Optimal thermoelectric figure of merit of Si/Ge core-shell nanowires

作     者：Kaike Yang Andres Cantarero Angel Rubio Roberto D'Agosta 

作者机构：Nano-Bio Spectroscopy Group and ETSF Scientific Development Center Departamento de Fisica de Materiales Universidad del Pais Vasco UPV/EHU San Sebastian 20018 Spain Instituto de Ciencia de Materiales Universidad de Valencia Valencia 46071 Spain Ikerbasque Basque foundation for Science Bilbao 48013 Spain 

出 版 物：《Nano Research》 (纳米研究（英文版）)

年 卷 期：2015年第8卷第8期

页      面：2611-2619页

核心收录：

学科分类：080903[工学-微电子学与固体电子学] 081803[工学-地质工程] 0809[工学-电子科学与技术（可授工学、理学学位）] 08[工学] 0818[工学-地质资源与地质工程] 080501[工学-材料物理与化学] 0805[工学-材料科学与工程（可授工学、理学学位）] 080502[工学-材料学] 

基　　金：support from CONSOLIDER INGENIO 2010: NANOTherm Diputacion Foral de Gipuzkoa the European Research Council Advanced Grant DYNamo Spanish Grants Grupos Consolidados UPV/ EHU del Gobierno Vasco Ikerbasque and MAT2012-33483 

主　　题：thermoelectric properties Seebeck coefficient silicon and germanium core-shell nanowires 

摘      要：We investigate the thermoelectric energy conversion efficiency of Si and Ge nanowires, and in particular, that of Si/Ge core-shell nanowires. We show how the presence of a thin Ge shell on a Si core nanowire increases the overall figure of merit. We find the optimal thickness of the Ge shell to provide the largest figure of merit for the devices. We also consider Ge core/Si shell nanowires, and show that an optimal thickness of the Si shell does not exist, since the figure of merit is a monotonically decreasing function of the radius of the nanowire. Finally, we verify the empirical law relating the electron energy gap to the optimal working temperature that maximizes the efficiency of the device.