Study On Efficiency Improvement Of Perovskite Solar Cells Based On Nanostructure

Perovskite solar cells have attracted the worldwide interest due to their unique properties.Within a decade,the power conversion efficiency of single-junction perovskite solar cells has surpassed 24.2%,outclassing the initial3.8%.To further improve the conversion efficiency of perovskite solar cells,it is necessary to not only promote the material quality and the fabrication technique but also improve the light management.In this dissertation,to enhance the optical absorption,nanostructures were introduced to CH₃NH₃PbI₃ films with a thickness of100 nm.The interaction of light with nanostructured CH₃NH₃PbI₃ films was simulated and optimized by the finite element method,using COMSOL Multiphysics software package.The main contents are as follows:1.The optical absorption of a CH₃NH₃PbI₃ film without any nanostructure?denoted as“plane perovskite”?was simulated and the reflectance,transmittance and ideal conversion efficiency were obtained.Then,the sinusoidal surface nanostructure was designed.By optimizing its sinusoidal amplitude and period,it was found that the ideal conversion efficiency can reach 19.0%,where is about 24%higher than that of plane perovskite.2.The cylindrical hole array was designed on the perovskite film.It was found that the optical absorption was enhanced in the whole wavelength range.By optimizing the period and filling factor,the ideal conversion efficiency of the cylindrical hole array can reach 28.5%,where is about 86%higher than that of plane perovskite.3.The sinusoidal surface was introduced to the cylindrical hole arrays with a period of 800 nm.Two kinds of composite nanostructures were studied.One is the composite structure with a cylindrical hole and a single sinusoidal surface and the other is that with a cylindrical hole and two adjacent sinusoidal surfaces.For both composite structures,the sinusoidal amplitude and the fill factor were optimized.In the first composite structure,the maximum ideal conversion efficiency can reach26.8%,which is about 75%higher than that of plane perovskite but is about 6%lower than that of the optimized cylindrical hole array.In the second composite structure,when the light incidents from the upward side and downward side,the maximum ideal conversion efficiency can reach about 32.7%and 33.1%,which are18%higher than that of optimized cylindrical hole array and 114%and 116%higher than that of plane perovskite.These results indicate that nanostructures can significantly enhance the light absorption in perovskite solar cells and provide good references to improve their energy conversion efficiency and environmental friendliness.