电荷平衡共掺杂实现超掺杂极限和超低热导率

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中文摘要：低导热系数的材料在能源管理中得到了广泛应用,同时突破固体热导率的非晶极限引起了科学家的广泛关注.掺杂是实现低热导率的一种常见策略,它可以提供丰富的散射中心.其中,较重的掺杂剂总是带来较低的声子群速度和较低的热导率.然而,等价的重原子单掺杂的可用元素是有限的.同时,由于电荷不平衡,非等价重掺杂剂的溶解度有限,这限制了其在调控热导率方面的应用.本文在SnS中提出了一种电荷平衡策略,即用Ag+和重Bi3+代替Sn2+,将Ag的掺杂限值从2％提高到3％.Ag和Bi共掺杂增加了点缺陷浓度,同时引入了丰富的边界,在原子尺度和纳米尺度上散射了声子.Ag0.03Bi0.03Sn0.94S的热导率在室温下降低至0.535 W·m-1·K-1,低于SnS的非晶极限0.450 W·m-1.K-1.该策略提供了一种简单的路径,可以在不进行精确结构修改的情况下,提高掺杂极限并在固体中实现低于非晶极限的超低热导率.

外文标题：Charge-balanced codoping enables exceeding doping limit and ultralow thermal conductivity

外文摘要：Materials with low thermal conductivity are applied extensively in energy management,and breaking the amorphous limits of thermal conductivity to solids has attracted widespread attention from scientists.Doping is a common strategy for achieving low thermal conductivity that can offer abundant scattering centers in which heavier dopants always result in lower phonon group velocities and lower thermal conductivities.However,the amount of equivalent heavy-atom single dopant available is limited.Unfortunately,nonequivalent heavy dopants have finite solubility because of charge im-balance.Here,we propose a charge balance strategy for SnS by substituting Sn2+with Ag+and heavy Bi3+,improving the doping limit of Ag from 2％to 3％.Ag and Bi codoping increases the point defect concentration and introduces abundant boundaries simultaneously,scattering the phonons at both the atomic scale and nanoscale.The thermal conductivity of Ag0.03Bi0.03Sn0.94S decreased to 0.535 W·m-1·K-1 at room temperature and 0.388 W·m-1·K-1 at 275 ℃,which is below the amorphous limit of 0.450 W·m-1·K-1 for SnS.This strategy offers a simple way to enhance the doping limit and achieve ul-tralow thermal conductivity in solids below the amorphous limit without precise structural modification.

外文关键词：

charge-balanced codopingheavy atompoint defectgrain boundaryultralow thermal conductivity

作者：

陈龙、王纯、汪琳、王铭浩、朱永春、吴长征

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作者单位：

中国科学技术大学化学与材料科学学院,安徽合肥 230026

中国科学技术大学合肥微尺度物质科学国家研究中心,安徽合肥 230026

合肥综合性国家科学中心能源研究院,安徽合肥 230031

关键词：

电荷平衡共掺杂重原子点缺陷相边界超低热导率

基金：

CAS Project for Young Scientists in Basic ResearchNational Natural Science Foundation of ChinaNational Natural Science Foundation of ChinaNational Natural Science Foundation of ChinaNational Natural Science Foundation of ChinaUSTC Research Funds of the Double First-Class InitiativeNational Key Research and Development Program of ChinaNational Key Research and Development Program of ChinaNational Key Research and Development Program of ChinaNatural Science Foundation of China-Anhui Joint FundOutstanding Youth Foundation of Anhui ProvinceAnhui Provincial Key Research and Development ProjectKey R&D Program of Shandong ProvinceUsers with Excellence Project of Hefei Science Center CASFellowship of the China Postdoctoral Science Foundationopen foundation of the Key Laboratory of the Engineering Research Center of Building Energy Efficiency Control and Evaluatio

项目编号：

YSBR-0702192511021890750U203216112147105YD20600020042022YFA12036002022YFA12036012022YFA1203602U23A201212208085J14202004a0502007602021CXGC0103022021HSC-UE0042022M710141AHJZNX-2023-04

出版年：

2024

DOI：

10.52396/JUSTC-2024-0025

中国科学技术大学学报

中国科学技术大学

中国科学技术大学学报

CSTPCD北大核心

影响因子：0.421

ISSN：0253-2778

年,卷(期)：2024.54(6)