NEST, Scuola Normale Superiore and Istituto Nanoscienze-CNR, Piazza San Silvestro 12, Pisa, I-56127, Italy.
Universitá di Pisa, Dipartimento di Fisica, Largo Bruno Pontecorvo, 3, Pisa, 56127, Italy.
Adv Sci (Weinh). 2023 Mar;10(7):e2204120. doi: 10.1002/advs.202204120. Epub 2023 Jan 25.
Thermoelectric polyelectrolytes are emerging as ideal material platform for self-powered bio-compatible electronic devices and sensors. However, despite the nanoscale nature of the ionic thermodiffusion processes underlying thermoelectric efficiency boost in polyelectrolytes, to date no evidence for direct probing of ionic diffusion on its relevant length and time scale has been reported. This gap is bridged by developing heat-driven hybrid nanotransistors based on InAs nanowires embedded in thermally biased Na -functionalized (poly)ethyleneoxide, where the semiconducting nanostructure acts as a nanoscale probe sensitive to the local arrangement of the ionic species. The impact of ionic thermoelectric gating on the nanodevice electrical response is addressed, investigating the effect of device architecture, bias configuration and frequency of the heat stimulus, and inferring optimal conditions for the heat-driven nanotransistor operation. Microscopic quantities of the polyelectrolyte such as the ionic diffusion coefficient are extracted from the analysis of hysteretic behaviors rising in the nanodevices. The reported experimental platform enables simultaneously the ionic thermodiffusion and nanoscale resolution, providing a framework for direct estimation of polyelectrolytes microscopic parameters. This may open new routes for heat-driven nanoelectronic applications and boost the rational design of next-generation polymer-based thermoelectric materials.
热电型聚电解质作为自供电生物兼容电子设备和传感器的理想材料平台正在兴起。然而，尽管离子热扩散过程在聚电解质中提高热电效率具有纳米尺度的特性，但迄今为止，尚无关于在相关长度和时间尺度上直接探测离子扩散的证据。通过开发基于嵌入热偏置 Na 功能化（聚）氧化乙烯的 InAs 纳米线的热驱动混合纳米晶体管来弥合这一差距，其中半导体纳米结构充当纳米级探针，对离子物种的局部排列敏感。研究了离子热电门控对纳米器件电响应的影响，研究了器件结构、偏置配置和热刺激频率的影响，并推断出热驱动纳米晶体管操作的最佳条件。从纳米器件中出现的滞后行为分析中提取出聚电解质的微观参数，如离子扩散系数。所报道的实验平台同时实现了离子热扩散和纳米级分辨率，为直接估计聚电解质的微观参数提供了框架。这可能为热驱动的纳米电子应用开辟新途径，并推动下一代基于聚合物的热电材料的合理设计。
