Research On Magnetron Sputtering Process And Device Performance Of Microcrystalline Silicon Thin Film Cells

With the consumption of traditional energy and environmental pollution,and the emergence of thin film products such as Han Wall and Han Wa and the popularization of the concept of mobile energy,the photovoltaic industry is developing rapidly.Thin-film solar cells have become the focus of research both at home and abroad due to their universality and the advantages of the realization of building photovoltaic building integration(BIPV).Compared with other thin film solar cells,silicon-based thin film solar cells have the advantages of low cost,high conversion efficiency,and good absorption of poor light.Among them,the biggest advantage of the microcrystalline silicon thin film solar cell is that it has no photo-attenuation(S-W)effect and a wide range of utilization of the solar spectrum.Therefore,microcrystalline silicon thin film solar cells and a-Si:H/?c-Si:H silicon thin film stacked batteries will become the development direction of thin film solar cells.in the future.As the absorption layer of the thin film solar cell,the intrinsic layer is critical to the performance of the solar cell device.In this paper,the intrinsic microcrystalline silicon film was prepared on a transparent conductive glass substrate by magnetron sputtering deposition process.The effect of different deposition processe parameters(sputtering power,substrate temperature,hydrogen/argon mixing ratio)on the optical properties of the silicon film(transmittance and optical band gap),deposition rate,electrical properties(square resistance and conductivity),surface morphology,crystal orientation and crystallinity.were studied.The experimental results showed that when the sputtering power was increased from 100W to 300W,the deposition rate of the film was increased from 7.08nm/min to 14.45nm/min,and the transmittance of the film was continuously reduced.The optical band gap was 1.37eV at 300W,which is the closest to the optimal band gap value of the intrinsic layer of the crystalline silicon thin film battery,which is 1.39eV.The film gradually changed from needle-like growth to columnar growth,from amorphous to microcrystalline.The roughness of the film surface is gradually increased and the crystallization rate increased from 35.4%to 65.6%.The dark conductivity increased with the increase of the crystallization rate of the film,increasing from the order of 10-8Scm-1 to the order of 10-5Scm-1.As the substrate temperature was heated from normal temperature to 300?,the deposition rate first increased and then decreased,the transmittance of the film decreased first and then increased,the optical band gap decreased gradually,and the crystallinity of the film reaches a maximum of 64.2%at 300?:As the flow rate of Ar increased,the deposition rate of the film gradually decreased,and the crystallization ratio of the film was the highest when the H2/Ar mixture ratio was 40 sccm:20sccm,and the dark conductivity of the film was 10-6Scm-1.Considering the properties of the film,the optimal preparation process parameters of the device quality grade microcrystalline silicon film are as follows:sputtering power 300W,substrate temperature 250?,H2/Ar mixing ratio 40sccm:20sccm.At the same time,in view of the high cost and long time preparation of battery devices in the laboratory,in order to study the influence of each layer parameters on the performance of thin film battery devices,this paper uses wxAMPS to simulate thin film cells so as to provide theoretical support for the experiment and optimize the structure of the thin film device.The simulation results showed that the optical band gap of window layer of the PIN-type amorphous silicon thin film solar cell was 2.0eV,the conversion efficiency of the cell was 10.41%when the doping concentration was 1e20cm-3,and the thickness of the intrinsic layer was 400nm.The concentration of the defect state of the intrinsic layer should not exceed le18cm-3,otherwise the performance of the device would deteriorate sharply,and the V-I characteristic curve would be distorted;when the carbonized amorphous silicon layer was inserted between the pi interface,the battery performance could be effectively improved.When the crystallization rate of the intrinsic layer of the PIN type microcrystalline silicon thin film solar cell was 50%,the device performance was the best.For amorphous silicon/microcrystalline silicon laminate(PINPIN type)solar cells,the optimum thickness of the intrinsic layer of the top and bottom cells was matched to 250nm and 2000nm,and the highest conversion efficiency was obtained at 14.82%;When the doping concentration of tunneling composite juntion reached 7×1019cm-3 or more,the photo-generated carriers of the top and bottom batteries could be transported well at the tunneling composite junction.In summary,this paper prepares the device quality microcrystalline silicon film by controlling the different process parameters of the magnetron sputtering method,improves the preparation process of the microcrystalline silicon film,and simulates the device with wxAMPS to design the film system of the device.And the structure is optimized to provide a theoretical basis for the experimental preparation of microcrystalline silicon thin film cells.In this paper,the experimental research and device performance of microcrystalline silicon film prepared by magnetron sputtering provide theoretical reference and theoretical basis for large-area and low-cost production of microcrystalline silicon thin film cells.