A realistic approach to increase the efficiency of photovoltaic (PV) devices above the Shockley-Queisser single-junction limit is the construction of tandem devices. PERCISTAND focuses on the development of advanced materials and processes for all thin film perovskite on chalcogenide tandem devices. This tandem configuration is at an early stage of development today. The PERCISTAND emphasis is on 4-terminal tandem solar cell and module prototype demonstration on glass substrates, but also current- and voltage-matched 2-terminal proof-of-concept device structures are envisaged. Key research activities are the development and optimization of top wide band gap perovskite and bottom low band gap CuInSe2 devices, suitable transparent conductive oxides, and integration into tandem configurations. The focus is on obtaining high efficiency, stability and large-area manufacturability, at low production cost and environmental footprint. Efficiency target is 30 % at cell level, and 25 % at module level. Reliability and stability, tested in line with International Electrotechnical Commission (IEC) standards, must be similar as commercially available PV technologies. High manufacturability means that all technologies applied are scalable to 20×20 cm2, using sustainable and low-cost materials and processes. The cost and environmental impact will be assessed in line with International Organization for Standardization (ISO), and must be competitive with existing commercial PV technologies. Such a tandem device significantly outperforms not only the stand-alone perovskite and chalcogenide devices, but also best single-junction silicon devices. The development will be primarily on glass substrates, but also applicable to flexible substrates and thus interesting for building integrated photovoltaic (BIPV) solutions, an important market for thin film PV. Hence, the outcome has high potential to strengthen and regain the EU leadership in thin film PV research and manufacturing.