A kind of high-performance pedot-tellurium nanoparticle composite film and its preparation method

Abstract

The invention relates to a high-performance PEDOT-tellurium nanoparticle composite film and a preparation method thereof. The composite film comprises: a PEDOT film and tellurium nanoparticles uniformly distributed in the PEDOT film, and the particle diameter of the tellurium nanoparticles is 2-300nm , the content of tellurium nanoparticles is 1.1wt%-33.9wt%. The invention can effectively improve the Seebeck coefficient of the material under the extremely low addition amount of tellurium element.

Description

technical field [0001] The invention relates to a high-performance PEDOT-Te nano particle composite film and a preparation method thereof, belonging to the field of energy materials. Background technique [0002] Conductive polymer thermoelectric materials have better ductility, processability and lower cost than traditional inorganic thermoelectric materials. Poly 3,4-ethylenedioxythiophene (PEDOT) and its derivatives are currently the most excellent conductive polymers. However, the thermoelectric performance of PEDOT is restricted by its low Seebeck coefficient, and its application is still limited. At present, there are two main methods to increase the Seebeck coefficient. One is to adjust the concentration of carriers through reduction methods, such as electrochemical reduction (Energy & Environmental Science, 2013, 6, 788) and reducing agent reduction (Organic Electronics, 2015, 17, 151 ), etc., the reduction method can greatly increase the Seebeck coefficient, but it...

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Problems solved by technology

[0003] However, although the composite tellurium nanorods are promising, there are still two serious shortcomings in the current preparation process, which restrict the application of PEDOT

[0004] First of all, the current method of synthesizing composite thin films is a typical two-step method. Tellurium nanorods must be synthesized first, and then mixed with PEDOT:PSS. During the separation and transfer of tellurium nanorods, a large amount of oxidation occurs, and there are Residual surfactant, which greatly reduces the goodness of the contact between elemental tellurium and PEDOT. During the mixing process, tellurium nanorods will also settle and agglomerate in the PEDOT:PSS solution, which seriously affects the uniformity of the film. The surface of the film is extremely rough and easily cracked

In addition, PEDOT:PSS solution, as a water-soluble precursor, is widely used in the preparation of composite materials, but its structure is affected by the bulky anion PSS, and the decrease in order makes the degree of carrier localization intensified, which limits the The improvement of Seebeck coefficient, as a matrix, its performance is not ideal, but high-performance small molecule doped PEDOT, such as PEDOT:Tos, cannot be applied to the traditional two-step synthesis of PEDOT-Te because of its insolubility composite material

[0005] Secondly, the reason why tellurium can form a nanorod structure is that under the guidance of the hexagonal structure, the traditional dilute solution synthesis process (sodium tellurite + ascorbic acid) allows sufficient time and space for further growth of tellurium nanocrystals into larger The rod-like structure usually has a diameter of hundreds of nm and a length of several μm, and such large-sized particles, due to the effect of phonon dragging, have significantly lower efficiency in increasing the Seebeck coefficient, usually under the condition of adding 90wt% Effective performance improvement can be achieved. Such a high addition of tellurium material will undoubtedly cause huge damage to the ductility and processability of the polymer, and seriously waste precious crustal resources, which violates the original intention of preparing composite materials.

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