The aim of CHEOPS is to develop very low-cost but highly performing photovoltaic (PV) devices based on the emerging perovskite (PK) technology. At lab scale (20%. But only few attempts at upscaling have been made, yielding significantly reduced efficiencies 14% stable for aperture area in modules >15x15cm2). This will demonstrate the potential of PK as a very low-cost technology (target 29% on 2x2 ...