Investigation of highly efficient narrowband gap graphene quantum dots based nano composite for thermoelectric and super capattery applications

Abstract

The global energy supply is expected to triple by 2055, according newline to the World Energy Council. To meet this pressing need and prevent the newline depletion of fossil fuels, sophisticated energy conversion and storage newline technologies such as solar cells, thermoelectric devices, fuel cells, batteries newline and supercapacitors have been developed. Thermoelectric and supercapattery newline are the two energy conversion and energy storage promising present and newline future technologies. Over the past few decades, these technologies have newline attracted greater research interest from both academia and industry. newline This thesis is focused on novel and original research in the area of newline chalcogenide semiconductor quantum dots and graphene quantum dots, for newline the energy conversion and energy storage applications. Quantum dots are newline three dimensionally confined structures in nanometre range (1 100 nm). Due newline to decrease in size, some new phenomena like enhanced surface activity and newline size controlled, tuning energy gap occur. These properties make them very newline attractive candidates for developing thermoelectric devices and supercapaterry newline devices as well as for other potential applications. newline The present study involves the synthesis of Lead Sulphide (PbS) newline and Graphene Oxide (GO) based nanostructures namely, PbS nanoparticles newline (PbS NPs), PbS Quantum Dots (PbS QDs), GO, Graphene Quantum Dots newline (GQDs) and Lead Sulphide- Graphene Quantum Dots (PbS-G QDs) newline nanocomposite for the thermoelectric and supercapattery applications. The newline experimental methods of co-precipitation, chemical bath, modified Hummer s, newline probe sonication and solvothermal methods were adopted for the synthesis newline part. The synthesized materials were studied for supercapattery and newline thermoelectric applications. newline