Bi_(2)YbO_(4)Cl with a fluorite layer structure belongs to the family of the bismuth rare-earth oxyhalides Bi_(2)REO_(4)X(X=Cl,B r,I).However,the synthesis and photoelectric properties of Bi_(2)YbO_(4)Cl have almost n...Bi_(2)YbO_(4)Cl with a fluorite layer structure belongs to the family of the bismuth rare-earth oxyhalides Bi_(2)REO_(4)X(X=Cl,B r,I).However,the synthesis and photoelectric properties of Bi_(2)YbO_(4)Cl have almost not been reported.In this work,Bi_(2)YbO_(4)Cl was synthesized using the solid-state method and the solvothermal method.Yb3+ions show a strong characteristic absorption peak at 980 nm,which was measured by ultraviolet-visible-near-infrared absorption spectra.The transient photoconductivity of Bi_(2)YbO_(4)Cl was obtained by time-resolved terahertz spectroscopy system under 400 and 800 nm laser excitations,respectively.The frequency-dependent transient photoconductivity analysis reveals the Drude-Smith behavior in Bi_(2)YbO_(4)Cl.Under photoexcitation,the hot charge carriers with a long relaxation lifetime and a carrier mobility of 48 cm^(2)/(V·s) are obtained.The synthesis of Bi_(2)YbO_(4)Cl is of great significance for the development of novel photocatalytic and photo harvesting materials with broad spectral response.展开更多
Dynamically engineering the optical and electrical properties in two-dimensional(2D)materials is of great signifcance for designing the related functions and applications.The introduction of foreign-atoms has previous...Dynamically engineering the optical and electrical properties in two-dimensional(2D)materials is of great signifcance for designing the related functions and applications.The introduction of foreign-atoms has previously been proven to be a feasible way to tune the band structure and related properties of 3D materials;however,this approach still remains to be explored in 2D materials.Here,we systematically demonstrate the growth of vanadium-doped molybdenum disulfde(V-doped MoS_(2))monolayers via an alkali metal-assisted chemical vapor deposition method.Scanning transmission electron microscopy demonstrated that V atoms substituted the Mo atoms and became uniformly distributed in the MoS_(2)monolayers.This was also confrmed by Raman and X-ray photoelectron spectroscopy.Power-dependent photoluminescence spectra clearly revealed the enhanced B-exciton emission characteristics in the V-doped MoS_(2)monolayers(with low doping concentration).Most importantly,through temperature-dependent study,we observed efcient valley scattering of the B-exciton,greatly enhancing its emission intensity.Carrier transport experiments indicated that typical p-type conduction gradually arisen and was enhanced with increasing V composition in the V-doped MoS_(2),where a clear n-type behavior transited frst to ambipolar and then to lightly p-type charge carrier transport.In addition,visible to infrared wide-band photodetectors based on V-doped MoS_(2)monolayers(with low doping concentration)were demonstrated.The V-doped MoS_(2)monolayers with distinct B-exciton emission,enhanced p-type conduction and broad spectral response can provide new platforms for probing new physics and ofer novel materials for optoelectronic applications.展开更多
Si-based optical position-sensitive detectors(PSDs)have stimulated the interest of researchers due to their wide range of practical applications.However,due to the rigidity and fragility of Si crystals,the application...Si-based optical position-sensitive detectors(PSDs)have stimulated the interest of researchers due to their wide range of practical applications.However,due to the rigidity and fragility of Si crystals,the applications of flexible PSDs have been limited.Therefore,we presented a flexible broadband PSD based on a WS_(2)/Si heterostructure for the first time.A scalable sputtering method was used to deposit WS_(2)thin films onto the etched ultrathin crystalline Si surface.The fabricated flexible PSD device has a broad spectral response in the wavelength range of 450-1350 nm,with a high position sensitivity of~539.8 mV·mm^(−1)and a fast response of 2.3μs,thanks to the strong light absorption,the built-in electrical field at the WS_(2)/Si interface,and facilitated transport.Furthermore,mechanical-bending tests revealed that after 200 mechanical-bending cycles,the WS_(2)/Si PSDs have excellent mechanical flexibility,stability,and durability,demonstrating the great potential in wearable PSDs with competitive performance.展开更多
基金Project supported by the National Natural Science Foundation of China (61988102)the Key-Area Research and Development Program of Guangdong Province(2019B090917007)the Science and Technology Planning Project of Guangdong Province (2019B090909011)。
文摘Bi_(2)YbO_(4)Cl with a fluorite layer structure belongs to the family of the bismuth rare-earth oxyhalides Bi_(2)REO_(4)X(X=Cl,B r,I).However,the synthesis and photoelectric properties of Bi_(2)YbO_(4)Cl have almost not been reported.In this work,Bi_(2)YbO_(4)Cl was synthesized using the solid-state method and the solvothermal method.Yb3+ions show a strong characteristic absorption peak at 980 nm,which was measured by ultraviolet-visible-near-infrared absorption spectra.The transient photoconductivity of Bi_(2)YbO_(4)Cl was obtained by time-resolved terahertz spectroscopy system under 400 and 800 nm laser excitations,respectively.The frequency-dependent transient photoconductivity analysis reveals the Drude-Smith behavior in Bi_(2)YbO_(4)Cl.Under photoexcitation,the hot charge carriers with a long relaxation lifetime and a carrier mobility of 48 cm^(2)/(V·s) are obtained.The synthesis of Bi_(2)YbO_(4)Cl is of great significance for the development of novel photocatalytic and photo harvesting materials with broad spectral response.
基金supported by the National Key R&D Program of China(No.2022YFA1204300)the National Natural Science Foundation of China(Grant Nos.62104066,52372146,U22A20138,52221001 and 62090035)+2 种基金the Open Project Program of Wuhan National Laboratory for Optoelectronics(No.2020WNLOKF016)the Science and Technology Innovation Program of Hunan Province(Nos.2021RC3061 and 2020RC2028)the National Postdoctoral Program for Innovative Talents(No.BX2021094).
文摘Dynamically engineering the optical and electrical properties in two-dimensional(2D)materials is of great signifcance for designing the related functions and applications.The introduction of foreign-atoms has previously been proven to be a feasible way to tune the band structure and related properties of 3D materials;however,this approach still remains to be explored in 2D materials.Here,we systematically demonstrate the growth of vanadium-doped molybdenum disulfde(V-doped MoS_(2))monolayers via an alkali metal-assisted chemical vapor deposition method.Scanning transmission electron microscopy demonstrated that V atoms substituted the Mo atoms and became uniformly distributed in the MoS_(2)monolayers.This was also confrmed by Raman and X-ray photoelectron spectroscopy.Power-dependent photoluminescence spectra clearly revealed the enhanced B-exciton emission characteristics in the V-doped MoS_(2)monolayers(with low doping concentration).Most importantly,through temperature-dependent study,we observed efcient valley scattering of the B-exciton,greatly enhancing its emission intensity.Carrier transport experiments indicated that typical p-type conduction gradually arisen and was enhanced with increasing V composition in the V-doped MoS_(2),where a clear n-type behavior transited frst to ambipolar and then to lightly p-type charge carrier transport.In addition,visible to infrared wide-band photodetectors based on V-doped MoS_(2)monolayers(with low doping concentration)were demonstrated.The V-doped MoS_(2)monolayers with distinct B-exciton emission,enhanced p-type conduction and broad spectral response can provide new platforms for probing new physics and ofer novel materials for optoelectronic applications.
基金supported by the National Natural Science Foundation of China(No.51972341)the Shandong Natural Science Foundation,China(No.ZR2020MA069).
文摘Si-based optical position-sensitive detectors(PSDs)have stimulated the interest of researchers due to their wide range of practical applications.However,due to the rigidity and fragility of Si crystals,the applications of flexible PSDs have been limited.Therefore,we presented a flexible broadband PSD based on a WS_(2)/Si heterostructure for the first time.A scalable sputtering method was used to deposit WS_(2)thin films onto the etched ultrathin crystalline Si surface.The fabricated flexible PSD device has a broad spectral response in the wavelength range of 450-1350 nm,with a high position sensitivity of~539.8 mV·mm^(−1)and a fast response of 2.3μs,thanks to the strong light absorption,the built-in electrical field at the WS_(2)/Si interface,and facilitated transport.Furthermore,mechanical-bending tests revealed that after 200 mechanical-bending cycles,the WS_(2)/Si PSDs have excellent mechanical flexibility,stability,and durability,demonstrating the great potential in wearable PSDs with competitive performance.
