Honeycomb structure is extraordinarily effective to trap light,and the efficiency of solar cell with this texture is as high as 24.4%.In this paper,plasma immersion ion implantation and acid etching are applied to tex...Honeycomb structure is extraordinarily effective to trap light,and the efficiency of solar cell with this texture is as high as 24.4%.In this paper,plasma immersion ion implantation and acid etching are applied to texture multi-crystalline silicon.Surface reflectivity and surface morphology are investigated by UV–Vis–NIR spectrophotometer and field emission scanning electron microscopy,respectively.We found that random nano-honeycomb structures have been formed on silicon surface.The weighted average reflectance is 7.68%from 300 to 1,100 nm wavelength region.We obtained honeycomb-textured solar cells following standard fabrication protocol.These solar cells show obvious better performance in short circuit current density([5.4%)and efficiency(*0.8%absolute)compared with acid-textured cell,while other performance parameters,such as open circuit voltage and fill factor,are not deteriorated.展开更多
Invasive neural probes are one of the most critical components in the intracortical neural signal recording system.However,they can cause brain damage and tissue response during and after implantation.Thus,neural prob...Invasive neural probes are one of the most critical components in the intracortical neural signal recording system.However,they can cause brain damage and tissue response during and after implantation.Thus,neural probes with high flexibility,biocompatibility,and simple implantation methods are required in brain research.Here we present a novel approach to fabricating a multilayer flexible tassel-type neural probe using low-cost maskless laser direct-write lithog-raphy,combined with straightforward release and assembly methods to prepare a whole implantation system.The probe has 32 recording electrodes with an area of 8×8μm^(2),arranged into two rows of different depths and 16 separated shanks,aiming at the neural signal recording in an extensive range.Polyimide and gold are used as the insulating and conductive layers,respectively.With the help of a polyethylene glycol(PEG)coating,the tassel structure was mechanically enhanced for successful implantation,and our morphology characterization showed that the diameter of the coated probe was less than 50μm.Mechanical property tests also proved that it had the necessary stiffness for brain implantation.Afterwards,electrochemical tests were carried out,which showed that the probe had a rather low impedance after a simple gold electroplating.Finally,in vivo experiments demonstrated our probe can be successfully used in neural recording.展开更多
基金supported by the National Natural Science Foundation of China(607227003 and 61106060)the Instrument Developing Project of the Chinese Academy Sciences(YZ200755)
文摘Honeycomb structure is extraordinarily effective to trap light,and the efficiency of solar cell with this texture is as high as 24.4%.In this paper,plasma immersion ion implantation and acid etching are applied to texture multi-crystalline silicon.Surface reflectivity and surface morphology are investigated by UV–Vis–NIR spectrophotometer and field emission scanning electron microscopy,respectively.We found that random nano-honeycomb structures have been formed on silicon surface.The weighted average reflectance is 7.68%from 300 to 1,100 nm wavelength region.We obtained honeycomb-textured solar cells following standard fabrication protocol.These solar cells show obvious better performance in short circuit current density([5.4%)and efficiency(*0.8%absolute)compared with acid-textured cell,while other performance parameters,such as open circuit voltage and fill factor,are not deteriorated.
基金funded by the National Defense Science and Technology Innovation Special Zone–Spark Project(20-163-00-TS-009-152-01)the National Natural Science Foundation of China(U20A20227,61974030)+1 种基金the National Key R&D Program of China(2019YFA0709504)the National Natural Science Foundation of China(31900719).
文摘Invasive neural probes are one of the most critical components in the intracortical neural signal recording system.However,they can cause brain damage and tissue response during and after implantation.Thus,neural probes with high flexibility,biocompatibility,and simple implantation methods are required in brain research.Here we present a novel approach to fabricating a multilayer flexible tassel-type neural probe using low-cost maskless laser direct-write lithog-raphy,combined with straightforward release and assembly methods to prepare a whole implantation system.The probe has 32 recording electrodes with an area of 8×8μm^(2),arranged into two rows of different depths and 16 separated shanks,aiming at the neural signal recording in an extensive range.Polyimide and gold are used as the insulating and conductive layers,respectively.With the help of a polyethylene glycol(PEG)coating,the tassel structure was mechanically enhanced for successful implantation,and our morphology characterization showed that the diameter of the coated probe was less than 50μm.Mechanical property tests also proved that it had the necessary stiffness for brain implantation.Afterwards,electrochemical tests were carried out,which showed that the probe had a rather low impedance after a simple gold electroplating.Finally,in vivo experiments demonstrated our probe can be successfully used in neural recording.
