Selective Chemical Vapour Deposition for Production of Thermoelectric Micro-Generators for Energy Harvesting

热电微型发电机是一种固态装置，可以提供恒定的电力来源。它们有许多非常有利的特点，即没有机械部件会磨损，需要很少的维护，使用寿命长，不会产生任何排放。固态热电设备基于两种现象之一：塞贝克效应，可用于发电(能量收集)，以及帕尔蒂埃效应，用于电子冷却或加热。为了制造功能热电器件，n型掺杂材料通过温差串联和热并联连接到p型掺杂材料，从而使电流在两者之间流动。碲化铋系热电材料非常适合于近室温的应用，包括无线传感。通过STFC支持的最新研究，我们开发了一系列新的分子前驱体化合物，可用于化学气相沉积制备(n型)碲化铋和(p型)碲化锑的高质量薄膜。不同寻常的是，我们的前体和基于CVD的系统允许非常有选择地将材料沉积到光刻图案衬底的特定区域。该项目的重点是与包括一家热电设备公司和一家专业前体制造商在内的主要利益攸关方密切合作，利用我们的前体和基于CVD的方法的独特功能，从而显著降低制造热电微型发电机的生产成本。由于实际生产成本占每个热电发电机单位成本的大部分，降低这一成本是当务之急，以使这些微型发电机设备能够渗透到新的和更大的市场。对我们的CVD生产的热电微型发电机的关键热电性能的验证和基准测试是这项工作的核心，这也将提供必要的关键数据，以评估将我们的基于CVD的方法用于TE微致冷器用于未来应用的前景，例如微处理器的芯片冷却。

Thermoelectric micro-generators are solid state devices that can provide constant sources of electricity. They have a number of very favourable features, i.e. no mechanical parts that can wear out, require little maintenance, have long lifetimes and produce no emissions. Solid-state thermoelectric devices are based upon one of two phenomena, the Seebeck effect, which can be used for power generation (energy harvesting), and the Peltier effect for electronic cooling or heating. In order to produce a functional thermoelectric device, an n-type doped material is connected electrically in series and thermally in parallel across a temperature differential to a p-type doped material, so that current flows between the two. Bismuth telluride based thermoelectric materials are very well suited for near room temperature applications, including wireless sensing. Through recent research supported by STFC, we have developed a new series of molecular precursor compounds which can be used in chemical vapour deposition to produce high quality thin films of (n-type) bismuth telluride and (p-type) antimony telluride. Unusually, our precursors and CVD-based system allows the materials to be deposited very selectively onto specific areas of lithographically patterned substrates. The focus of this project is to work closely with key stakeholders, including a thermoelectric device company and a specialist precursor manufacturer, to exploit the unique features of our precursors and CVD-based approach so that the production costs for manufacture of thermoelectric micro-generators can be reduced significantly. Since the actual production costs account for the majority of the unit cost per thermoelectric generator, reducing this is a high priority to allow penetration of these micro-generator devices into new and larger markets. Validation and benchmarking of the key thermoelectric properties of our CVD-produced thermoelectric micro-generators is central to the work, and this will also provide the key data necessary to evaluate the prospect of using our CVD-based approach for TE micro-coolers for future applications such as on-chip cooling of microprocessors.