Design And Fabrication Of Photovoltaic Devices Based On Titanium Dioxide Spherical Nanostructured Arrays

Solar energy is a renewable energy which can be used on a large scale.Currently,commercial solar cells are mainly silicon-based,however,the main challenge to silicon-based photovoltaic devices is that silicon materials are not strong absorbers for sunlight.Therefore,improvement for the light absorption of silicon absorption layer is the key to realize high efficiency silicon-based solar cells.The dielectric sub-wavelength structure has special optical properties,and the utilization rate of solar energy can be improved by coupling the sunlight to the active region of photovoltaic devices through local resonance mode and waveguide resonance mode.Therefore,the preparation of sub-wavelength structure based on dielectric materials on the upper surface of silicon has become a current research hotspot.In this paper,the effect of titanium dioxide?TiO₂?spherical nanostructure array on the performance of solar cells is simulated by using the coupling software of Comsol Multiphysics based on finite element analysis,and then the simulation data is processed by Matlab programming software to obtain the photovoltaic performance parameters.Finally,the silicon-based solar cells with TiO₂ spherical nano-array structures are prepared and tested for photovoltaic performance according to the simulation design.Firstly,the basic principle of nanostructure trapping efficiency is introduced,the basic idea of the design of spherical nanostructure array is proposed,and TiO₂ is determined as the material of nanosphere,which will guide the preparation of silicon-based solar cells with TiO₂ spherical nano-array structure.Secondly,using the COMSOL Multiphysics simulation software,models of different diameters,diameter-to-pitch ratio and super-hemispherical TiO₂ nanosphere array on the surface of silicon base are designed with crystalline silicon as substrates.The reflectivity,transmittance and absorptivity of the models are calculated under AM1.5 as the light source.Then,based on the calculated absorption data,the photoelectric conversion efficiencies of the above structures are calculated by Matlab software,and compared with the silicon-based solar cell without the trapping structure.Thirdly,TiO₂ nanospheres are prepared by sol-gel method,and the TiO₂ nanospheres with good dispersibility and uniform particle size are prepared by adjusting the content of tetrabutyl titanate in ethylene glycol,the ratio of precursor to acetone,aging time,etc.Finally,the TiO₂ nanospheres are arranged on the surface of crystalline silicon solar cells by oil-water self-assembly method.The crystalline silicon solar cells based on TiO₂nanosphere array are prepared and tested for the battery performance.