硫族化合物SrPbSe_(2):具有潜力的新型热电材料  

Chalcogenides SrPbSe_(2):A potential thermoelectric material

作　　者：白树林 张潇 赵立东 Shulin Bai;Xiao Zhang;Li-Dong Zhao(Tianmushan Laboratory,Hangzhou 311115,China;School of Materials Science and Engineering,Beihang University,Beijing 100191,China)

机构地区：[1]天目山实验室,杭州311115 [2]北京航空航天大学材料科学与工程学院,北京100191

出　　处：《科学通报》2025年第6期755-766,共12页Chinese Science Bulletin

基　　金：国家杰出青年科学基金(51925101);国家自然科学基金(52002042,52250090,51571007,51772012,12204156);北京市杰出青年科学基金(JQ18004);高等学校学科创新引智计划(B17002);科学探索奖资助。

摘　　要：近年来,开发高性能硫族热电材料对于提高能源转换效率和实现可持续能源利用具有重要意义.本文基于密度泛函理论和玻尔兹曼传输理论,全面探索了新型硫族化合物SrPbSe_(2)的电子结构、力学、热传输、电传输和热电性能.电子结构分析表明,SrPbSe_(2)是一种窄带隙、直接带隙半导体.弹性常数和声子谱计算表明,SrPbSe_(2)是韧性材料,具有力学和动力学稳定性.此外,SrPbSe_(2)中Pb^(2+)的孤对电子6s2呈现立体化学活性,使得Pb原子引起配位原子周围的晶格发生扭曲,增强了晶格非简谐性.结果表明,SrPbSe_(2)的低热导率主要由八面体PbSe6局部晶格畸变引起Pb–Se弱键合和产生更多的声子散射中心所造成.最后,通过高通量筛选,结合多种载流子散射机制,评估了SrPbSe_(2)的相关热电参数,预测p型和n型SrPbSe_(2)分别具有最大ZT值1.31和0.95.本文的研究结果为未来开发SrPbSe_(2)基热电材料提供了一定的理论见解和指导.Thermoelectric(TE)materials enable the direct conversion of thermal energy into electrical energy,offering a promising avenue for clean energy generation and addressing the global energy crisis.This technological advancement has significant potential to mitigate the adverse environmental impacts associated with carbon-based energy consumption.However,the widespread application of TE materials has been substantially constrained by their relatively low efficiency,often quantified by the dimensionless figure of merit(ZT).The ZT value is determined by the interplay of several TE parameters,including Seebeck coefficient,electrical conductivity,electronic thermal conductivity and lattice thermal conductivity.Overcoming the competitive relationship between Seebeck coefficient and electrical conductivity to achieve a higher power factor(PF)can enable the optimization of TE performance in semiconductors with inherently low thermal conductivity.Over the past decades,extensive theoretical and experimental studies have proposed strategies to enhance PF and reduce thermal conductivity,including band and strain engineering,defect and alloying engineering,and materials genome engineering.Recently,the computational materials science has highlighted the fundamental characteristics of high-performance TE materials,emphasizing the wide bandgap,complex structure,anisotropic multi-band structure,and ultralow thermal conductivity.TE materials represented by chalcogenides have been shown to have broad application prospects in recent years.PbSe is a TE material renowned for its exceptional performance in mid-to-high temperature applications.With the increasing demand for high-performance,low-cost TE materials,PbSe-based compounds have made significant progress in recent years,with peak ZT of~1.8 and room ZT of~0.7 for n-type compounds and with peak ZT of~2.0 and room ZT of~0.8 for ptype compounds.Studies have shown that alkaline earth metals significantly impact the TE properties of PbSe-based compounds.Experimentally,trace amounts of a

关 键 词：密度泛函理论 硫族化合物 电子结构 力学性能 低热导率 

分 类 号：TB34[一般工业技术—材料科学与工程]