Replacing expensive silver with inexpensive copper for the metallization of silicon wafer solar cells can lead to significant reductions in material costs associated with cell production, but the susceptibility of the Cu material to oxidation remains a challenging issue to solve. In this study, we investigate copper metallization of Indium Tin Oxide surfaces to define copper grid electrodes for heterojunction cells. We propose a novel laser-induced selective metallization (LISM) method to fabricate large-scale copper electrodes for heterojunction solar cells at low cost.
View Article and Find Full Text PDFMicro/nano-textured metal or metal oxide surfaces that are naturally superhydrophilic will spontaneously transform into hydrophobic even superhydrophobic after being exposed to ambient air due to the adsorption of airborne organics. This fast wettability transition not only affects the true evaluation of surface wettability but also deteriorates the application performance. Albeit the mechanisms responsible for the wettability transition have been clarified, there is no universal method to recover the initial superhydrophilicity, and how the surface morphology affects the wettability transition is still unclear.
View Article and Find Full Text PDFIn this work, copper circuits were fabricated on flexible polyimide (PI) substrates by high repetition rate femtosecond laser-induced selective local reduction of copper oxide nanoparticles (CuO NPs). The effects of laser pulse energy and laser scanning velocity on the quality of the copper circuit were studied. By optimizing laser processing parameters, we prepared a Cu circuit of a line width of 5.
View Article and Find Full Text PDFIn this study, we observe and study the early evolution of cavitation bubbles generated during pulsed laser ablation of titanium targets in different liquid environments utilizing a high-resolution stroboscopic shadowgraphy system. A hydrodynamic model is proposed to calculate the early pressure changes within the bubble and in the surrounding fluid. Our results show that the cavitation bubble is a low-pressure region that is bounded by a high-pressure fluid lamina after the incipient stage, and its evolution is primarily affected by the liquid density.
View Article and Find Full Text PDFPrecision glass molding is a revolutionary technology for achieving high precision and efficient manufacturing of glass aspheric lenses. The material properties of glass, including elastic modulus and viscosity, are highly dependent on temperature fluctuations. This paper aims to investigate the effect of elastic modulus on the high-temperature viscoelasticity of glass and the accuracy of the finite element simulation of the molding process for glass aspheric lenses.
View Article and Find Full Text PDFBecause of the poor lighting conditions at night time, visible images are often fused with corresponding infrared (IR) images for context enhancement of the scenes in night vision. In this paper, we present a novel night-vision context enhancement algorithm through IR and visible image fusion with the guided filter. First, to enhance the visibility of poorly illuminated details in the visible image before the fusion, an adaptive enhancement method is developed by incorporating the processes of dynamic range compression and contrast restoration based on the guided filter.
View Article and Find Full Text PDF