Study On Micro-Nano Structures And Electron-Selective Contacts In PEDOT:PSS/Silicon Hybrid Solar Cells

With the increasing attention to new energy sources in various countries,the development of solar cells has followed the trend of the times,and their inexhaustible energy characteristics and relatively mature theoretical and technological basis have made solar cells widely popular.Organic/inorganic hybrid solar cells have attracted the interest of a wide range of researchers because of their technical basis of crystalline silicon solar cells,low cost,and simple fabrication process.The highest reported efficiency of silicon-based hybrid solar cells has reached 17%,but its efficiency is still a certain distance compared with that of crystalline silicon solar cells.Therefore,in order to further improve the efficiency of Si-based hybrid solar cells,the following studies are conducted to investigate the light absorption,interfacial contact properties,and back-side carrier transport.The specific work of this paper consists of the following three parts:The etching process of silicon nanowires was investigated,and the reflectance and external quantum efficiency(EQE)of two etching methods,drop etched nanowires and backside protected etched nanowires,were discussed.The experiments showed that the backside protected etching method has a better effect on the current gain of silicon-based hybrid solar cells than the drop etched nanowire method.The flow properties of PEDOT:PSS on silicon micro-nano structures were investigated,and the density of silicon nanowires was varied by building a silicon nanowire model so that PEDOT:PSS obtained different contact masses at different silicon nanowire densities.By building a pyramid model to simulate two different contact cases of infiltration and non-infiltration,the variation of the contact angle at the bottom of the pyramid was investigated in the infiltration and non-infiltration cases.The effect of backside electron-selective contact layers on the performance of silicon-based hybrid solar cells was investigated using wxAMPS software.The effects of two electron-selective contact layers,tin oxide(SnO2)and titanium oxide(TiO2),on the back contact electric field are discussed,because SnO2 and TiO2 have matching conduction band energy levels and deep valence band energy levels compared to silicon,so they can effectively transport electrons blocking the holes and allowing better separation of carriers at the interface.The simulation results show that cells with two electron-selective contact layer structures,SnO2 and TiO2,have higher short-circuit currents and open-circuit voltages than the basic cell structure of silicon-based hybrid solar cells.