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Investigation of edge states variation in valley photonic crystals by modulating the refractive index of domain walls

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Optoelectronics Letters 2025年第3期21卷 160-166页

作者： ZHANG Run ZHONG Xingli LIN Zhongxi QIU Weibin SU Hui key laboratory of Optoelectronic Materials Chemistry and Physics Collaborative Innovation Center for Optoelectronic Semiconductors and Efficient Devices Fujian Institute of Research on the Structure of Matter Chinese Academy of Science University of Chinese Academy of Sciences Chinese Academy of Sciences College of information Science and Engineering Huaqiao University Fujian Science & technology Innovation laboratory for Optoelectronic information of China

Realizing the valley Hall effect by breaking the spatial inversion symmetry of photonic systems has become a cutting-edge field of micro-nano-optics, since the valley degree of freedom was introduced into photonic system. Various novel devices based on the domain walls of the valley photonic crystals have also been demonstrated. In this article,we investigate the variation of edge states by the modulation of refractive index within the domain walls, and the geometric difference between the dielectric columns of the sublattices. Straight photonic crystal waveguides with three types of domain walls (bearded, zigzag, armchair) are constructed. Simulation results show that the creation of a double-edge state in the band diagram results in two windows of stable transmission in tunable bands. Our findings might have significant implications in the field of novel optical devices.

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How to characterize capacitance of organic optoelectronic devices accurately

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Chinese Physics B 2018年第6期27卷 382-386页

作者： Hao-Miao Yu Yun He key laboratory of luminescence and optical information Ministry of Education School of Science Beijing Jiaotong University Beijing 100044 China National key laboratory of Science and technology on Space Microwave China Academy of Space Technology （Xi＇ an） Xi＇ an 710100 China

The selection of circuit model（i.e., parallel or series model） is critical when using a capacitance–frequency and capacitance–voltage technique to probe properties of organic materials and physical processes of organic optoelectronic devices. In the present work, capacitances of ITO/Alq3/Al and ITO/CuPc/Al are characterized by series and parallel model,respectively. It is found that the large series resistance comes from the ITO electrode and results in the inapplicability of the parallel model to measuring the capacitances of organic devices at high frequencies. An equivalent circuit model with consideration of the parasitical inductance of cables is constructed to derive the capacitance, and actual capacitance–frequency spectra of Alq3 and CuPc devices are obtained. Further investigation of temperature-dependent capacitance–frequency and capacitance–voltage characteristics indicates that CuPc and Al form the Schottky contact, the density and ionization energy of impurities in CuPc are obtained. Moreover, more practical guidelines for accurate capacitance measurement are introduced instead of the impedance magnitude, which will be very helpful for the organic community to investigate capacitance-related characteristics when dealing with various organic optoelectronic devices.

关键词： organic semiconductor capacitance characterization Schottky contact ionization energy

Polymer Light-Emitting Diode Using Conductive Polymer as the Anode Layer

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Chinese Physics Letters 2010年第9期27卷 217-220页

作者：梁春军邹辉何志群张春秀李丹王永生 key laboratory of luminescence and optical information (Ministry of Education) Beijing Jiaotong University Beijing 100044 Beijing Institute of Graphic Communication Beijing 102600

The analysis based on series equivalent circuit indicates that the resistance of electrode layers is the major factor limiting the current density of polymer light-emitting diodes （PLEDs） at higher voltages. The conductivity of 790 S/cm for the PEDOT：PSS film is achieved by secondary doping. At a thickness of 240 nm, the sheet resistance of the polymer layer is 51 Ω/sq, which is comparable to that of lTO films. The current density and luminance of the PLEDs with the polymer anode layer is higher than the ITO anode device, suggesting that it is feasible to replace ITO anode with a highly conductive polymer in PLEDs.

关键词： Polymers Polymerization Layering Films Packaging materials Density

Coherent and Incoherent Interactions between Discrete-Soliton Trains in Two-Dimensional Light-Induced Photonic Lattices

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Chinese Physics Letters 2007年第12期24卷 3435-3438页

作者：肖发俊张鹏刘圣赵建林 Institute of optical information Science and technology Sha~nxi Key Laboratory of Optical Information Technology School of Science Northwestern Polytechnical University Xi'an 710072

The coherent and incoherent interactions between discrete-soliton trains are numerically investigated in lightinduced two-dimensional photonic lattices. The solutions of discrete-soliton trains for diamond and square lattices are obtained by Petviashvili iteration method. It is found that for both the kinds of lattices, two in-phase （out- of-phase） discrete-soliton trains attract （repel） each other, and the intermediates are always accompanied with energy transfer. While the interaction forces between two incoherent discrete-soliton trains are always attractive.

关键词： thermoelectric half-Heusler compounds thermal conductivity

Photovoltaic properties of MEH-PPV/TiO_2 nanocomposites

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Chinese Science Bulletin 2008年第18期53卷 2743-2747页

作者： LI Yan HOU YanBing JIN Hui SHI QuanMin WANG Yan FENG ZhiHui key laboratory of luminescence and optical information Ministry of Education of China Institute of Optoelectronic Technology Beijing Jiaotong University Beijing 100044 China

Photovoltaic properties of photodiodes based on nano-TiO_2 and poly[2-methoxy,5-(2′-ethlhexyloxy)- p-phenylenevinylene] (MEH-PPV) composites are investigated. By comparing composite devices with the same weight of TiO_2 (nanoparticles and nanotubes):MEH-PPV, it was found that the device with TiO_2 nanotubes exhibited better performance. By further optimizing the weight radio of TiO_2 nano- tubes:MEH-PPV, we gained the device with a short circuit current density of 9.27 μA/cm2 with a light intensity of 16.7 mW/cm2 at the 500 nm wavelength, the highest open-circuit voltage of 1.1 V, and a photosensitivity of 332 at reverse bias of -0.6 V. The photosensitivity is improved by a factor of 33 compared with the undoped MEH-PPV device.

关键词：太阳能电池氧化硅纳米管 MEH-PPV 纳米复合材料

Efficiency enhancement of P3HT:PCBM polymer solar cells using oligomers DH4T as the third component

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Science China Chemistry 2015年第7期58卷 1169-1175页

作者： Ping Fu Dong Yang Fujun Zhang Wei Yu Jian Zhang Can Li State key laboratory of Catalysis Dalian Institute of Chemical Physics Chinese Academy of Sciences and Dalian National Laboratory for Clean Energy key laboratory of luminescence and optical information Ministry of Education University of Chinese Academy of Sciences

We assembled a ternary blend bulk heterojunction polymer solar cell(PSCs) containing P3HT(donor) and PC61BM(acceptor) incorporated with a small molecule oligomer, dihexyl-quaterthiophene(DH4T) as a third component. By optimizing the contents of DH4 T, we increased the power conversion efficiency of ternary P3HT:DH4T:PC61BM PSCs to 4.17% from 3.44% of binary P3HT:PC61BM PSCs under AM 1.5 G of 100 m W/cm2 intensity. The major improvement is from the increase of the short circuit current and fill factor that is due to the increased light absorption at short wavelength, the balanced charge carrier transportation and the enhanced hole evacuation by a DH4T-enriched layer at the anode interface. In this work, we demonstrated that the efficiency of the PSCs can be enhanced by using low-bandgap conjugated polymer and its oligomer as donors and fullerene derivatives as acceptors.

关键词： ternary polymer solar cells P3HT:PC61BM oligomer mobility balanced charge carrier transportation

Polarization-encoded neural networks with simplified grating patch

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Science China Technological Sciences 2025年

作者： Chengyan ZHONG Xiang WANG Lingfei LI Yuanchi CUI Lei XIAO Dawei SONG Junxiong GUO Wen HUANG Yufeng GUO Yu LIU College of Integrated Circuit Science and Engineering Nanjing University of Posts and Telecommunications National and Local Joint Engineering laboratory of RF Integration and Micro-Assembly technology College of Integrated Circuits Hangzhou Global Scientific and Technological Innovation Centre Zhejiang University Nanjing Mumusili technology Co. LTD School of Integrated Circuits Tsinghua University Institute of Advanced Study School of Electronic Information and Electrical Engineering Chengdu University State key laboratory of Electronic Thin Films and Integrated Devices School of Integrated Circuit Science and EngineeringUniversity of Electronic Science and Technology of China

optical neural networks (ONNs) offer a promising solution for high-performance, energy-efficient artificial intelligence hardware by leveraging the parallelism and speed of light. However, the large-scale implementation of ONNs remains challenging due to the bulky footprint and complex control of optical synapses. In this work, we propose and simulate a plasmonic polarized synaptic architecture that overcomes the diffraction limit and enables ultra-compact ONNs. By tuning the polarization state of incident light, the optical transmittance through each plasmonic unit can be dynamically adjusted to represent a synaptic weight. Our plasmonic structures, with features as small as 40 nm, operate well below this limit in the visible spectrum (400–750 nm). Compared with diffraction and interference-based circuit designs, our proposed method achieves a substantial reduction in synaptic density by factors of 150000-fold and 1500-fold, respectively. Furthermore, we successfully demonstrate a proof-of-concept plasmonic ONN applied to the Canadian Institute for Advanced Research—10classes (CIFAR-10) dataset using a Visual Geometry Group network with 16 layers (VGG16) model. After training for 80epochs, the network achieves an accuracy of 93%. The polarization-tunable plasmonics paves the way towards scalable ONNs for next-generation artificial intelligence (AI) accelerators and smart sensors.

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From kesterite 2D nanosheets to wurtzite 1D nanorods:controllable synthesis of Cu-Zn-Sn-S and their application in electrocatalytic hydrogen evolution

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Journal of Semiconductors 2023年第12期44卷 104-110页

作者： Yu Li Shuaibing Wang Jie Chen Ouyang Lin Zhe Yin Chunhe Yang Aiwei Tang key laboratory of luminescence and optical information Ministry of EducationSchool of Physical Science and EngineeringBeijing Jiaotong UniversityBeijing 100044China

As typical quarternary copper-based chalcogenides,Cu–Zn–Sn–S nanocrystals(CZTS NCs)have emerged as a newfashioned electrocatalyst in hydrogen evolution reactions(HERs).Oleylamine(OM),a reducing surfactant and solvent,plays a significant role in the assisting synthesis of CZTS NCs due to the ligand ***,we adopted a facile one-pot colloidal method for achieving the structure evolution of CZTS NCs from 2D nanosheets to 1D nanorods assisted through the continuous addition of *** the process,the mechanism of OM-induced morphology evolution was further *** merely adding pure 1-dodecanethiol(DDT)as the solvent,the CZTS nanosheets were *** OM was gradually added to the reaction,the CZTS NCs began to grow along the sides of the nanosheets and gradually shrink at the top,followed by the formation of stable *** acidic electrolytic conditions,the CZTS NCs with 1.0 OM addition display the optimal HER activity with a low overpotential of 561 m V at 10 m A/cm^(2) and a small Tafel slope of 157.6 m V/dec compared with other CZTS *** enhancement of HER activity could be attributed to the contribution of the synergistic effect of the diverse crystal facets to the reaction.

关键词： 2D nanosheets 1D nanorods structure evolution Cu-Zn-Sn-S electrocatalytic hydrogen evolution

Dynamically measuring the holo-information of light fields in three-dimensional space using a periodic polarization-structured light

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Science China(Physics,Mechanics & Astronomy) 2021年第6期64卷 58-65页

作者： ShuXia Qi Sheng Liu Lei Han BingYan Wei Peng Li JinZhan Zhong XuYue Guo JianLin Zhao key laboratory of Light-field Manipulation and information Acquisition Ministry of Industry and Information Technologyand Shaanxi Key Laboratory of Optical Information TechnologySchool of Physical Science and TechnologyNorthwestern Polytechnic UniversityXi'an 710129China

Spatially structured light field has attracted great attention due to its novel properties and application potential in numerous *** them,the most striking one is the polarization-structured light,known as the vector ***,using a periodic polarization-structured light,we propose a method to dynamically measure the holo-information of light fields,including the amplitude,phase,and polarization distributions,in three-dimensional(3D)*** measurement system is composed of a Mach-Zender interferometer involving a liquid crystal polarized grating in the reference arm,which is simple,stable,and easy to *** the single-shot measurement,this method supports observing the dynamic variation of object light *** accuracy,3D polarimetry,and dynamic observation of this method are validated by measuring a calibrated quarter-wave plate,a vector vortex beam,a Poincarébeam,and a stressed polymethyl methacrylate sample.

关键词： polarization structured light measurement holography