Improving the performance of textured silicon solar cells through the field‐effect passivation of aluminum oxide layers and up‐conversion via multiple coatings with Er/Yb‐doped phosphors

摘要

Summary This paper examines the influence of field‐effect passivation (from a coating of aluminum oxide) in conjunction with up‐conversion (from multiple coatings containing Er/Yb‐doped phosphors) on the performance of silicon solar cells. Note that the phosphors were applied to the rear surface of the cells. The surface morphology of the coatings was characterized by scanning electron microscopy and the chemical composition of Er/Yb‐doped phosphors coating was examined using energy‐dispersive X‐ray spectroscopy. The fluorescence emissions of the coatings were examined using photoluminescence and optical image measurements. We examined the influence of field‐effect passivation on dark current‐voltage as well as photo‐current density and external quantum efficiency (EQE). Improvements in photovoltaic performance after applying coatings containing Er/Yb‐doped phosphors were estimated in terms of EQE and conversion efficiency. The field‐effect passivation of Al2O3 and up‐conversion provided by Er/Yb‐doped phosphors resulted in EQE enhancements over a wavelength range of 600 to 1050 nm. Field‐effect passivation was shown to enhance the conversion efficiency by 1.77% (from 16.91% to 17.21%), up‐conversion enhanced conversion efficiency by 2.9% (from 17.21% to 17.71%), and a combination of field‐effect passivation and up‐conversion enhanced conversion efficiency by 4.73% (from 16.91% to 17.71%).