Research On The Construction And Performance Of Flexible Graphene/silicon-based Heterojunction Solar Cells

Flexible graphene/silicon?Gr/Si?solar cells have attracted much attention due to their simple structure,simple preparation process,no need for conventional high temperature diffusion,and the unique consumables,light weight,portability,and wider application of flexible devices.However,the flexible graphene/ultra-thin silicon solar cell has a complicated preparation process,expensive equipment,and failure to obtain stable high conversion efficiency,which hinders its large-scale application.At present,there are mainly silicon-based ultra-thinning processes,the ultra-thin planar silicon base has low light absorption rate,and the existing preparation process does not match the preparation of flexible batteries.In view of the immature silicon-based ultra-thinning process and the low light absorption rate of ultra-thin planar silicon,this paper proposes Si-Cu?NO₃?₂-H₂O₂-HF metal copper auxiliary etching instead of traditional KOH alkaline etching.Silicon-based thinning-texturing treatment;in view of the problem that the existing preparation process does not match the preparation of flexible batteries,this paper proposes a novel flexible graphene/silicon inverted pyramid solar cell structure and its preparation process.In this paper,the morphology,etch rate,and minority carrier lifetime of single crystal silicon were characterized by scanning electron microscopy,ultraviolet spectrophotometer and minority carrier lifetime tester for Si-Cu?NO₃?₂-H₂O₂-HF etching.The photoelectric properties of the novel flexible graphene/silicon inverted pyramid solar cells were characterized by solar cell I-V test system,and the effect of the structure on the performance of graphene/silicon solar cells was investigated.The TiO₂ film was prepared by sol-gel method,and the photoelectric properties of the new flexible titanium dioxide/graphene/silicon inverted pyramid solar cell were characterized by solar cell I-V test system.The new flexible graphene/silicon inverted pyramid solar cell photovoltaic was explored.The impact of performance.In addition,a tungsten oxide film with a thickness of 14 nm was prepared by magnetron sputtering equipment,and its morphology and thickness were characterized by atomic force microscopy,field emission scanning electron microscopy and secondary mass spectrometry,respectively.The photoelectric properties of a novel flexible graphene/tungsten oxide film/silicon inverted pyramid solar cell were characterized.The effect of tungsten oxide film on the novel flexible graphene/silicon inverted pyramid solar cell was studied.The main research contents and conclusions are as follows:?1?Compared with KOH alkaline etching,Si-Cu?NO₃?₂-H₂O₂-HF etching greatly shortens the thinning time and saves cost.The thinning rate of crystalline silicon is the alkali etching rate.12.2 times.In addition,the surface of the crystalline silicon is nanotextured at the same time as the thinning,which increases the absorption rate of light,and the reflectance to light is only 10%.?2?The preparation process of the novel flexible graphene/silicon inverted pyramid solar cell is simple,and the preparation can be completed at room temperature.The test results of the solar cell I-V test system show that the various photoelectric performance parameters have different degrees of decline in addition to the short-circuit current density(J_sc).The reason for the analysis may be that although the introduction of nanostructures enhances the solar cell's ability to capture light and improve light utilization,with the introduction of a large number of unsaturated dangling bonds introduced by nanostructures,interface defects are greatly increased,increasing the reverse of the battery.Saturation current,carrier recombination is serious.?3?The introduction of tungsten oxide?WO₃?film leads to the bending of the surface energy band of graphene/silicon,and the transfer of electrons from the silicon group to the graphene does not affect the transfer of holes,effectively preventing carrier recombination.Reducing the reverse dark saturation current and improving the photoelectric performance of the solar cell,the photoelectric conversion efficiency of the new flexible graphene/silicon inverted pyramid solar cell with a working area of 17mm² was increased from 1.24%to 2.8%.In addition,the introduction of titanium dioxide?TiO₂?film significantly increases the absorption rate of light,which leads to different degrees of improvement in the performance parameters of a series of solar cells,such as open circuit voltage,fill factor,and short-circuit current density,without chemical doping.The photoelectric conversion efficiency of the new flexible graphene/silicon inverted pyramid solar cell has increased to 4.3%.