Highly near-infrared-transparent perovskite solar cells and their application in high-efficiency 4-terminal perovskite/c-Si tandems

In this contribution the development of highefficiency planar semi-transparent perovskite solar cells (STPSCs) for tandem applications is presented. The ST-PSC absorber layer, and electron and hole transport layers were processed using spin coating. The near-infrared (NIR) transmission of the ST-PSC is optimized by improving ITO material quality and tuning the thickness of component layers in cells for optimal light management, leading to a high NIR transmittance of about 93%. In combination with a SunPower IBC cell of 23.8% single-junction efficiency, a 4-terminal (4T) perovskite/c-Si tandem cell efficiency of 26.1% is achieved. In combination with a metal-wrap-through n-PERT c-Si cell laminate of 18.6% efficiency, a 4T perovskite/c-Si tandem cell efficiency of 24.1% is demonstrated, showing that a very significant efficiency gain can be obtained on lower performance c-Si cells.