Applications Of Silicon Microchannel Plates On Micro-Optical Signal Detection And Supercapacitor Energy Storage

Three-dimensional silicon microchannel plates, as a substrate with high depth-to-width ratio, is under great application potential in the field of micro-optical signal detection and supercapacitor energy storage. The substrate of the supercapacitor based on p-type<100> silicon wafer was fabricated through serial standard MEMS procedures including thermal oxidation, lithography, electrochemical etching, etc. The Si-MCPs were distributed in a pore size of 5×5 μmin square arrays, and the depth is about 200 μm.The typical representative for micro-optical signal detection is the photomultiplier, which has been accomplished through a series of processes including film deposition and surface morphology improvements. The resistance of the photomultiplier has further increased through adjustment and optimization of the process flow, and problems such as surface roughness and cleanliness, lithography alignment and short circuit have been well solved.A nickel layer was made to act as a compact conductive layer, through electroless plating and electrodeposition sequentially, with manganese dioxide later electrodeposited on it as active materials, to be the electrode of the supercapacitor. Then the electrode was packaged with nickel foam and other highly conductive materials, separator and certain electrolyte to be a full supercapacitor. XRD, SEM and EDS methods were to investigate and characterize the micromorphology and structural constituents of MnO2/Ni/Si-MCPs. The electrochemical functions of the electrode and supercapacitor were investigated in electrolytes of 1 mol/L Na2SO4 and 1 mol/L LiClO4-PC, respectively.Cyclic voltammetry, galvanostatic charge/discharge tests and electrochemical impedance spectroscopy are main methods to gauge the basic electrochemical properties of the samples. The MnO2/Ni/Si-MCPs electrode presents good properties that its specific capacitance reaches 0.961 F/cm2 (323.1 F/g). The capacitance retention ratio after 1,000 cycles is 91.1% and the loss after 500 cycles is only 1.4%. The supercapacitor was packaged under the environment of organic electrolyte to avoid the phenomena such as water decomposition, emission of by-products and poor solubility, thus ensuring the normal operation voltage range of the supercapacitor to be 1.2 V. The specific capacitance of the MnO2/Ni/Si-MCPs supercapacitor reaches 0.745 F/cm2(214.1 F/g), the highest energy/power density are 8.6 Wh/kg and 7.0 kW/kg respectively, and after charging, a single supercapacitor device can power a light emitting diode for nearly 2 minutes, indicating considerable energy storage capability.