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An ultra-wideband circularly polarized microstrip patch antenna loaded with split-ring resonator

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Optoelectronics Letters 2025年

作者： WANG Shike XIA Dan Lü Lianrong QIN Juan WANG Meng REN Haiping school of integrated circuit science and engineering， tianjin university of technology

In this paper， the effect of a single-opening split-ring resonator （SRR） structure on the performance of ultra-wideband （UWB） microstrip patch antenna （MPA） is studied. Here a UWB MPA based on partial grounding is proposed， and the SRR structure is utilized to optimize other characteristics of the low-profile microstrip antenna while ensuring the bandwidth and gain remain unchanged. The proposed metamaterial structure， consisting of a 2 × 2 array of SRR， is loaded on the reverse side of the substrate. The volume of the proposed antenna is 61.6×67.6×1.5mm3. According to simulation and experimental results， the proposed microstrip antenna loaded with 2×2 SRRs performs better than that without SRR structure. It produces an operating band of 1.62 GHz-8 GHz while achieving circular polarization characteristics with an axial ratio （AR） bandwidth of 3.92 GHz-4.57 GHz. In addition， the performance of the proposed antenna is superior to relevant works of literature The antenna can be widely utilized in wireless communication systems.

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Improved model for defect detection in photovoltaic cells based on Yolov5

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Optoelectronics Letters 2025年

作者： BAI Xinfeng XUE Yuming DAI Hongli WANG Luoxin BAI Xin HU Xiaofeng Institute of New Energy Intelligence Equipment， school of integrated circuit science and engineering， tianjin university of technology

In order to meet the requirements of recognition speed and accuracy for complex photovoltaic (PV) cell defect detection tasks， this paper proposed an improvement strategy based on the Yolov5 network model. First， the model's ability to localize defects was enhanced by adding shallow feature inputs to strengthen the model's fusion of shallow feature information; second， the Squeeze-and-excitation (SE) attention mechanism was introduced to expand the receptive field and strengthen the dependency between feature channels; finally， a smoothing downsampling module was constructed to replace the convolutional sampling， which reduced the loss of information while retaining the important features. The experimental results show that the Yolov5 model based on this improved strategy achieved an average accuracy of 92.06% in the multiclassification defect detection task， and the average recognition speed reached 25.31 frames per second (FPS)， which took into account the requirements of performance and real-time performance， and can satisfy the needs of PV cell defect detection in industrial scenarios.

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Influence of band gap and different defects on the performance of Cu（In， Ga）Se2 solar cells

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Optoelectronics Letters 2025年

作者： LU Yahan XUE Yuming DAI Hongli WANG Luoxin LI Weiwei JI Licui Institute of New Energy Intelligence Equipment， school of integrated circuit science and engineering， tianjin university of technology

The SCAPS-1D simulator， a one-dimensional solar cell capacitance simulator is utilized for simulating CIGS solar cells. It has been observed that the performance of solar cells can be enhanced by uniformly adjusting the band gap value of the CIGS absorption layer. Upon doing so， the solar cell's conversion efficiency reaches 22.13% when the band gap of the CIGS absorption layer is 1.3eV. Subsequently， the influence of defect type and density on photoelectric properties is analyzed by using the improved absorption band gap. The findings indicate that to heighten the photovoltaic efficiency， it is imperative to minimize the defect concentration in the absorption layer， as high-density defects significantly impact the efficiency， and can even render the conversion efficiency to zero. This study underscores the pivotal influence of band gap adjustments and defect charge types on the photoelectric properties of thin film solar cells.

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Enhancing the performance of the absorber of Cu2ZnSn（S， Se）4 photovoltaic materials by doping Cd2+

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Optoelectronics Letters 2025年

作者： YANG Shuqi XUE Yuming DAI Hongli WANG Luoxin ZHANG Haiwei BAI Xin Institute of New Energy Intelligence Equipment， school of integrated circuit science and engineering， tianjin university of technology

Cationic doping is considered to be an effective way to improve the efficiency of Cu2ZnSn（S，Se）4（CZTSSe） photovoltaic materials. To improve the quality of the absorption layer of the crystal film， CZTSSe film was doped with some Cd to change the ratio of Cd and Zn in the precursor solution. XRD， Raman， SEM， UV-Vis spectroscopy， and other results showed that Cd successfully replaced Zn in the crystal lattice during post-selenization. The formation of harmful Zn-related defects was reduced， the grain size and crystallinity of the films were significantly increased， and the photoelectric properties of the films such as crystal quality and structural morphology were improved. As the Cd/（Cd+Zn） ratio increased from 0 to 0.35， the band gap of CZCTSSe decreased to 1.02eV. When Cd/（Cd+Zn）=0.25， the crystallinity and grain size reached the best value， and the film surface was smooth and dense， which inhibited the formation of the second phase on the surface of *** theoretical basis and experimental results showed that proper Cd doping can promote the growth of grain， so that compact CZCTSSe films with larger grain sizes and fewer holes could be prepared.

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Effect of ammonia concentration of complexing agent on CdxZn1-xS buffer layer by chemical bath deposition and performance of CIGS cell

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Optoelectronics Letters 2025年

作者： LU Yahan XUE Yuming DAI Hongli WANG Luoxin ZHOU Liwei TAN Zhiyuan Institute of New Energy Intelligence Equipment， school of integrated circuit science and engineering， tianjin university of technology

In this paper， CdxZn1-xS thin films were deposited on glass substrates by chemical bath deposition （CBD），and the effects of different concentrations of ammonia water on the morphology， structure and optical properties of the films were studied. CdxZn1-xS thin films have hexagonal crystal structure， the transmittance is above 75% in the visible range， and the optical band gap is between 2.6 eV and 2.9 eV. The influence of the experimental group of deposited thin films on the performance parameters of the CIGS battery was studied by simulation with SCAPS-1D software and the cell efficiency reached 22.42%. It is introduced that the buffer layer prepared in this experiment is feasible in CIGS solar cells.

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The effects of selenization conditions on the microstructure and optoelectronic properties of CZTSSe absorber layers prepared by the sol-gel method

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Optoelectronics Letters 2025年

作者： BAI Xin XUE Yuming DAI Hongli WANG Luoxin BAI Xinfeng HU Xiaofeng Institute of New Energy Intelligence Equipment， school of integrated circuit science and engineering， tianjin university of technology

Cu2ZnSnSSe4（CZTSSe） thin film solar cells， with adjustable bandgap and rich elemental content， hold promise in next-gen photovoltaics. Crystalline quality is pivotal for efficient light absorption and carrier transport. During the post-selenization process， understanding crystal growth mechanisms， and improving layer quality are essential. We explored the effects of ramp rate and annealing temperature on CZTSSe films， using XRD， Raman， SEM， and UV-Vis. The optimal performance occurred at 25.25 ℃/min ramp rate and 530℃ annealing. This led to smoother surfaces， higher density， and larger grains. This condition produced a single-layer structure with large grains， no secondary phases， and a 1.14 eV bandgap， making it promising for photovoltaic applications. The study has highlighted the effect of selenization conditions on the characteristics of the CZTSSe absorber layer and has provided valuable information for developing CZTSSe thin film solar cells.

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High-quality environmentally friendly photovoltaic CZTSSe thin films prepared by Mg doping

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Optoelectronics Letters 2025年

作者： Zhang Zihe Xue Yuming Dai Hongli Wang Luoxin Bai Xin Hu Xiaofeng Institute of New Energy Intelligence Equipment， school of integrated circuit science and engineering， tianjin university of technology

CZTSSe thin films were prepared using the sol-gel method， and the crystal morphology of the CZTSSe films were improved by Mg doping. The prepared films were characterized using techniques such as XRD， Raman spectroscopy， SEM， and UV-Vis spectroscopy. The results showed that Mg replaced Zn in the CZTSSe lattice， forming the CMZTSSe phase. As the Mg doping concentration increased， the grain size initially increased and then decreased. After Mg doping， no additional impurities are *** the Mg doping concentration was 0.1， the film exhibited the optimal crystal morphology， narrowest peak width， largest grain size， the best light absorption properties smoothest and most compact surface， which is favorable for use as an absorber layer in solar cells.

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High-temperature-tolerant flexible supercapacitors: Gel polymer electrolytes and electrode materials

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Journal of Energy Chemistry 2025年第1期100卷 426-457页

作者： Chong Peng Xinyi Huang Mingwei Zhao Shuling Liao Quanhong Yang Nianjun Yang Siyu Yu school of Chemistry & Chemical engineering Southwest University Nanoyang Group Tianjin Key Laboratory of Advanced Carbon and Electrochemical Energy Storage School of Chemical Engineering and Technology and Collaborative Innovation Center of Chemical Science and Engineering (Tianjin) Tianjin University Department of Chemistry & IMO-IMOMEC Hasselt University

The development of flexible supercapacitors(FSCs) capable of operating at high temperatures is crucial for expanding the application areas and operating conditions of supercapacitors. Gel polymer electrolytes and electrode materials stand as two key components that significantly impact the efficacy of hightemperature-tolerant FSCs(HT-FSCs). They should not only exhibit high electrochemical performance and excellent flexibility, but also withstand intense thermal stress. Considerable efforts have been devoted to enhancing their thermal stability while maintaining high electrochemical and mechanical performance. In this review, the fundamentals of HT-FSCs are outlined. A comprehensive overview of state-of-the-art progress and achievements in HT-FSCs, with a focus on thermally stable gel polymer electrolytes and electrode materials is provided. Finally, challenges and future perspectives regarding HT-FSCs are discussed, alongside strategies for elevating operational temperatures and *** review offers both theoretical foundations and practical guidelines for designing and manufacturing HT-FSCs, further promoting their widespread adoption across diverse fields.

关键词： Polymer membrane electrodes

A denoising algorithm based on the improved EWT in distributed fiber optic temperature measurement system

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Optoelectronics Letters 2025年

作者： Xu Xiaoyi Hu Kai Wei Xiaoying Zhang Kailiang tianjin university of technology， school of integrated circuit science and engineering Aerospace Optoelectronic technology Development Co.， Ltd.

In order to enhance the temperature measurement accuracy of Raman distributed fiber optic temperature measurement system， in this paper， we propose a distributed fiber optic temperature measurement signal denoising algorithm based on the empirical wavelet transform with improved thresholding. This algorithm is used to decompose the noisy signal into multiple intrinsic modal threshold functions， which are further reconstructed by correlation filtering and threshold processing each of the IMFs using an improved function. The correlation filtering mechanism in this algorithm effectively reduces the regular noise and the amount of computation to improve the response speed. The improved threshold function can significantly reduce the spiky noise and smoothen the signal. The field temperature data is collected in the experiment， and the algorithm is implemented in the FPGA platform. In measured results， the system's temperature measurement accuracy is ±0.18℃ over 2.5 km of sensing fiber， with average response time is 0.6 seconds.

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