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991.
Harvesting the available forms of energies in the environment to create self‐powered nanosystems is now becoming a technological reality. Self‐powered nanodevices and nanosystems are expected to play a crucial role in the future development of nanotechnology because of their specific role in fundamental studies and nanotechnological applications, mainly due to their size‐dependent properties and independent, sustainable, maintainance‐free operation. As a new field in self‐powered nanotechnology‐related research, self‐powered photodetectors have been developed which exhibit a much faster photoresponse and higher photosensitivity than the conventional photoconductor‐based photodetectors. Herein, the energy‐havesting techniques are discussed and their prospects for application in self‐powered photodetectors are summarized. Moreover, potential future directions of this research area are highlighted. 相似文献
992.
Near‐Infrared Light Photovoltaic Detector Based on GaAs Nanocone Array/Monolayer Graphene Schottky Junction
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Lin‐Bao Luo Jing‐Jing Chen Ming‐Zheng Wang Han Hu Chun‐Yan Wu Qiang Li Li Wang Jian‐An Huang Feng‐Xia Liang 《Advanced functional materials》2014,24(19):2794-2800
Near infrared light photodiodes have been attracting increasing research interest due to their wide application in various fields. In this study, the fabrication of a new n‐type GaAs nanocone (GaAsNCs) array/monolayer graphene (MLG) Schottky junction is reported for NIR light detection. The NIR photodetector (NIRPD) shows obvious rectifying behavior with a turn‐on voltage of 0.6 V. Further device analysis reveals that the photovoltaic NIRPDs are highly sensitive to 850 nm light illumination, with a fast response speed and good spectral selectivity at zero bias voltage. It is also revealed that the NIRPD is capable of monitoring high‐switching frequency optical signals (~2000 Hz) with a high relative balance. Theoretical simulations based on finite difference time domain (FDTD) analysis finds that the high device performance is partially associated with the optical property, which can trap most incident photons in an efficient way. It is expected that such a self‐driven NIRPD will have potential application in future optoelectronic devices. 相似文献
993.
Ultraviolet‐Light‐Induced Reversible and Stable Carrier Modulation in MoS2 Field‐Effect Transistors
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Arun Kumar Singh Shaista Andleeb Jai Singh Hoang Tien Dung Yongho Seo Jonghwa Eom 《Advanced functional materials》2014,24(45):7125-7132
The tuning of charge carrier concentrations in semiconductor is necessary in order to approach high performance of the electronic and optoelectronic devices. It is demonstrated that the charge‐carrier density of single‐layer (SL), bilayer (BL), and few‐layer (FL) MoS2 nanosheets can be finely and reversibly tuned with N2 and O2 gas in the presence of deep‐ultraviolet (DUV) light. After exposure to N2 gas in the presence of DUV light, the threshold voltages of SL, BL, and FL MoS2 field‐effect transistors (FETs) shift towards negative gate voltages. The exposure to N2 gas in the presence of DUV light notably improves the drain‐to‐source current, carrier density, and charge‐carrier mobility for SL, BL, and FL MoS2 FETs. Subsequently, the same devices are exposed to O2 gas in the presence of DUV light for different periods and the electrical characteristics are completely recovered after a certain time. The doping by using the combination of N2 and O2 gas with DUV light provides a stable, effective, and facile approach for improving the performance of MoS2 electronic devices. 相似文献
994.
Photoinduced Anisotropic Supramolecular Assembly and Enhanced Charge Transport of Poly(3‐hexylthiophene) Thin Films
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Mincheol Chang Jiho Lee Nabil Kleinhenz Boyi Fu Elsa Reichmanis 《Advanced functional materials》2014,24(28):4457-4465
The self‐organization of organic polymer semiconductors into ordered supramolecular assemblies commensurate with efficient charge transport is achieved by tuning a range of process parameters (e.g., film deposition method (spin vs drop cast), solvent boiling point (low vs high boiling point), polymer‐dielectric interface treatment, and post‐deposition processing (solvent vapor or thermal annealing)). However, these strategies present limitations for large‐scale high‐throughput processing due to associated pre‐ and/or post semiconductor deposition steps. Here, photoinduced anisotropic supramolecular assembly of P3HT chains in solution is demonstrated. UV irradiation provides for enhanced intramolecular ordering of solubilized polymer chains, and thereby effects formation of anisotropic supramolecular polymer assemblies via favorable π–π stacking (intermolecular interaction). Molecular ordering is thus dramatically enhanced with concomitant, enhanced charge transport characteristics of corresponding films. Additional pre‐ and/or post treatments are avoided. 相似文献
995.
996.
Sílvia M. G. Rodrigues Margarida Facão Mário F. S. Ferreira 《Fiber and Integrated Optics》2015,34(1-2):76-89
AbstractKagome hollow-core photonic crystal fibers were found to be ideal for the occurrence of ultrafast non-linear optics. This article reports the optimal conditions for the generation of ultraviolet light using a gas filled kagome hollow-core-photonic crystal fiber. It is shown that by changing the pressure of the gas and the input pulse characteristics, the efficiency of conversion and quality of ultraviolet light can be improved, as well as tuning its central frequency. Results suggest that a highly coherent and tunable ultraviolet light source can be constructed, which can find numerous applications. 相似文献
997.
根据苯并(a)芘在特定光的照射下能够发出荧光的特性,采用紫外荧光法检测苯并(a)芘的浓度,构建了检测苯并(a)芘浓度的实验系统。为了精确地检测出苯并(a)芘的浓度,需要将实验中所得数据中所包含的噪声滤除掉,得到有效的荧光信号。将归一化最小均方自适应滤波(NLMS)的原理应用到光谱数据的噪声处理中,并将其与小波去噪的效果相比较,用Matlab仿真出去噪效果图,从不同的角度分析去噪效果。经过对比得出,用归一化最小自适应滤波能够继续保持信号的非平稳特性,达到更加理想的去噪效果,去噪性能更优,此种方法适用于荧光法检测物质浓度的信号处理中。 相似文献
998.
利用超短的紫外光源来增强阿秒脉冲的强度 总被引:1,自引:0,他引:1
本文理论提出了一种利用超短紫外光源来增强阿秒脉冲强度的方法 .计算结果表明,当适当的加入一束62 nm或者125 nm超短紫外光源到双色激光场时,不仅高次谐波的截止能量被延伸了,而且谐波的强度也比原双色场时有明显的增强.尤其是当采用125 nm光源时,谐波的强度被增强了2个数量级,并且形成了一个232 e V的超长平台区.最后通过叠加谐波次数从113次到170次可获得脉宽仅为43 as的孤立阿秒脉冲,其强度比原双色场情况下产生的阿秒脉冲增强了2个数量级. 相似文献
999.
AbstractA new approach for the simultaneous separation and indirect ultraviolet detection of four common fluorine-containing anions using 1-hexyl-3-methylimidazolium chloride as a mobile phase additive in reversed-phase chromatography was developed. The principle of separation and detection is that fluorine-containing anions and imidazolium cations form ion-pairs with ultraviolet absorption. Under the optimal determining conditions, the limits of detection for tetrafluoroborate, hexafluorophosphate, trifluoroacetate, and trifluoromethane sulfonate were 0.6, 0.6, 1.5, and 3.1?µmol/L, respectively. The approach has been successfully applied to the determination of these anions in ionic liquid samples, and the spiked recovery was between 98.5 and 102.6%. The detection limit, linearity, reproducibility, and accuracy of the approach are suitable for quantitative analysis. The method is simple and easy to popularize because of the use of a common C18 reversed-phase column and ultraviolet detector. 相似文献
1000.
Zhiyun Xu Wen Weng Yaobin Li Dr. Xitao Liu Tao Yang Maofan Li Prof. Xiaoying Huang Prof. Junhua Luo Prof. Zhihua Sun 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(48):21877-21881
Polarized-light detection in solar-blind ultraviolet region is indispensable for optoelectronic applications, whereas new 2D candidates targeted at solar-blind UV range remain extremely scarce. 2D hybrid perovskite ferroelectrics that combine polarization and semiconducting properties are of increasing interest. Here, using the 3D-to-2D dimensional reduction of CH3NH3PbCl3, we designed a multilayered hybrid perovskite ferroelectric, (CH3CH2NH3)2(CH3NH3)2Pb3Cl10, which shows spontaneous polarization and a high Curie temperature (390 K) comparable with that of BaTiO3 (393 K). The wide band gap (ca. 3.35 eV) and anisotropic absorbance stemming from its intrinsic 2D motif, greatly favor its polarization-sensitive activity in UV region. The device displays excellent polarization-sensitive behavior under 266 nm, along with a large dichroic ratio (ca. 1.38) and high on/off current ratio (ca. 2.3×103). 相似文献