Promising transparent and flexible thermoelectric modules based on p-type CuI thin films—A review

Copper-Enriched Nanostructured Conductive Thermoelectric Copper(I) Iodide Films Obtained by Chemical Solution Deposition on Flexible Substrates

“…Copper(I) iodide (CuI) is a promising semiconductor with band gap 𝐸 𝑔 equal to 3.1 eV, which has been widely used in heterojunction diodes, thermoelectric (TE) devices, photodetectors, solar cells and transistors [1][2][3][4][5][6][7]. By an appropriate doping, CuI provides high hole mobility up to 44 cm 2 V −1 s −1 , and p-type conductivity up to 280 S • cm −1 with a wide range of hole concentrations (from 10 16 to 10 20 cm −3 ) [5].…”

“…The copper(I) iodine films with stable cubic structure 𝛾-CuI can be grown by a variety of physical vapor and chemical solution methods at near room temperatures [2,5,7]. To date, the best thermoelectric figures of merit (ZT ) have been obtained for CuI films prepared by the solid iodination of copper layers on glass substrates (𝑍𝑇 ≈ 0.22) [7], an,d for CuI films deposited on a flexible polyethylene, terephthalate (PET) substrates by reactive sputtering (𝑍𝑇 ≈ 0.21) [2]. The above has accelerated the realization of the flexible thermoelectric devices for body-heat-driven wearable electronics, as well as for on-chip cooling or power reversion of miniaturized chips [5].…”

“…Additionally, the chemical solution deposition processes has other advantages, such as large area atmospheric deposition capabilities, easy operation, and component adjustment [5,6]. But till now, CuI thin films synthesized by chemical solution processes such as spin-coating, spraying, ink-jet printing, and vacuum-assisted filtration of a CuI suspension, contain unwanted impurities from the precursor solutions, have insufficient electrical conductivity 𝜎 [2,5,8], and, as a result, their thermoelectric power factor 𝑃 = 𝜎𝑆 2 is small or even negligible (here, 𝑆 is the Seebeck coefficient). Moreover, CuI thin films obtained by spincoating, spraying and ink-jet printing require annealing after growth.…”

“…The aim of this work is to study the morphology, chemical composition, crystal structure, and charge transport in nanostructured conducting thermoelectric copper(I) iodide films obtained by the SILAR method to create flexible thermoelectric materials. Since the choice of substrate material in the manufacture of thin-film thermoelectric devices plays an important role in their output thermoelectric parameters [2], herein, for CuI deposition by the SILAR method, we used two polymer substrates important for application in flexible devices: polyethylene terephthalate and polyimide (PI) (Kapton R ○type). Thus, the objects of our research are flexible thin-film CuI/PET and CuI/PI samples with nanostructured CuI layers fabricated by the SILAR method.…”

Flexible Environmentally Friendly Thermoelectric Material Made of Copper (1) Iodide and Nanocellulose for Green Energy

“…To be truly green, thermoelectric materials must have a minimal impact on the environment and human health throughout their entire life cycle from raw material extraction to disposal. Copper (1) iodide (CuI) is a novel promising p-type thermoelectric semiconductor with a large thermoelectric figure of merit ZT of 0.22 [2][3][4][5]. At the same time, according to [6,7], CuI exhibits good antibacterial activity against infections caused by broad-spectrum bacteria and can be used to destroy organic pollutants in water.…”