ZnO nanoneedle/nanocolumn （NN/NC） composite films were grown via reactive electron beam evaporation （REBE） in the NH3/H2 gaseous mixture by using polycrystalline ZnO ceramic targets as source materials. The growth...ZnO nanoneedle/nanocolumn （NN/NC） composite films were grown via reactive electron beam evaporation （REBE） in the NH3/H2 gaseous mixture by using polycrystalline ZnO ceramic targets as source materials. The growth was performed at low substrate temperatures （450～500℃） without employing any metallic catalysts. As-prepared samples were then rapidly annealed in 02 ambient at a higher temperature （600℃）. Electron microscopic observations revealed the typical composite-structured morphologies of NN/NC/substrate of ZnO nanomaterials grown at 500℃. Such unique morphologies should render potential applications, for instance, as an efficient microwave absorption material utilized in the fabrication of concealed aerostat. In addition, X-ray diffraction and photoluminescence measurements showed remarkable improvement in crystal and optical qualities of ZnO NN/NC composite films after annealing.展开更多
Room-temperature(RT)terahertz(THz)detection finds widespread applications in security inspection,communication,biomedical imaging,and scientific research.However,the state-of-the-art detection strategies are still lim...Room-temperature(RT)terahertz(THz)detection finds widespread applications in security inspection,communication,biomedical imaging,and scientific research.However,the state-of-the-art detection strategies are still limited by issues such as low sensitivity,narrow response range,slow response speed,complex fabrication techniques,and difficulties in scaling up to large arrays.Here,we present a high-sensitivity,broadband-response,and high-speed RT THz detection strategy by utilizing a deep subwavelength metal–semiconductor–metal(MSM)structure.The spontaneously formed 2-dimensional electron gas(2DEG)at the CdTe/PbTe interface provides a superior transport channel characterized by high carrier concentration,low scattering,and high mobility.The synergy of the electromagnetic induced well effect formed in the MSM structure,and the efficient and rapid transport capabilities of the 2DEG channel give rise to an impressive performance improvement.The proposed 2DEG photodetector exhibits a broad frequency range from 22 to 519 GHz,an ultralow noise equivalent power of 3.0×10^(−14)W Hz^(−1/2)at 166 GHz,and a short response time of 6.7μs.This work provides an effective route for the development of high-performance RT THz detection strategies,paving the way for enhanced THz technology applications.展开更多
Broadband response is pursued in both infrared(IR)and terahertz(THz)detection technologies,which find their applications in both terrestrial and astronomical realms.Herein,we report an ultrabroadband and multiband IR/...Broadband response is pursued in both infrared(IR)and terahertz(THz)detection technologies,which find their applications in both terrestrial and astronomical realms.Herein,we report an ultrabroadband and multiband IR/THz detector based on blocked-impurity-band detecting principle.The detectors are prepared by implanting phosphorus into germanium(Ge:P),where photoresponses with a P impurity band,a self-interstitial defect band,and a vacancy-P(V-P)pair defect band are realized simultaneously.The response spectra of the detectors show ultrabroad and dual response bands in a range of 3-28μm(IR band)and 40-165μm(THz band),respectively.Additionally,a tiny mid-IR(MIR)band within 3-4.2μm is embedded in the IR band.The THz band arises from the P impurity band,whereas the IR and the MIR bands are ascribed to the two defect bands.At150 m V and 4.5 K,the peak detectivities of the three bands are obtained as 2.9×10^(12) Jones(at 3.9μm),6.8×10^(12) Jones(at 16.3μm),and 9.9×10^(12) Jones(at 116.5μm),respectively.The impressive coverage andsensitivity of the detectors are promising for applications in IR and THz detection technologies.展开更多
Ultra-shallow Si p^(+)n junctions formed by plasma doping are characterized by electrochemical capacitance-voltage(ECV).By comparing ECV results with those of secondary ion mass spectroscopy(SIMS),it is found that the...Ultra-shallow Si p^(+)n junctions formed by plasma doping are characterized by electrochemical capacitance-voltage(ECV).By comparing ECV results with those of secondary ion mass spectroscopy(SIMS),it is found that the dopant concentration profiles in heavily-doped p+layer as well as junction depths measured by ECV are in good agreement with those measured by SIMS.However,the ECV measurement of dopant concentration in the underlying lightly doped n-type substrate is significantly influenced by the upper heavily-doped layer.The ECV technique is also easy to control and reproduce.The ECV results of ultra-shallow junctions(USJ)formed by plasma doping followed by different annealing processes show that ECV is capable of reliably characterizing a Si USJ with junction depth as low as 10 nm,and dopant concentration up to 10^(21) cm^(-3).Also,its depth resolution can be as fine as 1 nm.Therefore,it shows great potential in application for characterizing USJ in the sub-65 nm technology node CMOS devices.展开更多
基金The authors gratefully acknowledge support from the National Natural Science Foundation of China under Grant No. 50472058.
文摘ZnO nanoneedle/nanocolumn （NN/NC） composite films were grown via reactive electron beam evaporation （REBE） in the NH3/H2 gaseous mixture by using polycrystalline ZnO ceramic targets as source materials. The growth was performed at low substrate temperatures （450～500℃） without employing any metallic catalysts. As-prepared samples were then rapidly annealed in 02 ambient at a higher temperature （600℃）. Electron microscopic observations revealed the typical composite-structured morphologies of NN/NC/substrate of ZnO nanomaterials grown at 500℃. Such unique morphologies should render potential applications, for instance, as an efficient microwave absorption material utilized in the fabrication of concealed aerostat. In addition, X-ray diffraction and photoluminescence measurements showed remarkable improvement in crystal and optical qualities of ZnO NN/NC composite films after annealing.
基金supported by the National Natural Science Foundation of China(11933006,61805060,U2141240,and 62175045)National Key Research and Development Project of China(2023YFB2806700)+5 种基金Zhejiang Provincial Natural Science Foundation of China(LGF21F050001)Hangzhou Science and Technology Bureau of Zhejiang Province(TD2020002)Hangzhou Key Research and Development Program(2024SZD1A39)Research Funds of Hangzhou Institute for Advanced Study(B02006C019019 and 2022ZZ01007)Zhejiang Provincial Natural Science Foundation of China(no.LD25F040001)Hangzhou Joint Fund of the Zhejiang Provincial Natural Science Foundation of China(no.LHZQN25F050001).
文摘Room-temperature(RT)terahertz(THz)detection finds widespread applications in security inspection,communication,biomedical imaging,and scientific research.However,the state-of-the-art detection strategies are still limited by issues such as low sensitivity,narrow response range,slow response speed,complex fabrication techniques,and difficulties in scaling up to large arrays.Here,we present a high-sensitivity,broadband-response,and high-speed RT THz detection strategy by utilizing a deep subwavelength metal–semiconductor–metal(MSM)structure.The spontaneously formed 2-dimensional electron gas(2DEG)at the CdTe/PbTe interface provides a superior transport channel characterized by high carrier concentration,low scattering,and high mobility.The synergy of the electromagnetic induced well effect formed in the MSM structure,and the efficient and rapid transport capabilities of the 2DEG channel give rise to an impressive performance improvement.The proposed 2DEG photodetector exhibits a broad frequency range from 22 to 519 GHz,an ultralow noise equivalent power of 3.0×10^(−14)W Hz^(−1/2)at 166 GHz,and a short response time of 6.7μs.This work provides an effective route for the development of high-performance RT THz detection strategies,paving the way for enhanced THz technology applications.
基金National Natural Science Foundation of China(11933006,61775229,61805060,61927813)Key Research and Development Program of Zhejiang Province(2020C01120)Sino-German Science Center(GZ1580)。
文摘Broadband response is pursued in both infrared(IR)and terahertz(THz)detection technologies,which find their applications in both terrestrial and astronomical realms.Herein,we report an ultrabroadband and multiband IR/THz detector based on blocked-impurity-band detecting principle.The detectors are prepared by implanting phosphorus into germanium(Ge:P),where photoresponses with a P impurity band,a self-interstitial defect band,and a vacancy-P(V-P)pair defect band are realized simultaneously.The response spectra of the detectors show ultrabroad and dual response bands in a range of 3-28μm(IR band)and 40-165μm(THz band),respectively.Additionally,a tiny mid-IR(MIR)band within 3-4.2μm is embedded in the IR band.The THz band arises from the P impurity band,whereas the IR and the MIR bands are ascribed to the two defect bands.At150 m V and 4.5 K,the peak detectivities of the three bands are obtained as 2.9×10^(12) Jones(at 3.9μm),6.8×10^(12) Jones(at 16.3μm),and 9.9×10^(12) Jones(at 116.5μm),respectively.The impressive coverage andsensitivity of the detectors are promising for applications in IR and THz detection technologies.
文摘Ultra-shallow Si p^(+)n junctions formed by plasma doping are characterized by electrochemical capacitance-voltage(ECV).By comparing ECV results with those of secondary ion mass spectroscopy(SIMS),it is found that the dopant concentration profiles in heavily-doped p+layer as well as junction depths measured by ECV are in good agreement with those measured by SIMS.However,the ECV measurement of dopant concentration in the underlying lightly doped n-type substrate is significantly influenced by the upper heavily-doped layer.The ECV technique is also easy to control and reproduce.The ECV results of ultra-shallow junctions(USJ)formed by plasma doping followed by different annealing processes show that ECV is capable of reliably characterizing a Si USJ with junction depth as low as 10 nm,and dopant concentration up to 10^(21) cm^(-3).Also,its depth resolution can be as fine as 1 nm.Therefore,it shows great potential in application for characterizing USJ in the sub-65 nm technology node CMOS devices.
