In situ angle dispersive synchrotron X-ray diffraction and Raman scattering measurements under pressure are em- ployed to study the structural evolution of Cu4Bi4S9 nanoribbons, which are fabricated by using a facile ...In situ angle dispersive synchrotron X-ray diffraction and Raman scattering measurements under pressure are em- ployed to study the structural evolution of Cu4Bi4S9 nanoribbons, which are fabricated by using a facile solvothermal method. Both experiments show that a structural phase transition occurs near 14.5 GPa, and there is a pressure-induced re- versible amorphization at about 25.6 GPa. The electrical transport property of a single Cu4Bi4S9 nanoribbon under different pressures is also investigated.展开更多
Low-dimensional semiconductors with in-plane anisotropy and narrow bandgap have been extensively applied to polarized detection in the near-infrared(NIR)region.However,the narrow bandgap can cause noise owing to the h...Low-dimensional semiconductors with in-plane anisotropy and narrow bandgap have been extensively applied to polarized detection in the near-infrared(NIR)region.However,the narrow bandgap can cause noise owing to the high dark current in photodetectors.This article reports quasi-1D ZrGeTe_(4)nanoribbonbased photodetectors with low dark current and broadband polarization detection.The photodetector was fabricated by evaporating 50-nm-thick Au electrodes on a ZrGeTe_(4)nanoribbon.Benefiting from the photovoltaic characteristics in the ZrGeTe_(4)nanoribbon and Au electrodes,these photodetectors can operate without bias voltage,with decreased dark current,and improved device performance.Furthermore,the quasi-1D ZrGeTe_(4)nanoribbon-based photodetectors demonstrate a polarization sensitivity in a broadband from visible(VIS)to the NIR region,such as a high photoresponsivity of 625.65 mA W1,large external quantum efficiency of 145.9%at 532 nm,and photocurrent anisotropy ratio of 2.04 at 1064 nm.They exhibit a novel perpendicular optical reversal of 90in polarization-sensitive photodetection,angle-resolved absorption spectra,and azimuth-dependent reflectance difference microscopy(ADRDM)from VIS to the NIR region,as opposed to other nanoribbon-based polarization-sensitive photodetectors.This work paves the way for utilizing photovoltaic photodetectors based on low-dimensional materials for broad-spectrum polarized photodetection.展开更多
As one of the important materials,nanocrystalline Au(n-Au)has gained numerous interests in recent decades owing to its unique properties and promising applications.However,most of the current n-Au thin films are suppo...As one of the important materials,nanocrystalline Au(n-Au)has gained numerous interests in recent decades owing to its unique properties and promising applications.However,most of the current n-Au thin films are supported on substrates,limiting the study on their mechanical properties and applications.Therefore,it is urgently desired to develop a new strategy to prepare nAu materials with superior mechanical strength and hardness.Here,a hard n-Au material with an average grain size of~40 nm is prepared by cold-forging of the unique Au nanoribbons(NRBs)with unconventional 4H phase under high pressure.Systematic characterizations reveal the phase transformation from 4H to face-centered cubic(fcc)phase during the cold compression.Impressively,the compressive yield strength and Vickers hardness(HV)of the prepared n-Au material reach~140.2 MPa and~1.0 GPa,which are 4.2 and 2.2 times of the microcrystalline Au foil,respectively.This work demonstrates that the combination of high-pressure cold-forging and the in-situ 4H-to-fcc phase transformation can effectively inhibit the grain growth in the obtained n-Au materials,leading to the formation of novel hard n-Au materials.Our strategy opens up a new avenue for the preparation of nanocrystalline metals with superior mechanical property.展开更多
基金Project supported by the National Basic Research Program of China(Grant No.2012CB932302)the National Natural Science Foundation of China(Grant No.11174336)
文摘In situ angle dispersive synchrotron X-ray diffraction and Raman scattering measurements under pressure are em- ployed to study the structural evolution of Cu4Bi4S9 nanoribbons, which are fabricated by using a facile solvothermal method. Both experiments show that a structural phase transition occurs near 14.5 GPa, and there is a pressure-induced re- versible amorphization at about 25.6 GPa. The electrical transport property of a single Cu4Bi4S9 nanoribbon under different pressures is also investigated.
基金Pearl River Talent Recruitment Program,Grant/Award Numbers:2019ZT08X639,2017YFA0207500CAS-JSPS Cooperative Research Project,Grant/Award Number:GJHZ2021131+2 种基金Strategic Priority Research Program of the Chinese Academy of Sciences,Grant/Award Number:XDB43000000National Key Research and Development Program of ChinaNational Natural Science Foundation of China,Grant/Award Numbers:12004375,62004193。
文摘Low-dimensional semiconductors with in-plane anisotropy and narrow bandgap have been extensively applied to polarized detection in the near-infrared(NIR)region.However,the narrow bandgap can cause noise owing to the high dark current in photodetectors.This article reports quasi-1D ZrGeTe_(4)nanoribbonbased photodetectors with low dark current and broadband polarization detection.The photodetector was fabricated by evaporating 50-nm-thick Au electrodes on a ZrGeTe_(4)nanoribbon.Benefiting from the photovoltaic characteristics in the ZrGeTe_(4)nanoribbon and Au electrodes,these photodetectors can operate without bias voltage,with decreased dark current,and improved device performance.Furthermore,the quasi-1D ZrGeTe_(4)nanoribbon-based photodetectors demonstrate a polarization sensitivity in a broadband from visible(VIS)to the NIR region,such as a high photoresponsivity of 625.65 mA W1,large external quantum efficiency of 145.9%at 532 nm,and photocurrent anisotropy ratio of 2.04 at 1064 nm.They exhibit a novel perpendicular optical reversal of 90in polarization-sensitive photodetection,angle-resolved absorption spectra,and azimuth-dependent reflectance difference microscopy(ADRDM)from VIS to the NIR region,as opposed to other nanoribbon-based polarization-sensitive photodetectors.This work paves the way for utilizing photovoltaic photodetectors based on low-dimensional materials for broad-spectrum polarized photodetection.
基金supported by the National Natural Science Foundation of China(Nos.52090020,51722209,and 51525205)the National Key Research and Development Program of China(No.2018YFA0305900)+3 种基金Z.S.Z.acknowledges the NSF for Distinguished Young Scholars of Hebei Province of China(No.E2018203349)M.D.M.acknowledges the China Postdoctoral Science Foundation(No.2021M691051)Z.X.F.and H.Z.thank the support from ITC via Hong Kong Branch of National Precious Metals Material Engineering Research Center(NPMM),the Start-Up Grants(Nos.9380100,9610480,and 7200651)grants(Nos.9610478,1886921,7020013,and 7005512)from City University of Hong Kong.
文摘As one of the important materials,nanocrystalline Au(n-Au)has gained numerous interests in recent decades owing to its unique properties and promising applications.However,most of the current n-Au thin films are supported on substrates,limiting the study on their mechanical properties and applications.Therefore,it is urgently desired to develop a new strategy to prepare nAu materials with superior mechanical strength and hardness.Here,a hard n-Au material with an average grain size of~40 nm is prepared by cold-forging of the unique Au nanoribbons(NRBs)with unconventional 4H phase under high pressure.Systematic characterizations reveal the phase transformation from 4H to face-centered cubic(fcc)phase during the cold compression.Impressively,the compressive yield strength and Vickers hardness(HV)of the prepared n-Au material reach~140.2 MPa and~1.0 GPa,which are 4.2 and 2.2 times of the microcrystalline Au foil,respectively.This work demonstrates that the combination of high-pressure cold-forging and the in-situ 4H-to-fcc phase transformation can effectively inhibit the grain growth in the obtained n-Au materials,leading to the formation of novel hard n-Au materials.Our strategy opens up a new avenue for the preparation of nanocrystalline metals with superior mechanical property.
