Monolayer molybdenum disulfide(MoS_(2))has emerged as one of the most promising channel materials for next-generation nanoelectronics and optoelectronics owing to its atomic thickness,dangling-bond-free flat surface,a...Monolayer molybdenum disulfide(MoS_(2))has emerged as one of the most promising channel materials for next-generation nanoelectronics and optoelectronics owing to its atomic thickness,dangling-bond-free flat surface,and high electrical quality.Currently,high-quality monolayer MoS_(2)wafers are primarily grown on sapphire substrates incompatible with conventional device fabrication,and thus transfer processes to a suitable substrate are typically required before the device can be processed.Here,we demonstrate the batch production of transfer-free MoS2 top-gate devices directly on sapphire growth substrates via step engineering.By introducing substrate steps on growth substrate sapphire,high-κdielectric layers with superior quality and uniform can be directly deposited on the epitaxially grown monolayer MoS_(2).For the substrate with a maximum step density of 100μm^(−1),the gate capacitance can reach~1.87μF∙cm^(−2),while the interface trap state density(Dit)can be as low as~7.6×10^(10)cm^(−2)∙eV^(−1).The direct deposition of high-quality dielectric layers on grown monolayer MoS2 enables the batch fabrication of top-gate devices devoid of transfer and thus excellent device yield of>96%,holding great promise for large-scale twodimensional(2D)integrated circuits.展开更多
The substitutional doping of two-dimensional(2D)transition metal dichalcogenides(TMDs) is essential for tuning their electronic and optoelectronic properties.However,conventional doping methods often suffer from the e...The substitutional doping of two-dimensional(2D)transition metal dichalcogenides(TMDs) is essential for tuning their electronic and optoelectronic properties.However,conventional doping methods often suffer from the edge enrichment by dopant atoms,particularly for rare-earth dopants with large ionic radii,owing to their tendency to migrate toward high-energy edge sites during growth.Herein,we present a seed-mediated,self-driven nucleation strategy that leverages the high surface energy of stepped sapphire substrates to pre-adsorb dopant atoms at the step edges.These sites guide the localized nucleation and incorporation of the dopants,thereby effectively suppressing edge segregation.Using this approach,we synthesized centimeter-scale monolayer Yb-doped WS_(2) films with incorporated substitutional atoms,along with other metal-doped WS_(2)films.The introduction of mid-gap states near the conduction band in monolayer Yb-doped WS_(2)films was further demonstrated by the characterization of the bound exciton emission and electronic density of states.This study broadens the pathways for the controllable synthesis of substitutional 2D materials and extends the potential for developing novel 2D optoelectronic devices.展开更多
基金supported by the National Key Research and Development Program of China(Nos.2021YFA1202900 and 2021YFA1400502)the Strategic Priority Research Program of Chinese Academy of Sciences(CAS)(No.XDB30000000)+1 种基金the National Natural Science Foundation of China(NSFC)(Nos.61888102,11834017,61734001,62122084,12274447,and 12074412)the Key-Area Research and Development Program of Guangdong Province(No.2020B0101340001).
文摘Monolayer molybdenum disulfide(MoS_(2))has emerged as one of the most promising channel materials for next-generation nanoelectronics and optoelectronics owing to its atomic thickness,dangling-bond-free flat surface,and high electrical quality.Currently,high-quality monolayer MoS_(2)wafers are primarily grown on sapphire substrates incompatible with conventional device fabrication,and thus transfer processes to a suitable substrate are typically required before the device can be processed.Here,we demonstrate the batch production of transfer-free MoS2 top-gate devices directly on sapphire growth substrates via step engineering.By introducing substrate steps on growth substrate sapphire,high-κdielectric layers with superior quality and uniform can be directly deposited on the epitaxially grown monolayer MoS_(2).For the substrate with a maximum step density of 100μm^(−1),the gate capacitance can reach~1.87μF∙cm^(−2),while the interface trap state density(Dit)can be as low as~7.6×10^(10)cm^(−2)∙eV^(−1).The direct deposition of high-quality dielectric layers on grown monolayer MoS2 enables the batch fabrication of top-gate devices devoid of transfer and thus excellent device yield of>96%,holding great promise for large-scale twodimensional(2D)integrated circuits.
基金the CAS Project for Young Scientists in Basic Research,Grant/Award Number:YSBR-054Key Research and Development and Achievement Transformation Program of Inner Mongolia Autonomous Region,Grant/Award Number:2025YFHH0119+5 种基金the National Key R&D Program of China,Grant/Award Number:2021YFA1200804the Natural Science Foundation of Jiangsu Province,Grant/Award Number:BK20210124Suzhou Basic Research Program,Grant/Award Numbers:SJC2023004,ZXL2023166Jiangsu Province Key R&D Program,Grant/Award Number:BE2023009-5National Natural Science Foundation ofChina,Grant/Award Numbers:22372193,62274175,T2325025Vacuum Interconnected Nanotech Workstation(Nano-X)of Suzhou Institute of Nanotechand Nano-bionics(SINANO)。
文摘The substitutional doping of two-dimensional(2D)transition metal dichalcogenides(TMDs) is essential for tuning their electronic and optoelectronic properties.However,conventional doping methods often suffer from the edge enrichment by dopant atoms,particularly for rare-earth dopants with large ionic radii,owing to their tendency to migrate toward high-energy edge sites during growth.Herein,we present a seed-mediated,self-driven nucleation strategy that leverages the high surface energy of stepped sapphire substrates to pre-adsorb dopant atoms at the step edges.These sites guide the localized nucleation and incorporation of the dopants,thereby effectively suppressing edge segregation.Using this approach,we synthesized centimeter-scale monolayer Yb-doped WS_(2) films with incorporated substitutional atoms,along with other metal-doped WS_(2)films.The introduction of mid-gap states near the conduction band in monolayer Yb-doped WS_(2)films was further demonstrated by the characterization of the bound exciton emission and electronic density of states.This study broadens the pathways for the controllable synthesis of substitutional 2D materials and extends the potential for developing novel 2D optoelectronic devices.
