Search Results (443)

The integration of complementary metal–oxide–semiconductor (CMOS) and micro-electromechanical systems (MEMSs) technologies for miniaturized biosensor fabrication enables unprecedented spatiotemporal resolution in monitoring the bioelectrical activity of the nervous system. Wafer-level CMOS technology incurs high costs, but multi-project wafer (MPW) runs mitigate this by allowing multiple users to share a single wafer. Still, monolithic CMOS biosensors require specialized surface materials or device geometries incompatible with standard CMOS processes. Performing MEMS post-processing on the few square millimeters available in MPW dies remains a significant challenge. In this paper, we present a MEMS post-processing workflow tailored for CMOS dies that supports both surface material modification and layout shaping for intracortical biosensing applications. To address lithographic limitations on small substrates, we optimized spray-coating photolithography methods that suppress edge effects and enable reliable patterning and lift-off of diverse materials. We fabricated a needle-like, 512-channel simultaneous neural recording active pixel sensor (SiNAPS) technology based neural probe designed for integration with optical fibers for optogenetic studies. To mitigate photoelectric effects induced by light stimulation, we incorporated a photoelectric shield through simple modifications to the photolithography mask. Optical bench testing demonstrated >96% light-shielding effectiveness at 3 mW of light power applied directly to the probe electrodes. In vivo experiments confirmed the probe’s capability for high-resolution electrophysiological measurements. Full article

To address the high-temperature and high-cost challenges of the conventional dry oxidation process in boron diffusion for n-type tunnel oxide passivated contact solar cells, this study proposes a dry–wet–dry mixed oxidation drive-in process for fabricating p-type emitters in TOPCon solar cells. Through systematic investigation of oxidation temperature, O₂/H₂O flow ratio, and oxidation time effects on emitter performance, it is found that mixed oxidation at 1000 °C achieves comparable sheet resistance and doping profiles to dry oxidation at 1050 °C. For our newly developed mixed oxidation process, in which the oxidation temperature is 1000 °C, oxidation time is 80 min with O₂/H₂O flow ratio of 20:1, the same photoelectric conversion efficiency has been achieved. Comparing the data, the mixed oxidation process forms a dry/wet/dry three-layer SiO₂ structure, reducing the oxidation temperature by 50 °C while achieving an average efficiency of 26.02%, comparable to high-temperature dry oxidation. This process not only reduces the thermal budget of quartz tubes and extends equipment service life but also provides a feasible solution for the low-temperature manufacturing of high-efficiency TOPCon solar cells, showing significant industrial application prospects. Full article

A double-cavity vertical-cavity surface-emitting laser (VCSEL) can effectively suppress high-order transverse modes and achieve a high side-mode suppression ratio (SMSR). However, the double cavity also results in increased fundamental mode loss, reducing output power. In this study, both p-type and n-type oxide layers were simultaneously incorporated into a double-cavity VCSEL and the structure was numerically simulated using Pics3D (2024) software. The simulation results indicate that this approach can significantly enhance the output power, strengthen the single-transverse-mode characteristic, and thus improve the side-mode suppression ratio (SMSR). Generally, as the number of oxide layers increases, their ability to confine the optical field also enhances, trapping more high-order transverse modes within the oxide aperture, leading to a decrease in SMSR. However, in this study, the introduction of an n-type layer resulted in an abnormal increase in the SMSR, because the n-type oxide layer is situated between the active region and the second cavity. When the optical field oscillates between these two regions, some high-order transverse modes are blocked by the n-type oxide holes and cannot participate in mode competition, thereby increasing the SMSR. Full article

The widespread application of Rhodamine B (RhB) poses a serious threat to the aquatic environment. ZnFe₂O₄, as a catalyst material, can effectively activate persulfate (PMS) and respond to visible light, thus effectively degrading RhB with the joint assistance of sunlight and PMS. This study recovered Fe₂O₃ from high-iron coal gangue through an activating–acid leaching–extracting–back-extracting process and synthesized ZnFe₂O₄ catalysts (CG-ZFO) using coal gangue back-extraction liquid as the Fe source by a hydrothermal method and cetyltrimethylammonium bromide (CTAB)-assisted hydrothermal method. The characterization results of X-ray diffraction (XRD), scanning electron microscopy (SEM), and diffuse reflectance spectroscopy (DRS) showed that the CG-ZFO has a pure crystal phase, and the addition of CTAB can effectively improve the photoelectric performance of the catalyst. The synthesized CG-ZFO can produce a significant synergistic effect with simulated sunlight (SS) and PMS, and the constructed SS/CG-ZFO/PMS system had a good degradation effect on RhB. Based on the conclusions of free radical-quenching experiments, electron paramagnetic resonance (EPR) spectroscopy, and X-ray photoelectron spectroscopy (XPS), the main active species in the SS/CG-ZFO/PMS system was identified as ₁O², and the degradation mechanism of RhB was elucidated. CG-ZFO prepared from coal gangue holds promising potential for application in the remediation of organic dye wastewater, and this study also provides a new approach for the resource regeneration of high-iron coal gangue. Full article

ZnO thin-film ultraviolet photodetectors are widely used in the military, space, environmental protection, medicine, and other fields. Accurate printing of ZnO photoelectric-sensitive films plays a key role in the detection results. Therefore, obtaining printing technology with a simple process and high precision has become a challenge for ZnO photoelectrically sensitive films. By adjusting the distance between the nozzle and the collecting plate, the jet is atomized in a straight line and deposited directly on the collecting plate, which effectively improves the stability and controllability of the jet spraying and deposition processes. ZnO thin films with a uniform distribution of nanoparticles, significantly improved density, and controllable deposition area linewidth were successfully prepared. The effects of different ZnO film structures on the performance of ultraviolet photodetectors were tested. When the ultraviolet light intensity is 500, 1000, and 2500 mW/cm², the $I_{light}$ of the photodetector is 4.62, 9.38, 14.67 mA, The on/off ratio ($I_{light}$/$I_{dark}$) is 20.7, 42.1, 65.8, implying satisfactory photoelectric performance as well as high stability and repeatability, providing an effective technical means for the precise printing application of micro-nano functional devices. Full article

Light-controlled ion drag pumps have attracted considerable interest in soft robotics, biomedical engineering, and microelectromechanical systems (MEMS) due to their non-contact energy supply and high spatiotemporal controllability of light. However, experimental studies on their pumping performance and influencing factors remain limited. This study integrates the photoelectric effect with field emission phenomena to design and fabricate a light-controlled ion drag pump using lanthanum-modified lead zirconate titanate (PLZT) ceramic. The light-controlled pump enables non-contact energy transfer and fluid transport via high-energy laser irradiation. A series of experiments systematically investigate its pumping performance and key influencing factors. Results indicate that optimizing electrode structure and fluid channel design, along with increased light intensity, significantly enhances pumping performance. This work provides fundamental design guidelines for the application of light-controlled ion drag pumps in microfluidics, flexible robotics, and microdevice thermal management. Full article

The implementation of photoelectric conversion in photoelectric integrated systems requires the design of photodetectors (PDs) with quick response times and low power consumption. In this work, the self-powered photodetector was prepared by antimony selenide (Sb₂Se₃) microwires (MW)/Se microtube (MT) heterojunction by coating Ag nanowires (NW). The incorporation of Ag-NW involves dual enhancement mechanisms. First, the surface plasmon resonance (SPR) effect amplifies the light absorption across UV–vis–NIR spectra, and the conductive networks facilitate the rapid carrier transport. Second, the type-II band alignment between Sb₂Se₃ and Se synergistically separates photogenerated carriers, while the Ag-NW further suppress the recombination through built-in electric field modulation. The optimized device achieves remarkable responsivity of 122 mA W⁻¹ at 368 nm under zero bias, with a response/recovery time of 8/10 ms, outperforming most reported Sb₂Se₃-based detectors. The heterostructure provides an effective strategy for developing self-powered photodetectors with broadband spectral adaptability. The switching ratio, responsivity, and detectivity of the Sb₂Se₃-MW/Se-MT/Ag-NW device increased by 260%, 810%, and 849% at 368 nm over the Sb₂Se₃-MW/Se-MT device, respectively. These results show that the addition of Ag-NW effectively improves the photoelectric performance of the Sb₂Se₃-MW/Se-MT heterojunction, providing new possibilities for the application of self-powered optoelectronic devices. Full article

Background/Objectives: Frailty is an age-related clinical syndrome characterized by diminished physiological reserves and increased vulnerability to adverse outcomes. Growing evidence suggests that frailty involves shared brain networks that regulate both gait and cognitive functions. This study aimed to examine the relationship between frailty status, spatiotemporal gait parameters, and cognitive functions in community-dwelling older adults. Methods: A cross-sectional study was conducted with 99 adults aged ≥70 years, classified as non-frail, prefrail, or frail according to the Fried phenotype. Gait parameters were measured under usual and fast walking conditions using the OptoGait^® photoelectric system. Cognitive status was assessed with the Montreal Cognitive Assessment (MoCA) and a comprehensive neuropsychological battery. Multivariate logistic regression analyses were performed to identify factors associated with transitions between frailty stages. Results: The prevalence of frailty was 9.1%, with 51.5% prefrail and 39.4% non-frail. The transition from non-frail to prefrail was associated with shorter stride length at fast pace (OR = 0.92, 95% CI: 0.88–0.96), mild cognitive impairment (OR = 3.71, 95% CI: 1.08–12.69), depressive symptoms (OR = 1.82, 95% CI: 1.26–2.62), and female sex (OR = 4.94, 95% CI: 1.20–16.77). The transition from prefrail to frail was linked to increased stride time variability at fast pace (OR = 2.94, 95% CI: 1.34–6.44) and poorer working memory (OR = 0.40, 95% CI: 0.16–0.97). Conclusions: Shorter stride length, mild cognitive impairment, and depressive symptoms emerged as key markers of the transition from non-frailty to prefrailty, whereas increased stride time variability and poorer working memory distinguished prefrail from frail individuals. These findings highlight gait- and executive-function-related markers as sensitive early indicators of vulnerability. Incorporating quantitative gait assessment and brief cognitive screening into routine geriatric evaluations may substantially enhance early detection and support targeted preventive strategies for healthy aging. Full article

Solar photovoltaic (PV) power generation has become an important source of global renewable energy. The photoelectric conversion efficiency of crystalline silicon PV modules decreases as their surface temperature rises, while excessively high operating temperatures can also affect their service life. Therefore, reducing the temperature of photovoltaic modules is one of the effective methods of enhancing their photoelectric conversion efficiency. Passive thermal management methods, such as the use of phase change materials (PCM) and heat pipes (HP), can be used to control the temperature of PV modules, but they manifest the problems of poor thermal conductivity and low heat transfer efficiency at low heat flux density, respectively. On the other hand, previous experimental studies have mostly focused on small-scale non-standard PV cell modules, without considering encapsulation and installation issues in practical applications. Meanwhile, passive cooling technology exhibits strong regional characteristics, with significant variations in temperature control and energy efficiency improvements under different climatic conditions. To address these issues, this paper proposes a novel PV module temperature control unit that couples PCM and HP. Standard commercial PV cell modules are used as experimental subjects, and tests are conducted in four different regions of China to study the adaptability and effectiveness of the coupled PCM and HP control method. The experimental results show that the power generation pattern of PV modules is consistent with the variation in solar radiation intensity. When the operating temperature of the PV module is below 40 °C, the high thermal conductivity of the heat pipe plays a dominant role in dissipating heat. When the operating temperature of PV rises above 40 °C, the phase change material begins to play a role in heat storage and temperature control. Compared to using PCM alone for temperature control, the coupled method further enhances the cooling effect, preventing a sharp temperature increase after the PCM has completely melted, and increases the power generation of PV by 4–5%. The temperature control effect of the PV module is influenced by local ambient temperature and wind speed. The coupled temperature control method exerts a relatively low improvement effect under high-temperature and low-radiation environmental conditions, but it performs better when used under low-temperature and high-radiation environmental conditions. Full article

With the rapid development of renewable energy, surface defect detection of photovoltaic panels has become an important link in improving photoelectric conversion efficiency and ensuring safety. However, there are various types of surface defects on photovoltaic panels with complex backgrounds, and traditional detection methods face challenges such as low efficiency and insufficient accuracy. This article proposes a lightweight improved model AE-YOLO (YOLOv11+Adown +ECA) based on YOLOv11, which improves detection performance and efficiency by introducing a lightweight dynamic down-sampling module (Adown) and an Efficient Channel Attention (ECA). The Adown module reduces the complexity of computational and parameters through steps such as average pooling preprocessing, channel dimension segmentation, branch feature processing, and feature fusion. The ECA mechanism enhances the model’s response to defect sensitive feature channels and improves its ability to discriminate low contrast small defects through adaptive average pooling, one-dimensional convolution, and sigmoid activation. The experimental results indicate that the AE-YOLO model performs well on the PVEL-AD dataset. mAP@0.5 reached 90.3%, the parameter count decreased by 18.7%, the computational load decreased by 19%, and the inference speed reached 259.56 FPS. The ablation experiment further validated the complementarity between Adown and ECA modules, providing an innovative solution for real-time and accurate defect detection of photovoltaic panels in industrial scenarios. Full article

An ultrathin Al layer was introduced into AZO/Cu/AZO films to further enhance the optoelectronic performance. The AZO/Al/Cu/AZO films were deposited on glass substrates by DC and RF magnetron sputtering; the microstructure and optoelectronic properties were analyzed by XRD, SEM, AFM, TEM, visible spectrophotometer, and Hall effect measurement system. The results indicated that the Al layer played a crucial role in modulating the crystallization behavior and optoelectronic properties of the films, exhibiting a distinct thickness-threshold effect. At an Al layer thickness of 1 nm, the film exhibited optimal optoelectronic performance, achieving a high F_OM of 0.71 Ω⁻¹, a high transmittance of 85%, and a low resistivity of 5.7 × 10⁻⁵ Ω·cm. However, when the Al layer thickness exceeded 1 nm, the crystallinity of the films deteriorated significantly, the grain boundary scattering and light absorption effect enhanced, leading to the deterioration of photoelectric properties. The introduction of the Al layer significantly improved the stability of the films, and the AZO/Al(2 nm)/Cu/AZO film exhibited the best temporal stability after being exposed to air for 20 months. Full article

In this study, a novel photocatalytic nanomaterial BiTmFeSbO₇ was successfully synthesized for the first time by using the solvothermal method. On account of the effective Z-scheme mechanism, the BiTmFeSbO₇/BiTmO₃ heterojunction photocatalyst (BTBTHP) could effectively separate the photoinduced electrons and the photoinduced holes, concurrently, the high oxidation potential and reduction potential of the BiTmFeSbO₇ and the BiTmO₃ were retained. Additionally, a Z-scheme BTBTHP was synthesized by using an ultrasound-assisted solvothermal approach. As a result, the BTBTHP exhibited excellent photocatalytic performance during the degradation process of the sulfathiazole (STZ). The morphological features, composition distribution, photochemistry properties and photoelectric properties of the prepared samples were investigated by using the comprehensive characterization techniques. Under the condition of visible light irradiation, the BTBTHP demonstrated an excellent removal efficiency of 99.50% for degrading the STZ. Contrastive analysis results indicated that the removal efficiency of the STZ by using the BTBTHP was substantially higher than that by using the BiTmFeSbO₇, the BiTmO₃, and the N-doped TiO₂. The removal rate of the STZ by using the BTBTHP was 1.14 times that by using the BiTmFeSbO₇, 1.28 times that by using the BiTmO₃, and 2.71 times that by using the N-doped TiO₂. Moreover, the stability and the reusability of the BTBTHP were verified through five successive photocatalytic cyclic degradation experiments, indicating that the BTBTHP owned potential for the practical application. The active species which was produced by the BTBTHP were identified as hydroxyl radicals (•OH), superoxide anions (•O₂⁻), and photoinduced holes (h⁺) by capturing radicals experiments and electron paramagnetic resonance testing experiments. Therefore, the degradation mechanism and the pathway of the STZ could be more comprehensively elucidated. In summary, this study lays a solid foundation for the development and further research of high efficient Z-scheme heterojunction photocatalysts and offers novel insights into sustainable remediation strategies for the STZ pollution. Full article

Mg-doped gallium oxide films were prepared on single crystal sapphire substrates through radio frequency magnetron sputtering technology, and then AlN films of different thicknesses were deposited on them as passivation layers. Finally, Pt interdigitated electrodes were prepared through mask plate and ion sputtering technology to make metal–insulator–semiconductor–insulator–metal (MISIM) photodetectors. The influence of the AlN passivation layer on the optical properties and photodetection performance of the device was investigated using UV-Vis (ultraviolet-visible absorption spectroscopy) spectrophotometer and a Keith 4200 semiconductor tester. The device’s performance was significantly enhanced. Among them, the MISIM-structured device achieves a responsivity of 2.17 A/W, an external quantum efficiency (EQE) of 1100%, a specific detectivity (D*) of 1.09 × 10¹² Jones, and a photo-to-dark current ratio (PDCR) of 2200. The results show that different thicknesses of AlN passivation layers have an effect on the detection performance of Mg-doped β-Ga₂O₃ films in the UV detection of the solar-blind UV region. The AlN’s thickness has little effect on the bandgap when it is 3 nm and 5 nm, and the bandgap increases at 10 nm. The transmittance of the film increases with the increase in AlN thickness and decreases when the AlN’s thickness increases to 10 nm. The photocurrent exhibits a non-monotonic dependence on AlN thickness at 10 V, and the dark current gradually decreases. The thickness of the AlN passivation layer also has a significant impact on the response characteristics of the detector, and the response characteristics of the device are best when the thickness of the AlN passivation layer is 5 nm. The responsiveness, detection rate, and external quantum efficiency of the device first increase and then decrease with the thickness of the AlN layer, and comprehensive performance is best when the thickness of the AlN passivation layer is 5 nm. The reason is that the AlN layer plays a passivating role on the surface of Ga₂O₃ films, reducing surface defects and inhibiting its capture of photogenerated carriers, while the appropriate thickness of the AlN layer increases the barrier height at the semiconductor interface, forming a built-in electric field and improving the response speed. Finally, the AlN layer inhibits the adsorption and desorption processes between the photogenerated electron–hole pair and O₂, thereby retaining more photogenerated non-equilibrium carriers, which also helps enhance photoelectric detection performance. Full article

High-performance self-powered ultraviolet (UV) photodetectors (PDs) based on mixed-dimensional 3D BiOCl nanosheet array/2D ZnO nanoparticle films heterojunction were fabricated via facile spin-coating and impregnation methods. Under zero bias, compared to the pristine ZnO PD exhibiting a large dark current (≈2 μA) and slow response time (>20 s/>20 s), the optimized 2-BiOCl-ZnO heterojunction PD demonstrated a dramatically suppressed dark current (≈1 nA), along with an ultrahigh on/off ratio (22,748) and a shorter response time (17.44 ms/14 ms) under 365 nm light illumination. This optimized device also achieved a remarkable responsivity of 1.08 A·W⁻¹ and a detectivity of 2.48 × 10¹³ Jones at 354 nm. The built-in electric field formed at the BiOCl-ZnO heterojunction interface, the improved light absorption enabled by the mixed-dimensional heterostructure, and the optimized charge carrier separation and transport within the device were responsible for the enhanced self-powered performance. Due to its fascinating photoelectric properties, this PD was applied as a self-powered signal receiver in a UV optical communication system, demonstrating the ability to achieve efficient and high-speed message transmission. The rational construction of BiOCl-based heterojunction has proved to be an efficient pathway to achieving self-powered photodetection. These results demonstrate that the rational construction of heterojunctions holds great potential for fabricating high-performance PDs. Full article

The promotion and application of a solar photovoltaic thermal (PVT) collector is increasingly favored. In this paper, a solar PVT collector with a serpentine pipe has been investigated by using the double iteration strategy. The simulation results are in good agreement with the experimental data. The effects of ambient temperature, solar irradiance, distance between pipes, pipe diameter and mass flow rate on the thermal efficiency and photoelectric conversion efficiency (PCE) are discussed. Specifically, the results show that with an increase in the ambient temperature, the thermal efficiency of the collectors increases and the PCE decreases. By contrast, as the inlet water temperature decreases, the heat dissipation capacity is enhanced, which in turn both improves its thermal efficiency and PCE. Furthermore, the reduction in the distance between pipes also helps to improve thermal efficiency. However, when the distance between pipes is reduced to 0.1 m, the reduction in the thermal efficiency is not significant. It is worth noting that there exists an optimal solution to the influence of the pipe diameter on the thermal performance of the collector. This implies that the large pipe diameter will reduce the thermal efficiency to some extent. In addition, as the mass flow rate increases, the thermal efficiency is improved, and the plate temperature and outlet water temperature decrease simultaneously, with a greater decrease in outlet water temperature. Full article