of the promising material candidates for the next-generation electronic and optoelectronic applications. However, the performance of Bi2O2Se thin film-based device is not fully explored ...Bi2O2Se thin film could be one of the promising material candidates for the next-generation electronic and optoelectronic applications. However, the performance of Bi2O2Se thin film-based device is not fully explored in the photodetecting area. Considering the fact that the electrical properties such as carrier mobility, work function, and energy band structure of Bi2O2Se are thickness-dependent, the in-plane Bi2O2Se homojunctions consisting of layers with different thicknesses are successfully synthesized by the chemical vapor deposition(CVD) method across the terraces on the mica substrates,where terraces are created in the mica surface layer peeling off process. In this way, effective internal electrical fields are built up along the Bi2O2Se homojunctions, exhibiting diode-like rectification behavior with an on/off ratio of 102, what is more, thus obtained photodetectors possess highly sensitive and ultrafast features, with a maximum photoresponsivity of 2.5 A/W and a lifetime of 4.8 μs. Comparing with the Bi2O2Se uniform thin films, the photo-electric conversion efficiency is greatly improved for the in-plane homojunctions.展开更多
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
Subject Code:B03 With the support of the National Natural Science Foundation of China,the research team led by Prof.Peng Hailin(彭海琳)from Peking University,reported recently on the discovery of an air-stable twodime...Subject Code:B03 With the support of the National Natural Science Foundation of China,the research team led by Prof.Peng Hailin(彭海琳)from Peking University,reported recently on the discovery of an air-stable twodimensional Bi2O2Se semiconductor with ultrahigh electron mobility,which was published in展开更多
基金Project supported by the National Natural Science Foundation of China(Grant No.61705066)the Open Fund of State Key Laboratory of Information Photonics and Optical Communications(Beijing University of Posts and Telecommunications),China(Grant No.IPOC2018B004)the National Key Research and Development Program,China(Grant No.2016YFA0202401)
文摘Bi2O2Se thin film could be one of the promising material candidates for the next-generation electronic and optoelectronic applications. However, the performance of Bi2O2Se thin film-based device is not fully explored in the photodetecting area. Considering the fact that the electrical properties such as carrier mobility, work function, and energy band structure of Bi2O2Se are thickness-dependent, the in-plane Bi2O2Se homojunctions consisting of layers with different thicknesses are successfully synthesized by the chemical vapor deposition(CVD) method across the terraces on the mica substrates,where terraces are created in the mica surface layer peeling off process. In this way, effective internal electrical fields are built up along the Bi2O2Se homojunctions, exhibiting diode-like rectification behavior with an on/off ratio of 102, what is more, thus obtained photodetectors possess highly sensitive and ultrafast features, with a maximum photoresponsivity of 2.5 A/W and a lifetime of 4.8 μs. Comparing with the Bi2O2Se uniform thin films, the photo-electric conversion efficiency is greatly improved for the in-plane homojunctions.
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.
文摘Subject Code:B03 With the support of the National Natural Science Foundation of China,the research team led by Prof.Peng Hailin(彭海琳)from Peking University,reported recently on the discovery of an air-stable twodimensional Bi2O2Se semiconductor with ultrahigh electron mobility,which was published in
