Perovskite/InGaAs tandem cell exceeding 29% efficiency via optimizing spectral splitter based on RF sputtered ITO/Ag/ITO ultra-thin structure

Abstract

In this paper, the optimization, elaboration and characterization of an efficient spectral beam splitter based on a simple RF sputtered ITO/Ag/ITO (IAI) ultra-thin multilayer structure are presented. An experimental investigation assisted by Genetic Algorithm (GA) metaheuristic optimization was carried out to achieve high-performance spectral splitter for tandem solar cell applications. The RF magnetron sputtering method was used to elaborate the optimized IAI structure. The optical and structural properties of the sputtered splitter were also analyzed using UV–Vis-IR spectroscopy and X-ray diffraction (XRD) measurements. It is found that the elaborated splitter structure offers 84% of transparency and a high reflectance of 87% with an optimum cut-off wavelength of 800 nm. This is attributed to the design approach, which leads to promote spectral splitting mechanism by inducing efficient optical modulation. Interestingly, a new Figure of Merit (FoM) parameter, which evaluates the optical splitting performances is proposed. Moreover, a new Perovskite/InGaAs tandem cell is proposed and analyzed to show the impact of the elaborated spectrum splitter on the solar cell efficiency. It is revealed that the investigated solar cell exhibits an improved efficiency approaching 30%. The latter value far surpasses that provided by Perovskite tandem cells. These results indicate that our spectrum splitting approach can open a new pathway towards designing high-performance tandem photovoltaic devices.