Our team has a prime research interest in the solution-based synthesis and thin film deposition along with the understanding of low-cost energy materials to harness the solar energy for electricity production. The synthesis or deposition of nanomaterials is an active academic and, particularly, ongoing applied research in nanotechnology. The desirable properties of nanomaterials make them promising in various sizes, such as in exploring new frontiers of chemistry and solid-state physics. Over the time, improvements in nanomaterials and thin film deposition methods eventually have empowered diverse technological innovations in areas ranging from magnetic recording media, semiconductor devices, light-emitting diodes (LEDs), optical layers, hard coatings on cutting tools, energy harvest materials (i.e., thin-film photovoltaics) to energy storage (i.e., batteries, supercapacitors) devices. The control of structure, thickness, morphology, and stability of nanomaterials based thin-film is crucial for their diverse applications. The morphology and stability of thin films strongly hinges on the deposition or synthesis techniques employed. Our group currently focuses on investigation of two materials classes namely Cu-based chalcogenide materials and perovskites for their applications in solar devices. We employ range of synthesis and deposition techniques for development of these energy materials. High vacuum deposition techniques like plasma-enhanced chemical vapor deposition (PE-CVD), hot-wire chemical vapour deposition (HW-CVD), and radio-frequency (RF) magnetron sputtering is normally used for thin film deposition. Solution-based synthesis such as hot injection method, chemical bath deposition (CBD), and electrodeposition are also employed. We focus on the development of novel, sustainable energy materials along with their detailed characterization for energy and optoelectronic applications. Our work focuses on the development of sustainable emerging materials for energy and optoelectronic applications such as photovoltaic, water-splitting, and light-emitting devices. We currently investigate two materials classes for their use in such devices: Halide-based perovskites and complex chalcogenide semiconductors. Perovskites and chalcogenides both hold the great potential for low-cost and sustainable next-generation devices. We investigate each of these areas with focus on the designing of novel materials as well as the understanding of the fundamental chemical, structural, optical, and electronic properties. Our work targets the development of appropriate film/crystal growth techniques along with the fabrication of novel device structures involving these new interesting identified materials to create outstanding device performance.