Chalcopyrite based semiconductor materials are being extensively studied for solar and photodetector applications. Most of them being direct bandgap semiconductors with earth abundant, non toxic and cost effective elements have opened the possibilities for low cost, flexible and large scale optoelectronic applications. In this respect materials like Cu2SnS3, Cu2ZnSnS4, Cu2CoSnS4 and Cu3BiS3 are being investigated. Both thin films and nanostructures are synthesized using solution processable methods, for coating onto flexible and large area substrates. Inorganic-organic hybrid devices using the nanostructures are fabricated for optoelectronic applications. Primary focus is on obtaining good quality films by various techniques and its fundamental understanding of the current transport mechanisms, semiconductor heterojunctions and interfaces, etc.