Flexible n-Type Abundant Chalcopyrite/PEDOT:PSS/Graphene Hybrid Film for Thermoelectric Device Utilizing Low-Grade Heat

Abstract

Combining inorganic thermoelectric (TE) materials with conductive polymers is one promising strategy to develop flexible thermoelectric (FTE) films and devices. As most inorganic materials tried up until now in FTE composites are composed of scarce or toxic elements, and n-type FTE materials are particularly desired, we combined the abundant, inexpensive, nontoxic Zndoped chalcopyrite (Cu 1−x Zn x FeS 2 , x = 0.01, 0.02, 0.03) with a flexible electrical network constituted by poly(3,4-ethylenedioxythiophene) polystyrenesulfonate (PEDOT:PSS) and graphene for n-type FTE films. Hybrid films from the custom design of binary Cu 1−x Zn x FeS 2 /PEDOT:PSS to the optimum design of ternary Cu 0.98 Zn 0.02 FeS 2 /PEDOT:PSS/graphene are characterized. Compared with the binary film, a 4-fold enhancement in electrical conductivity was observed in the ternary film, leading to a maximum power factor of ∼ 23.7 μW m −1 K −2 . The optimum ternary film could preserve >80% of the electrical conductivity after 2000 bending cycles, exhibiting an exceptional flexibility due to the network constructed by PEDOT:PSS and graphene. A five-leg thermoelectric prototype made of optimum films generated a voltage of 4.8 mV with a ΔT of 13 °C. Such an evolution of an inexpensive chalcopyrite-based hybrid film with outstanding flexibility exhibits the potential for cost-sensitive FTE applications.

Facile Fabrication of N-Type Flexible CoSb3-xTex Skutterudite/PEDOT:PSS Hybrid Thermoelectric Films

“…In addition, to produce uniform films, most inorganic materials are synthesized into nanoparticles using chemical processing, but the number of inorganic materials that can be obtained using the same method is limited. Recently, the hybridized FTE films between the ball-milled chalcopyrite (Cu x Zn 1-x FeS 2 ) and PEDOT:PSS on the polytetrafluoroethylene (PTFE) membrane have been reported and exhibit outstanding flexibility and performance [ 48 ]. This versatile and promising approach to obtaining FTE film could be extended to various inorganic TE materials that present natively attractive TE performance.…”

A facile route to fabricating a crack-free Mg0.99Cu0.01Ag0.97Sb0.99/graphene/PEDOT:PSS thermoelectric film on a flexible substrate

“…However, the decrease of both m and s for the 50 wt% graphene sample is due to the segregation of graphene nanoplates at the particle boundaries, creating new microstructural interfaces and providing extra boundaries. 58,94 The positive Seebeck coefficients at room temperature for all the hybrid films show that the majority of carriers are holes (Fig. 5a).…”

“…3d, which reveals the formation of a dense film. However, the presence of individual MCAS particles (red circle) and clear interfaces (red arrows) of agglomerated graphene is observed, which can be detrimental to the transport of carriers and may lead to a poor s. 58 In contrast, the MCAS/G/P film shows the homogenous distribution of graphene, and no clear graphene interfaces are observed, which is ascribed to the p-p interaction between graphene and PEDOT:PSS, which is further proved by C 1s spectra in Raman measurement. 84 The stacked graphene nanoplates in the hybrid binary film interact with each other or with particles through the van der Waals force.…”

“…3e). 58,84 The elemental distribution and homogeneity of the pure powder and ternary hybrid film are further investigated by EDS (Fig. S6, ESI †).…”

“…An organic-inorganic strategy 9,30,56,57 and an extended approach reported in our previous study are used in the present work. 58 In brief, we used a chemical composition of Mg 0.99 Cu 0.01 Ag 0.97 Sb 0.99 which possesses a broad temperature plateau of ZT above unity as the inorganic matrix, 53 and formed a hybrid material with poly(3,4-ethylenedioxythiophene):poly(4-styrenesulfonate) (PEDOT:PSS). PEDOT:PSS, among the conductive polymers, is the most promising material due to its advantages of water-dispersibility, good conductivity, low-cost, high transparency, and excellent processability.…”