RESUMEN
Wearable electronic devices have emerged as a pivotal technology in healthcare and artificial intelligence robots. Among the materials that are employed in wearable electronic devices, organic thermoelectric materials possess great application potential due to their advantages such as flexibility, easy processing ability, no working noise, being self-powered, applicable in a wide range of scenarios, etc. However, compared with classic conductive materials and inorganic thermoelectric materials, the research on organic thermoelectric materials is still insufficient. In order to improve our understanding of the potential of organic thermoelectric materials in wearable electronic devices, this paper reviews the types of organic thermoelectric materials and composites, their assembly strategies, and their potential applications in wearable electronic devices. This review aims to guide new researchers and offer strategic insights into wearable electronic device development.
RESUMEN
Organic electrochemical transistors (OECTs) offer significant advantages in electrophysiological applications, primarily due to their ability to facilitate ionic-to-electronic conversion and establish a direct interface with the surrounding aqueous environments by using organic mixed ionic-electronic conductors. This study employs a side-chain free n-type conducting polymer, poly(benzodifurandione) (PBFDO), as the channel material in OECTs to scrutinize the interplay between various ion concentrations in electrolytes and the conjugated polymer and to assess their subsequent impact on device performance. Our findings reveal that PBFDO-based OECTs demonstrate superior transfer characteristics, attributed to their high conductivity and remarkable stability in aqueous solutions. Interestingly, the ion concentration does not alter the electronic band structure of PBFDO during the doping process, but a high-salt-concentration electrolyte could accelerate the electrochemical process compared to its counterparts. Furthermore, the diluted solution significantly enhances the surface roughness and decreases the crystalline coherence length of the film compared with concentrated solutions. A quantitative analysis utilizing an electrochemical quartz crystal microbalance discloses that the electrolyte ions penetrate the PBFDO film, inducing the absorption of a fraction of water molecules, which is pronounced in diluted solutions and negligible in their concentrated counterparts. This notable swelling of the polymer in diluted solutions potentially hampers the transport of charge carriers, consequently diminishing the OECT performance. This research elucidates a direct correlation between microstructure alterations and device performance during operation, paving the way for the optimization of ionic and electronic conductivity in polymers to foster the development of high-performance organic electronic devices.
RESUMEN
N-doping of perylene diimides (PDIs) to create stable radical anions is significant for harvesting photothermal energy due to their intensive absorption in the near-infrared (NIR) region and non-fluorescence. In this work, a facile and straightforward method has been developed to control the doping of perylene diimide to create radical anions using organic polymer polyethyleneimine (PEI) as a dopant. It was demonstrated that PEI is an effective polymer-reducing agent for the n-doping of PDI toward the controllable generation of radical anions. In addition to the doping process, PEI could suppress the self-assembly aggregation and improve the stability of PDI radical anions. Tunable NIR photothermal conversion efficiency (maximum 47.9%) was also obtained from the radical-anion-rich PDI-PEI composites. This research provides a new strategy to tune the doping level of unsubstituted semiconductor molecules for varying yields of radical anions, suppressing aggregation, improving stability, and obtaining the highest radical anion-based performance.