It is estimated that around one sixth of industrial energy usage is wasted as heat. In order to maximize energy efficiency, the waste heat represent a viable resource to reduce overall electricity demand, helping to mitigate CO2 emissions associated with the waste heat. One strategy for using waste heat would be to generate electrical energy with the use of Thermoelectric generators (TEGs).
TEGs are devices, which generate an electrical current driven by a difference in temperatures. TEGs consist of a hot side and a cold side and the difference in temperature between the two sides results in a potential difference (voltage) and current flow, and therefore the generation of electrical power. Until recently, thermoelectric materials capable of producing efficient TEGs at room temperatures, have been based on alloys of rare-Earth elements such as bismuth and tellurium which have draw- backs such as high cost of production, scarcity, and toxicity.
Very recent research has seen the emergence of organic thermoelectric materials which have advantages over inorganic materials, in that they are low cost, light weight and can be processed from solution at low temperatures, meaning they are less energy intensive to produce. This also means that manufacturing technologies such as printing produce organic TEGs over large areas, further reducing costs, but also leading to the possibility of flexible, building-integrated, or even wearable thermoelectric devices.
This project seeks to investigate the thermoelectric properties of potential candidate organic and polymer materials, to investigate improvements in materials' properties gained via process improvements, doping of pure materials, and the fabrication of organic/inorganic nanocomposites. It will also look at novel inorganic materials capable of being processed from solution such as intermetallics and perovskite-structured materials.
The primary objective of the project is to identify materials that are capable of being printed from solution in order to fabricate efficient TEGs on flexible substrates. Once suitable materials have been identified, processing conditions will be optimized and thermoelectric devices will be built and tested. We will also fabricate flexible TEG/photovoltaic tandem devices with the aim of harvesting waste heat from the PV devices under test conditions to generate electrical power photovoltaically and thermoelectrically in the same device.