A high-efficient photo-thermoelectric coupling generator of cuprous iodide

Abstract

Thermoelectric (TE) energy converters have attracted great interest due to their maintenance-free, long-life, and high-reliability properties. However, improving the output power of TE devices remains a huge challenge. In this work, a high-efficient photo-TE coupling generator based on cuprous iodide (CuI) film is proposed to increase the output power of TE devices. Here, CuI film was prepared by the successive ionic layer adsorption and reaction method. The influence of the photovoltaic (PV) effect on the TE output voltage of CuI film was investigated by an analysis of the experimental results. The results showed that the output voltage of the photo-TE coupling generator had a maximum increment of 83.47% at 343 K compared to the sum of TE and PV voltages. The increase in the output voltage was mainly because of the PV effect rather than the TE effect, while the photo-generated electrons also induce a considerable change in the TE figure of merit. Hence, the strategy proposed in this work might be a potential approach to further improve the output performance of other TE materials.

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].…”

“…At the same time, the continuous pursuit of costeffective manufacturing is increasingly redirecting the research efforts to the chemical solution-based coating approaches, because they do not require expensive high-vacuum processing chambers. 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).…”

“…This creates obstacles for their semiconductor applications, especially for flexible electronics and thermoelectrics [5]. In contrast, the chemical solution deposition process Successive Ionic Layer Adsorption and Reaction (SILAR) does not require annealing after deposition [6,9,10], which makes it possible to obtain conductive thermoelectric copper(I) iodide films on various rigid plates or flexible plastic substrates.…”