Solution processed thermoelectric materials for large area applications

据估计，大约六分之一的工业能源消耗被浪费为热量。为了最大限度地提高能源效率，废热是一种可行的资源，可以减少总体电力需求，有助于减少与废热相关的二氧化碳排放。使用废热的一种策略是使用热电发电机（TEG）产生电能。TEG是一种通过温差驱动产生电流的设备。TEG由热侧和冷侧组成，两侧之间的温差导致电势差（电压）和电流，从而产生电力。直到最近，能够在室温下产生有效的TEG的热电材料一直基于稀土元素如铋和碲的合金，其具有诸如高生产成本、稀缺性和毒性的缺点。最近的研究已经看到有机热电材料的出现，其具有优于无机材料的优势，因为它们成本低，重量轻，并且可以在低温下从溶液中加工，这意味着它们的生产能耗较低。这也意味着，印刷等制造技术可以大面积生产有机TEG，从而进一步降低成本，但也为柔性、建筑一体化甚至可穿戴热电设备提供了可能性。本项目旨在研究潜在候选有机和聚合物材料的热电性能，研究通过工艺改进、纯材料掺杂、以及有机/无机纳米复合材料的制备。它还将研究能够从溶液中加工的新型无机材料，如金属间化合物和钙钛矿结构材料。该项目的主要目标是确定能够从溶液中打印的材料，以便在柔性基板上制造高效的TEG。一旦确定了合适的材料，将优化加工条件，并建造和测试热电装置。我们还将制造灵活的TEG/光伏串联装置，目的是在测试条件下从光伏装置中收集废热，以在同一装置中以光电和热电方式产生电力。

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.