In the present work,a nanoporous ZnO/n-Si structure has been proposed as a new type infrared photodetector.Triggered by one laser pulse with wavelength of 1064 nm,this structure exhibits a double-peak decay of transie...In the present work,a nanoporous ZnO/n-Si structure has been proposed as a new type infrared photodetector.Triggered by one laser pulse with wavelength of 1064 nm,this structure exhibits a double-peak decay of transient photovoltage.Also,the time interval between these two peaks increases linearly with the increase of irradiated pulsed energy,indicating the promising application of this hetero-junction in photo-energy detection of infrared pulsed laser.A possible mechanism for this particular photoresponse has been discussed.展开更多
Fine structured multiple-harmonic electromagnetic emissions at frequencies around the equatorial oxygen cyclotron harmonics are observed by Van Allen Probe A outside the core plasmasphere(L^5) off the magnetic equator...Fine structured multiple-harmonic electromagnetic emissions at frequencies around the equatorial oxygen cyclotron harmonics are observed by Van Allen Probe A outside the core plasmasphere(L^5) off the magnetic equator(MLAT~.7.5°)during a geomagnetic storm. We find that the multiple-harmonic emissions have power spectrum density(PSD) peaks during 2–8equatorial oxygen gyroharmonics( f ~ n fO+, n=2–8), while the fundamental mode(n=1) is absent, implying that the harmonic waves are generated near the equator and propagate into the observation region. Additionally, these electromagnetic emissions are linearly polarized. Different from the equatorial noise emission that propagates considerably obliquely, these emissions have moderate wave normal angles(approximately 40°–60°), which predominately increase as the harmonic number increases.Considering their frequency and wave normal angle characteristics, it is suggested that these multiple-harmonic emissions play an important role in the dynamic variation of radiation belt electrons.展开更多
Vertically aligned TiO2nanorods arrays were successfully synthesized on FTO glass by wet-chemical method.Based on polystyrene sulfate(PSS)functionalized TiO2nanorods arrays,a sandwich-structured hybrid UV photodetecto...Vertically aligned TiO2nanorods arrays were successfully synthesized on FTO glass by wet-chemical method.Based on polystyrene sulfate(PSS)functionalized TiO2nanorods arrays,a sandwich-structured hybrid UV photodetector was fabricated.The photo-to-dark current ratio of the device increases by more than 3 orders of magnitude with typical case,while the dark current is about 10 nA at 1 V bias.The high photoresponse together with the low dark current could probably contribute a large photocurrent and low-power application.The high performance of the hybrid material and facile low-cost fabrication of the UV detector make the devices promising for large-area UV photodetection applications.展开更多
We report fabrication and characterization of metal-semiconductor-metal photoconductive detectors based on Al-doped ZnO thin films fabricated by radio frequency magnetron sputtering.Optical and structural properties o...We report fabrication and characterization of metal-semiconductor-metal photoconductive detectors based on Al-doped ZnO thin films fabricated by radio frequency magnetron sputtering.Optical and structural properties of the thin films were characterized using various techniques.At 6 V bias,a responsivity higher than 4 A/W in the wavelength shorter than 350 nm was obtained,and this responsibility dropped quickly and reached the noise floor in the visible region.Transient response measurement revealed that the detector had a fast photoresponse with a rise time of 9 ns and a fall time of 1.2 μs.展开更多
Flexible and broadband photodetectors have drawn extensive attention due to their potential application in foldable displays, optical communications, environmental monitoring, etc. In this work, a flexible photodetect...Flexible and broadband photodetectors have drawn extensive attention due to their potential application in foldable displays, optical communications, environmental monitoring, etc. In this work, a flexible photodetector based on the crystalline PbS quantum dots(QDs)/ZnO nanoparticles(NPs) heterostructure was proposed. The photodetector exhibits a broadband response from ultraviolet-visible(UV-Vis)to near infrared detector(NIR) range with a remarkable current on/off ratio of 7.08×10^3under 375 nm light illumination.Compared with pure ZnO NPs, the heterostructure photodetector shows the three orders of magnitude higher responsivity in Vis and NIR range, and maintains its performance in the UV range simultaneously. The photodetector demonstrates a high responsivity and detectivity of4.54 A W-1and 3.98×10^12Jones. In addition, the flexible photodetectors exhibit excellent durability and stability even after hundreds of times bending. This work paves a promising way for constructing next-generation high-performance flexible and broadband optoelectronic devices.展开更多
基金supported by the National Key Basic Research Program of China (Grant No. 2014CB744300)the Specially Funded Program on National Key Scientific Instruments and Equipment Development (GrantNo. 2012YQ140005)+1 种基金the Beijing National Science Foundation (Grant No. 4122064)the Science Foundation of the China University of Petroleum (Beijing)
文摘In the present work,a nanoporous ZnO/n-Si structure has been proposed as a new type infrared photodetector.Triggered by one laser pulse with wavelength of 1064 nm,this structure exhibits a double-peak decay of transient photovoltage.Also,the time interval between these two peaks increases linearly with the increase of irradiated pulsed energy,indicating the promising application of this hetero-junction in photo-energy detection of infrared pulsed laser.A possible mechanism for this particular photoresponse has been discussed.
基金supported by the National Natural Science Foundation of China (Grant Nos. 41374168, 41521063 & 41174140)Key Grant Project of Chinese Ministry of Education (Grant No. 2042015KF0169)Program for New Century Excellent Talents in University (Grant No. NCET-13-0446)
文摘Fine structured multiple-harmonic electromagnetic emissions at frequencies around the equatorial oxygen cyclotron harmonics are observed by Van Allen Probe A outside the core plasmasphere(L^5) off the magnetic equator(MLAT~.7.5°)during a geomagnetic storm. We find that the multiple-harmonic emissions have power spectrum density(PSD) peaks during 2–8equatorial oxygen gyroharmonics( f ~ n fO+, n=2–8), while the fundamental mode(n=1) is absent, implying that the harmonic waves are generated near the equator and propagate into the observation region. Additionally, these electromagnetic emissions are linearly polarized. Different from the equatorial noise emission that propagates considerably obliquely, these emissions have moderate wave normal angles(approximately 40°–60°), which predominately increase as the harmonic number increases.Considering their frequency and wave normal angle characteristics, it is suggested that these multiple-harmonic emissions play an important role in the dynamic variation of radiation belt electrons.
基金supported by the National Science Fund for Distinguished Young Scholars of China(Grant No.21125628)Young Scientists Fund of the National Natural Science Foundation of China(Grant No.21006008)
文摘Vertically aligned TiO2nanorods arrays were successfully synthesized on FTO glass by wet-chemical method.Based on polystyrene sulfate(PSS)functionalized TiO2nanorods arrays,a sandwich-structured hybrid UV photodetector was fabricated.The photo-to-dark current ratio of the device increases by more than 3 orders of magnitude with typical case,while the dark current is about 10 nA at 1 V bias.The high photoresponse together with the low dark current could probably contribute a large photocurrent and low-power application.The high performance of the hybrid material and facile low-cost fabrication of the UV detector make the devices promising for large-area UV photodetection applications.
基金supported by the National Natural Science Foundation of China (Grant No.50972007)the Beijing Municipal Natural Science Foundation (Grant No.4092035)+3 种基金the State Key Program for Basic Research of the Ministry of Science and Technology of China (Grant No.2011CB932703)the Special Items Fund of Beijing Municipal Commission of Educationthe Opened Fund of State Key Laboratory on Integrated Optoelectronicsthe National Science Fund for Distinguished Young Scholars (Grant No.60825407)
文摘We report fabrication and characterization of metal-semiconductor-metal photoconductive detectors based on Al-doped ZnO thin films fabricated by radio frequency magnetron sputtering.Optical and structural properties of the thin films were characterized using various techniques.At 6 V bias,a responsivity higher than 4 A/W in the wavelength shorter than 350 nm was obtained,and this responsibility dropped quickly and reached the noise floor in the visible region.Transient response measurement revealed that the detector had a fast photoresponse with a rise time of 9 ns and a fall time of 1.2 μs.
基金funded by the National Natural Science Foundation of China (U1432249)the National Key R&D Program of China (2017YFA0205002)+3 种基金the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD)supported by Collaborative Innovation Center of Suzhou Nano Science & Technology and Joint International Research Laboratory of Carbon-Based Functional Materials and Devicesthe support from China Postdoctoral Science Foundation (2017M610346)Natural Science Foundation of Jiangsu Province of China (BK20170343)
文摘Flexible and broadband photodetectors have drawn extensive attention due to their potential application in foldable displays, optical communications, environmental monitoring, etc. In this work, a flexible photodetector based on the crystalline PbS quantum dots(QDs)/ZnO nanoparticles(NPs) heterostructure was proposed. The photodetector exhibits a broadband response from ultraviolet-visible(UV-Vis)to near infrared detector(NIR) range with a remarkable current on/off ratio of 7.08×10^3under 375 nm light illumination.Compared with pure ZnO NPs, the heterostructure photodetector shows the three orders of magnitude higher responsivity in Vis and NIR range, and maintains its performance in the UV range simultaneously. The photodetector demonstrates a high responsivity and detectivity of4.54 A W-1and 3.98×10^12Jones. In addition, the flexible photodetectors exhibit excellent durability and stability even after hundreds of times bending. This work paves a promising way for constructing next-generation high-performance flexible and broadband optoelectronic devices.
