DROP-IT proposes the development of novel lead-free and stable perovskites (LFPs). Specifically, crystalline structures beyond conventional ABX3 compounds, double-perovskites and rudorffites, will be computationally screened and chemically synthesized with superior properties. DROP-IT will develop highly pioneering lead free perovskites (in bulk and nanoscale) by low-cost, high throughput, sustainable, large-scale fabrication techniques on flexible substrates to revolutionize future power, lighting and communication systems. DROP-IT technology will be based on: (1) Theoretical screening of different LFP compound families and chemical synthesis of most suitable ones in the form of nanocrystals and polycrystalline thin films, (2) Formulation of specific and suitable inks of these materials for (3) Inkjet printing of thin films on flexible substrates and (4) Development of stable optoelectronic and photonic devices as proofs-of-concept.