A Solution Processable High‐Performance Thermoelectric Copper Selenide Thin Film

Abstract

A solid-state thermoelectric device is attractive for diverse technological areas such as cooling, power generation and waste heat recovery with unique advantages of quiet operation, zero hazardous emissions, and long lifetime. With the rapid growth of flexible electronics and miniature sensors, the low-cost flexible thermoelectric energy harvester is highly desired as a potential power supply. Herein, a flexible thermoelectric copper selenide (Cu Se) thin film, consisting of earth-abundant elements, is reported. The thin film is fabricated by a low-cost and scalable spin coating process using ink solution with a truly soluble precursor. The Cu Se thin film exhibits a power factor of 0.62 mW/(m K ) at 684 K on rigid Al O substrate and 0.46 mW/(m K ) at 664 K on flexible polyimide substrate, which is much higher than the values obtained from other solution processed Cu Se thin films (<0.1 mW/(m K )) and among the highest values reported in all flexible thermoelectric films to date (≈0.5 mW/(m K )). Additionally, the fabricated thin film shows great promise to be integrated with the flexible electronic devices, with negligible performance change after 1000 bending cycles. Together, the study demonstrates a low-cost and scalable pathway to high-performance flexible thin film thermoelectric devices from relatively earth-abundant elements.

High Performance Thermoelectric Materials: Progress and Their Applications

“…For example, a membrane with good thermal conductivity and biocompatibility can be applied on the surface of the device to increase the biocompatibility to the surrounding tissues. [247,252,262,263] To achieve this, TE devices can be deposited [317] or printed as films [240,325] or on flexible bases such as paper (Figure 13c), [326] or assembled as arrays on the bases using multiple TEG modules via advanced microfabrication techniques (Figure 13d,e). For the practical applications, the TEGs benefit from flexibility and ease of tailoring [307,312,323,324] to obtain adaptability and processability.…”

Large-Area Laying of Soft Textile Power Generators for the Realization of Body Heat Harvesting Clothing

“…Although flexible TEGs can be manufactured through various processes [13][14][15][16][17][18][19][20][21][22], each of the aforementioned conventional technologies has limitations such as cost, toxicity, complicated processes, yield issues on products, and difficulty in integrating with actual clothing. Furthermore, the power of TEGs from the conventional processes is restricted by the small generator size.…”

Thin Film Thermoelectric Materials: Classification, Characterization, and Potential for Wearable Applications

“…Then, through the wet-deposition method, this ink solution was covered on flexible substrates evenly (Figure 1h,i). The Cu 2 Se thin film fabricated by this route exhibits a power factor of 0.62 mW cm −1 K −2 at 684 K [27]. Furthermore, the TE generators working in room temperature range will be a significant breakthrough in the development of wearable and portable devices.…”

“…The p-type and n-type spherical powders of TE thin films with average size 200 µm on glass substrates result in the good electrical performance, which reach 15.9 µW cm −1 K −2 in power factor of p-type thin film and 21.5 µW cm −1 K −2 in power factor of the n-type thin film. However, when comparing to the Bi-Te system thin film TE devices, less cost Zn based thin films and Cu based thin films have been studied recently [27,28,34,35]. 2017; (j) The photograph of a CuI thin film sample deposited on polyethylene terephthalate (PET) substrate with a bending angle; (k) Schematic illustration for the power output measurement of the CuI/PET single-leg TE device; and, (l) The example infrared image taken during one of the measurements.…”

“…Furthermore, bulk TE materials encountered a bottleneck in practical application, such as limitation of shape and stagnancy of performance, which restricted the development of intelligent TE devices. In contrast, thin film TE materials are lightweight and low cost and are easily synthesized on different kinds of substrates, which offer possibility in the development of novel TE devices meeting bendable and miniature requirements [25][26][27][28].…”