FLEXIBLE THERMOELECTRIC MATERIALS WITH COPPER IODIDE ON TEXTILE DIELECTRIC SUBSTRATES FOR POWERING WEARABLE ELECTRONICS

Abstract

The paper analyses the results of research into the thermoelectric properties of copper iodide layers deposited on flexible dielectric substrates made from various fabric materials. The main object of study was film systems based on copper iodide obtained by the SILAR chemical synthesis method. Such deposition occurs from aqueous solutions at atmospheric pressure, which ensures high technological efficiency of the method. Samples deposited by the SILAR method were studied using scanning electron microscopy, characteristic X-ray radiation analysis, UV-VIS spectroscopy, X-ray structural and thermoelectric studies. It has been shown that precipitation from aqueous solutions allows the production of copper γ-iodide films with internal nanostructure elements. In such samples, the band gap width typical for iodide is observed. Its confirming the production of CuI semiconductor layers. Separately, it is shown that the proposed method of sample synthesis provides the creation of a composite consisting of a fabric base, a layer of nanocellulose, and copper iodide itself. The high efficiency of the created structures is demonstrated, which also retain their flexible properties. Issues of mechanical stability of film systems and the development of methods to increase their resistance to bending and abrasion are analysed. Methods for creating stable functional layers on the surface of cotton and polyester fibres are considered, and the possibility of using nanocellulose hydrogel to prevent CuI cracking during actual operation is established. The maximum specific thermoelectric power output of the created nanocomposite samples is 15.6 μW/cm2. This value is one of the best among modern solid-state miniature, flexible, and textile thermoelectric materials.