SnX(X=S, Se)/P3HT复合薄膜制备及其热电应用

Preparation and thermoelectric application of SnX (X= S, Se)/P3HT composite films

摘要:

将无机纳米材料硫化亚锡（SnS）纳米带或硒化锡（SnSe）纳米片与有机聚合物3-己基取代聚噻吩（P3HT）复合制备了两类无机/有机复合薄膜SnS/P3HT和SnSe/P3HT，结合XRD、SEM、EDS和Raman表征，考察了SnS或SnSe含量（以P3HT质量为基准的百分数，下同）对SnS/P3HT或SnSe/P3HT电导率（σ）、塞贝克系数（S）和功率因子（PF）的影响。结果表明，SnS纳米带或SnSe纳米片与P3HT的复合均为物理混合。SnS(4%)/P3HT的PF最大，为3.33 μW/(mK2)，相比P3HT薄膜的2.80 μW/(mK2)提高了18.9%；SnSe纳米片在SnSe/P3HT中的分散性差，其团聚程度随SnSe含量增加而增强，导致其σ大幅度降低，未能提高PF，因此不具备热电应用价值。最后，本文研究了SnS/P3HT复合薄膜在柔性热电器件中的应用。SnS(4%)/P3HT的柔性器件在外负载电阻（Rload）为1.5 kΩ时的最大输出功率（Pmax）为16.7 nW；当弯曲半径4 mm时，SnS(4%)/P3HT复合膜经过1000次的重复弯曲后，其电阻相对偏差值为23.15%。

Abstract:

Two types of inorganic/organic composite films, SnS/P3HT and SnSe/P3HT, were prepared by combining the inorganic nanomaterials tin sulfide (SnS) nanoribbons or tin selenide (SnSe) nanosheets with the organic polymer 3-hexyl substituted polythiophene (P3HT). Using XRD, SEM, EDS, and Raman characterization techniques, the effect of the content of SnS or SnSe on the conductivity (σ), Seebeck coefficient (S), and power factor (PF) of the composite films was examined. The results indicate that the composite materials are physical mixtures of SnS nanoribbons or SnSe nanosheets and P3HT. Among the various compositions tested, the film containing 4% SnS nanoribbons and P3HT (SnS(4%)/P3HT) exhibits the highest power factor, 3.33 μW/mK2, which is 18.9% higher than that of the pure P3HT film (2.80 μW/mK2). The SnSe nanosheets are poorly dispersed within the SnSe/P3HT composite. Moreover, the degree of aggregation increases with the higher content of SnSe, resulting in a significant decrease in σ and failure to improve PF. So, the SnSe/P3HT composite film has no value for thermoelectric applications. Finally, this article studies the application of SnS/P3HT composite films in flexible thermoelectric devices. The SnS(4%)/P3HT flexible device achieved a maximum output power (Pmax) of 16.7 nW at an external load resistance (Rload) of 1.5 kΩ. After being subjected to 1000 cycles of repeated bending at a 4mm radius, the resistance relative deviation value of the SnS(4%)/P3HT composite film is 23.15%.