Thermoelectric Inks and Power Factor Tunability in Hybrid Films through All Solution Process

Abstract

Thermoelectric (TE) materials can have a strong benefit to harvest thermal energy if they can be applied to large areas without losing their performance over time. One way of achieving large-area films is through hybrid materials, where a blend of TE materials with polymers can be applied as coating.Here, we present the development of all solution-processed TE ink and hybrid films with varying contents of TE Sb 2 Te 3 and Bi 2 Te 3 nanomaterials, along with their characterization. Using (1-methoxy-2-propyl) acetate (MPA) as the solvent and poly (methyl methacrylate) as the durable polymer, large-area homogeneous hybrid TE films have been fabricated. The conductivity and TE power factor improve with nanoparticle volume fraction, peaking around 60−70% solid material fill factor. For larger fill factors, the conductivity drops, possibly because of an increase in the interface resistance through interface defects and reduced connectivity between the platelets in the medium. The use of dodecanethiol (DDT) as an additive in the ink formulation enabled an improvement in the electrical conductivity through modification of interfaces and the compactness of the resultant films, leading to a 4−5 times increase in the power factor for both p-and n-type hybrid TE films, respectively. The observed trends were captured by combining percolation theory with analytical resistive theory, with the above assumption of increasing interface resistance and connectivity with polymer volume reduction. The results obtained on these hybrid films open a new low-cost route to produce and implement TE coatings on a large scale, which can be ideal for driving flexible, large-area energy scavenging technologies such as personal medical devices and the IoT.

On the electrophoretic deposition of Bi2Te3 nanoparticles through electrolyte optimization and substrate design

“…There is evidence that dithiol influences the electronic properties of NP films, demonstrated by ethane dithiol treatment of PbS NP films resulting in nearly a tenfold increase in mobility [23]. A similar trend of reduction of resistance was shown recently by the use of single thiols in the organic-inorganic hybrid TE films [22].…”

“…Electrical conductivity (σ) was estimated thereof. Details of the measurement set-up are presented in our previous paper [22]. The S is estimated through the integral method, where one end of the sample is held at a fixed temperature while the other end is heated through the temperature range of interest.…”

Recent Progress in Colloidal Quantum Dot Thermoelectrics

“…The use of CQDs enables compatibility with a variety of low-temperature upscalable printing techniques for manufacturing TEGs onto arbitrary substrate materials. [48][49][50] Such TEG technologies are promising for self-powered electronic applications in the rapidly emerging internet-of-things (IoT) device ecosystem. [51][52][53][54][55][56][57] Herein, we review recent progress in the science and technology of semiconducting CQDs-based thermoelectrics.…”

Improving the Performance of Paper-Based Dipole Antennas by Electromagnetic Flux Concentration

“…In fact, the 5G’s connectivity will soon expand the mobile IoT, paving the way for rapid innovation across several industries and markets, including driverless cars, smart cities and homes, logistics monitoring, on-body wireless communication/energy harvesting, among others . By 2030, a multibillion IoT technology users are expected, thus the networks that provide digital–physical communications represent a great opportunity in the development of new advanced functional materials, shaping the ongoing digitalization of both society and economy …”

“…2 By 2030, a multibillion IoT technology users are expected, thus the networks that provide digital−physical communications represent a great opportunity in the development of new advanced functional materials, shaping the ongoing digitalization of both society and economy. 3 Smart sensors, smart antennas, and intelligent processors represent the backbone of IoT technology. 4 Apart from the sophisticated sensing and processing platforms, the choice of an appropriate antenna systems is particularly critical for the successful implementation of the IoT solutions, as this component is responsible for sending/receiving the information generated by any source/sensor to the processing tools of the IoT.…”