Using state-of-the-art first principles electronic structure calculations perovskite materials such as organo-metallic halides and CsSnX3 with X = halogen atoms, are being studied for high efficiency solar cells that could provide a headway in new generation photovoltaics. We are also working on nano-structured materials like layered chalcogenides which are graphene-like materials, but unlike graphene they have a finite band gap that can be exploited in making solar cells and switching devices.