基于功能基元序构策略提升Ag_(2)Se基柔性热电薄膜的性能  

Enhanced Performance of Ag_(2)Se-Based Flexible Thermoelectric Films Based on Functional Units Ordering Strategy

作　　者：王子兴 李佳佳 刘莹 蔡克峰 WANG Zixing;LI Jiajia;LIU Ying;CAI Kefeng(School of Materials Science and Engineering,Tongji University,Shanghai 201804,China)

机构地区：[1]同济大学材料科学与工程学院,上海201804

出　　处：《硅酸盐学报》2024年第1期218-228,共11页Journal of The Chinese Ceramic Society

基　　金：国家自然科学基金(92163118,51972234)。

摘　　要：热电材料是一种能够实现热能和电能相互转换的清洁能源材料。近年来,随着可穿戴电子设备的蓬勃发展,柔性热电材料成为研究热点。热电材料中载流子和声子传输表现出强耦合特性,严重制约热电性能的提升。功能基元序构是一种优化材料性能的有效策略。在材料中构筑不同作用机制的功能基元,并将功能基元进行序构,同时增强功能基元间的协同效应,可以有效地提升材料的性能。本工作主要以硒化银基柔性热电薄膜为例,介绍功能基元序构和功能基元间协同效应对电、声输运性能和柔性的作用机制。Thermoelectric (TE) materials as one of clean energy materials can realize the direct conversion between heat and electricity.Flexible TE films have attracted recent attention because they can be used to fabricate flexible TE generators (f-TEGs) to replace batteries that need to be charged or replaced frequently to power rapidly developing wearable electronic devices.Bi_(2)Te_(3)-based films exhibit the optimum TE performance at room temperature (RT),but Bi_(2)Te_(3)-based films are easy to oxidize,and Te is expensive,rare,and toxic,so suitable alternatives need to be explored.Silver selenide (Ag_(2)Se) is a narrow bandgap semiconductor and has a superior TE performance at RT.Furthermore,compared with element Te,element Se is less toxic and more abundant.However,the TE properties of Ag_(2)Se are still lower than that of Bi_(2)Te_(3).This review summarized the mechanism of improving the TE properties and flexibility of Ag_(2)Se by functional unit order strategy,and provided a route to enhance the TE properties and flexibility of Ag_(2)Se.Typical strategies for improving the z T values of Ag_(2)Se-based films include the introduction of secondary phase,defect engineering,stoichiometry manipulation,etc..However,charge carrier and phonon transport in TE material are strongly coupled with each other,seriously restricting the improvement of TE performance.The functional unit order is an effective strategy to optimize the performance of materials.Functional units with different roles constructed orderly in materials can enhance a synergistic effect between functional units and thus improve the performance.For Ag_(2)Se-based flexible TE films,the effect of functional unit ordering and the synergetic effect between functional units on the electronic,phonon transport,and flexibility were discussed.The S-doped Ag_(2)Se film shows a power factor~954μW·m^(-1)·K~(-2 )at 300 K and superior flexibility (94.4%of the original electrical conductivity was preserved after bending for 2 000 times around a rod with a radius of 4 mm)

关 键 词：热电薄膜 硒化银 功能基元序构 柔性 

分 类 号：TB34[一般工业技术—材料科学与工程]