金属学报, 2026, 62(6): 1137-1146 DOI: 10.11900/0412.1961.2025.00269

研究论文

Al掺杂对CuInTe2热电性能的影响

杨二阔,1, 张泽宇1, 王亚松1, 彭威1, 历长云1, 李广书2, 康慧君,2, 王同敏,2

1 中国石油大学(北京)克拉玛依校区 工学院 克拉玛依 834000

2 大连理工大学 材料科学与工程学院 辽宁省凝固控制与数字化制备技术重点实验室 大连 116024

Influence of Al Doping on Thermoelectric Properties of CuInTe2

YANG Erkuo,1, ZHANG Zeyu1, WANG Yasong1, PENG Wei1, LI Changyun1, LI Guangshu2, KANG Huijun,2, WANG Tongmin,2

1 School of Engineering, China University of Petroleum-Beijing at Karamay, Karamay 834000, China

2 Key Laboratory of Solidification Control and Digital Preparation Technology (Liaoning Province), School of Materials Science and Engineering, Dalian University of Technology, Dalian 116024, China

通讯作者: 康慧君,kanghuijun@dlut.edu.cn,主要从事热电材料和铜合金研究;王同敏,tmwang@dlut.edu.cn,主要从事有色金属及其复合材料、热电功能材料、高熵合金研究杨二阔,yangerkuo@cupk.edu.cn,主要从事机器学习和热电材料研究

收稿日期: 2025-09-16   修回日期: 2026-03-09  

基金资助: 国家自然科学基金项目(52271025)
国家自然科学基金项目(51927801)
国家自然科学基金项目(U22A20174)
辽宁省科技计划项目(2023JH2/101700295)
大连科技创新项目(2023JJ12GX021)
克拉玛依市创新杰出青年人才项目(XQZX20230103)

Corresponding authors: KANG Huijun, professor, Tel:(0411)84709500, E-mail:kanghuijun@dlut.edu.cn;WANG Tongmin, professor, Tel:(0411)84706790, E-mail:tmwang@dlut.edu.cn;YANG Erkuo, Tel:(0990)6633320, E-mail:yangerkuo@cupk.edu.cn

Received: 2025-09-16   Revised: 2026-03-09  

Fund supported: National Natural Science Foundation of China(52271025)
National Natural Science Foundation of China(51927801)
National Natural Science Foundation of China(U22A20174)
Science and Technology Planning Project of Liaoning Province(2023JH2/101700295)
Innovation Foundation of Science and the Technology of Dalian(2023JJ12GX021)
Innovation Outstanding Young Talent Program of Karamay(XQZX20230103)

作者简介 About authors

杨二阔,男,1994年生,博士

摘要

CuInTe2的弱电导率和相对高的晶格热导率导致其较低的热电优值(ZT值)和转换效率,从而阻碍了其在热电领域的商业化应用。本工作通过固态反应和热压烧结法制备了一系列Al掺杂的CuIn1-xAlxTe2化合物,研究了Al掺杂量对微观结构和热电性能的影响。结果表明,Al掺杂明显增大了载流子浓度,从而提升了电性能。同时,Al掺杂引入了取代型点缺陷、位错、应变波动和CuInAl4Te8纳米析出相,抑制了声子运输,从而实现晶格热导率的下降。最终,在823 K时,CuIn0.8Al0.2Te2达到最小晶格热导率(0.72 W/(m·K)),同时达到ZT值峰值(0.88),比基体提升了115%。CuIn0.8Al0.2Te2在323~823和523~823 K间的平均ZT值分别为0.34和0.60,分别比基体增加了127%和122%。CuIn1-xAlxTe2化合物ZT值和平均ZT值的明显提升表明了CuInTe2 In位掺杂的有效性。

关键词: CuInTe2; 热电材料; 掺杂; Seebeck系数

Abstract

The low electrical conductivity exhibited by CuInTe2, coupled with its relatively high lattice thermal conductivity, results in a suboptimal thermoelectric figure of merit (ZT) and conversion efficiency, thereby hindering its potential for commercial application in the field of thermoelectricity. A series of Al-doped CuInTe2 compounds were successfully prepared using solid-state reaction and spark plasma sintering techniques in this study. The influence of aluminum doping on the structure and thermoelectric performance was systematically investigated. Al doping remarkably enhances electrical transport performance by increasing carrier concentration. Meanwhile, Al doping induces substitutional point defects, dislocations, strain fluctuations, and nanoprecipitations of CuInAl4Te8, which act as additional barriers to phonon transport, leading to a reduction in the lattice thermal conductivity. Consequently, a minimum lattice thermal conductivity of 0.72 W/(m·K) at 823 K was obtained for CuIn0.8Al0.2Te2 sample, and a maximum ZT value of 0.88, an enhancement of 115% than pristine CuInTe2. The average ZT values at 323-823 K and 523-823 K were 0.34 and 0.60, respectively, representing approximately 127% and 122% compared with pristine CuInTe2. The remarkable enhancement of ZT and average ZT values for CuIn1-xAlxTe2 compounds demonstrates the efficacy of In-site doping in CuInTe2.

Keywords: CuInTe2; thermoelectric materials; doping; Seebeck coefficient

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本文引用格式

杨二阔, 张泽宇, 王亚松, 彭威, 历长云, 李广书, 康慧君, 王同敏. Al掺杂对CuInTe2热电性能的影响[J]. 金属学报, 2026, 62(6): 1137-1146 DOI:10.11900/0412.1961.2025.00269

YANG Erkuo, ZHANG Zeyu, WANG Yasong, PENG Wei, LI Changyun, LI Guangshu, KANG Huijun, WANG Tongmin. Influence of Al Doping on Thermoelectric Properties of CuInTe2[J]. Acta Metallurgica Sinica, 2026, 62(6): 1137-1146 DOI:10.11900/0412.1961.2025.00269

面对能源危机和环境保护这两大全球性挑战,热电科技作为环境友好型和可持续发展的清洁能源转换技术,是进一步提高能源效率的方法之一。热电材料具有将废热转化为电能的能力,因此在深空探测和低品位热能收集方面受到关注[1]。然而,热电材料因其低转换效率限制了其广泛应用。热电转换效率取决于热电材料的性能,其通过无量纲热电优值(ZT值)表示:

ZT=S2σT / κT

式中,SσTκT分别为Seebeck系数、电导率、热力学温度和总热导率(包括晶格热导率(κL)和电子热导率(κe))。S2σ也称为功率因子(PF),代表电输运性能。电导率与热导率通过载流子浓度相互耦合,因此,要获得较大的ZT值,就必须在PF和κT两者间取得最佳平衡。

CuInTe2,可以视为两个立方闪锌矿ZnTe结构堆叠,Cu、In原子交替取代Zn原子形成的短程无序、长程有序的晶体结构,从而获得比ZnTe更低的热导率,因此它被认为是一种有巨大潜力的P型热电材料。化学元素掺杂促进了CuInTe2的发展。已报道的掺杂元素如图1所示。掺杂金属元素,如Cu位Ag[2]、Ni[3,4]、Zn[5]掺杂或者本征空位调整,In位Cr[6]、Co[6]、Mg[7]、Ag[2,8]、Cd[9]、Hg[10]、Zn[5]、Mn[11,12]、Sb (半金属)[13]掺杂或者本征空位调整,通过这些元素掺杂可以调控能带结构或者载流子浓度,从而增强电输运性能。除了阳离子位调控外,阴离子位调控策略也用于增强热电性能。Te位S合金化[14]和本征空位调控可以引入强烈的点缺陷声子散射从而明显降低κL。Te位B、P元素掺杂可以调控载流子浓度提高Seebeck系数,从而提升CuInTe2的热电性能[15]。通过在CuInTe2中引入SnTe[16,17]、GeTe[16,18]、InTe[19]、In2Te3[20]、Zn (S/Se)[21]、石墨烯(graphene)[22]、AgSbTe2[23]等纳米级异质结或第二相也可调控电性能和热性能。此外,高压能够在调整能带结构的同时增大载流子浓度和迁移率,并且其引入的全尺寸缺陷结构可实现晶格热导率的明显下降[24]

图1

图1   元素周期表中CuInTe2的掺杂元素

Fig.1   Substitutions elements of CuInTe2 highlighted in periodic table


就成本、地壳自然储量而言,Al价格低廉且比上述其他掺杂元素储量丰富。就电负性而言,Al的电负性为1.61,小于掺杂剂Zn (1.65)、In (1.78)和Cu (1.9),但大于Mn (1.55)[25,26],因此,更容易占据阳离子位(Cu或In),而非阴离子位(Te)。CuIn1-xAlxTe2 (x = 0、0.2、0.4、0.6、0.8和1.0)在1170 K保温12 h合成条件下是均匀的固溶体[27],本工作与其区别在于1373 K保温24 h合成条件下合成的CuInTe2中有富Al相出现。本工作通过高温熔融、退火及等离子热压烧结工艺制备了Al掺杂的CuIn1-xAlxTe2化合物,并系统研究了Al掺杂量对微观结构和热电性能的影响,旨在通过热电性能的明显提升证实CuInTe2的In位掺杂有效性。

1 实验方法

1.1 CuIn1-xAlxTe2 的合成

CuIn1-xAlxTe2 (x = 0、0.01、0.03、0.1、0.2和0.3)热电材料通过高温熔融、退火及等离子热压烧结法制备。高纯单质Cu颗粒、In颗粒、Te颗粒和Al颗粒(纯度99.999%)作为实验原材料。根据化学计量比进行称量,将其均匀混合后用MRVS1003封管机真空密封(真空度< 10-3 Pa)至玻璃管中。将装有混合物的玻璃管放到X1700箱式马弗炉中进行高温反应合成,以10 K/min速率加热至1373 K保温24 h后水淬至室温,再在873 K下保温72 h进行退火。将热处理后的坯体在Pulverisette-4行星式球磨机中进行湿法球磨,经抽滤、真空干燥后得到粉体。将干燥后的粉末放入直径为13 mm的石墨模具中,再将其放入SPS-3T-H-G-18-MIN等离子热压烧结炉中进行加热加压处理。在烧结过程中,烧结压力为40~80 MPa,升温速率分别为96 K/min (< 753 K)和35 K/min (753~823 K),升温至823 K并保温5 min。所有样品的相对密度均大于95%。采用金刚石线切割机将烧结后的样品切成所需形状,用于测量热导率、Hall系数、Seebeck系数和电导率。

1.2 CuIn1-xAlxTe2 表征

采用Smartlab型X射线衍射仪(XRD,CuKα,波长0.15406 nm)分析确定合成粉末的物相,扫描速率5°/min,扫描范围5°~120°。采用Jade软件对XRD数据进行物相分析。采用JXA-8530F Plus电子探针(EPMA,电压15 kV)和IT800扫描电镜(SEM,电压15 kV)对精抛后的块体样品表面进行能谱(EDS)分析,检测掺杂元素的分布情况。为了探究CuInTe2中的纳米析出物,选择x = 0.2样品(以含第二相的x = 0.2样品为例),深入研究第二相对CuInTe2微观组织和晶体学的影响。采用双束聚焦离子束(FIB)技术制备透射样品。采用Talos F200x透射电子显微镜(TEM)表征块体样品的微观组织,采用选区电子衍射(SAED)技术表征物相结构。同时采用高分辨TEM (HRTEM)技术对纳米析出相及其与CuInTe2间的界面进行表征分析。

1.3 CuIn1-xAlxTe2 热电性能测试

采用LSR-3型电性能测试系统同步测量CuIn1-xAlxTe2样品的电导率和Seebeck系数。样品的总热导率通过κT = ρ0Dcp 计算,其中,D为热扩散系数,由LFA457激光导热仪测得;ρ0为样品的密度,采用Archimedes排水法测得;cp 为比热容,由Dulong-Petit公式计算而得。基于Van der Pauw法,采用8400 Hall测试仪测试CuInTe2热电材料的载流子浓度(n)和迁移率(μ)。

2 实验结果

2.1 CuIn1-xAlxTe2 的微观组织

所有CuIn1-xAlxTe2的衍射峰都匹配为四方CuInTe2相(空间群:I4¯2d,#122),当Al掺杂量超过0.1时,在约25.8°处可观察到第二相的微小衍射峰,如图2a所示。这表明Al在CuInTe2中的掺杂效率有限,当它超过CuInTe2的固溶极限时,会逐渐形成第二相。此外,对比局部峰的放大图(图2b)可知,掺杂后CuInTe2的(220)衍射峰向高角度偏移。其中,CuIn0.5Al0.5Te2 (220)峰的偏移角度最大,为0.13°。这主要归因于Al3+ (50 pm)和In3+ (81 pm)离子半径的差异。经对比峰位,初步判断该第二相为CuInAl4Te8相。上述XRD结果表明了CuIn1-xAlxTe2化合物的成功合成,并明确掺杂量超过固溶极限时出现第二相CuInAl4Te8

图2

图2   CuIn1-xAlxTe2 (x = 0、0.01、0.03、0.1、0.2、0.3和0.5)粉末在303 K的XRD谱和(220)峰放大图

Fig.2   XRD patterns of CuIn1-xAlxTe2 (x = 0, 0.01, 0.03, 0.1, 0.2, 0.3, and 0.5) powders at 303 K (a) and its enlargement of (220) peaks (b)


为了进一步确定Al元素在样品(x < 0.1)中的分布情况,采用SEM对样品进行表征,以不含第二相的x = 0.03样品为例进行典型性分析,结果如图3所示。在样品的横截面和纵截面上均观察到数个亚微米级孔隙;相应的EDS分析表明,除Cu、In和Te元素外,Al元素在样品中呈均匀分布。为确定Al掺杂后是否形成第二相,对x = 0.2样品进行SEM分析,结果如图4所示。元素面分布中的富Al相证明了富Al第二相的形成。

图3

图3   CuIn0.97Al0.03Te2样品纵截面和横截面的SEM像及EDS元素面分布图

Fig.3   SEM images and corresponding EDS element distribution mappings of longitudinal (a) and transverse (b) sections of CuIn0.97Al0.03Te2 sample


图4

图4   CuIn0.8Al0.2Te2样品的SEM像及EDS元素面分布图

Fig.4   Low (a) and high (b) magnified SEM images and corresponding EDS element distribution mappings of CuIn0.8Al0.2Te2 sample


x = 0.2样品中的纳米析出相及其与CuInTe2间的界面进行分析,结果如图5所示。图5a为样品的TEM像,图5b为纳米析出相CuInAl4Te8沿[112]晶带轴方向的(220)和(111)晶面的SAED花样(对应图5a中的右上方区域),图5c为CuInTe2沿[110]晶带轴方向的(112)和(112)晶面的SAED花样(对应图5a中的左下方区域)。CuInTe2和纳米析出相之间的相界如图5d所示(图5a中A区放大图)。图5e图5d中C区放大图,对图5e中D区域进行逆快速Fourier变换(IFFT)处理,结果如图5f所示。在图中可清晰地观察到若干位错,这主要与相界面处原子错排密切相关。为进一步探究位错周围的应变状态,对图5f进行了几何相位分析(GPA),图5g~i为不同方向的应变剖面图。图5j图5a中B区的HRTEM像,可观察到CuInTe2和界面过渡层,从而明确了相界位置。对图5j中E区进行快速Fourier变换(FFT),结果如图5k所示,经分析其为四方结构的CuInTe2。对图5j中E区进行IFFT处理,结果如图5l所示,表明CuInTe2与第二相之间存在共格关系。图5m~o图5l不同方向的应变剖面图,可观察到明显的应变分布。这些点缺陷、位错和纳米析出相,协同增强了声子散射,促使晶格热导率降低[1,7,13,19,21]

图5

图5   纳米析出相及其与CuInTe2间界面的TEM表征

Fig.5   TEM characteristics of nanoprecipitate phases and interface between nanoprecipitate phase and the matrix

(a) TEM image

(b, c) SAED patterns of upper right corner (b) and bottom left corner (c) of Fig.5a

(d) enlarged TEM image corresponding to the rectangle area A in Fig.5a

(e) HRTEM image corresponding to the rectangle area C in Fig.5d

(f) inverse fast Fourier transform (IFFT) of the rectangle area D in Fig.5e

(g-i) geometric phase analyses (GPA) of εxx (g), εyy (h), and εxy (i) for Fig.5f (εxxnormal strain along the x-axis, εyy —normal strain along the y-axis, εxy —shear strain along the xy-axis)

(j) HRTEM image corresponding to the rectangle area B in Fig.5a

(k) fast Fourier transform (FFT) of the rectangle area E in Fig.5j

(l) IFFT of the rectangle area E in Fig.5j

(m-o) GPA of εxx (m), εyy (n), and εxy (o) for Fig.5l


2.2 CuIn1-xAlxTe2 的热电输运性能

CuIn1-xAlxTe2 (x = 0、0.01、0.03、0.1、0.2和0.3)样品随温度变化的电输运性能曲线如图6所示。电导率均表现出随温度变化的相似行为,在303~723 K之间时,掺杂样品的电导率随温度升高而增加,显示出典型的本征半导体行为。然而,随温度继续升高,电导率增幅逐渐趋缓并趋于稳定,在高温区域甚至出现微弱下降趋势,这种现象在其他类金刚石化合物(如AgGaTe2[28]和CuGaTe2[29])中更明显,且转变温度点(723 K,如图6a所示)要比AgGaTe2和AgInTe2 (约100 K)高[30]。在303 K时,纯CuInTe2的电导率为3.1 S/cm。随Al掺杂量逐渐增加,CuIn1-xAlxTe2系列样品的电导率显著增加。303 K时CuIn0.7Al0.3Te2的电导率提升至24 S/cm,相比纯CuInTe2增幅达674%。这主要由增大的载流子浓度所致,如图6c所示。随着温度的升高,在473 K以下温度范围,CuIn1-xAlxTe2电导率缓慢增加,在473 K以上温度范围则快速增加,这种急剧变化趋势也见于其他文献报道中[2,14,15,21,23,24,31~35]。在823 K时,CuIn0.7Al0.3Te2的最大电导率为232.1 S/cm,比纯CuInTe2增加101%。Seebeck系数与电导率呈现相反变化趋势,这也是由于增大的载流子浓度所致。如图6b所示,在303 K时,纯CuInTe2的Seebeck系数为329.2 μV/K,而CuIn0.7Al0.3Te2的Seebeck系数降至210.7 μV/K,比纯CuInTe2下降了56%。这主要归因于CuInAl4Te8第二相中的空位浓度比基体CuInTe2大,如图6c所示。第二相的析出(图245)消耗了掺杂的Al原子,同时生成的CuInAl4Te8第二相提供的空位数量增多,进而导致空位浓度逐渐上升。同时,第二相的形成增强了载流子散射,致使载流子迁移率降低。在823 K时,CuIn1-xAlxTe2 (x = 0、0.01、0.03、0.1、0.2和0.3)样品的Seebeck系数稳定在185~200 μV/K。如图6d所示,在823 K时,CuIn1-xAlxTe2样品显著增大的电导率与适度降低的Seebeck系数的协同作用提升了功率因子,进而有效改善了材料的电传输性能。CuIn1-xAlxTe2的功率因子远高于AgGaTe2和AgInTe2[30]。如图6d所示,在303 K时,CuIn0.7Al0.3Te2样品的功率因子比纯CuInTe2提高了267%;在823 K时,CuIn0.7Al0.3Te2样品的功率因子比纯CuInTe2提高了75%,这有利于提升CuIn0.7Al0.3Te2样品的热电性能。

图6

图6   CuIn1-xAlxTe2 (x = 0、0.01、0.03、0.1、0.2和0.3)化合物的电输运性能

Fig.6   Electrical transport properties of CuIn1-xAlxTe2 (x = 0, 0.01, 0.03, 0.1, 0.2, and 0.3)

(a) temperature (T) dependent electrical conductivity (σ)

(b) temperature dependent Seebeck coefficient (S)

(c) doped‐content dependent carrier concentration (n) and mobility (μ)

(d) temperature dependent power factor (PF)


CuIn1-xAlxTe2 (x = 0、0.01、0.03、0.1、0.2和0.3)化合物随温度变化的总热导率曲线如图7a所示。在303 K时,纯CuInTe2的总热导率为3.95 W/(m·K),该数值与文献报道[5,15,21,31,32]相当。在该温度下的Al掺杂样品中,随掺杂量增加,CuIn1-xAlxTe2 (x < 0.1)的总热导率逐渐降低,而CuIn1-xAlxTe2 (x > 0.1)的总热导率开始升高;CuIn0.8Al0.2Te2样品获得最低总热导率,为2.79 W/(m·K),比纯CuInTe2降低了29%;CuIn0.7-Al0.3Te2样品的总热导率最大,这归因于CuInAl4Te8纳米析出相含量增多以及晶粒增大[13,18]。随着温度的升高,所有样品的总热导率均呈现下降趋势。在823 K时,CuIn0.8Al0.2Te2样品获得最小总热导率,为0.72 W/(m·K)。增加的空位浓度导致电子热导率增加,如图7b所示。根据Wiedemann-Franz关系,晶格热导率由总热导率减去电子热导率确定。由于电子热导率较低,晶格热导率主导总热导率。如图7c所示,在303 K时,掺杂Al后CuIn1-xAlxTe2的晶格热导率显著降低,这表明Al掺杂的声子-声子的Umklapp散射和第二相增强的声子散射是导致热导率下降的主要机制。在303 K时,CuIn0.8Al0.2Te2样品的晶格热导率最小,为2.78 W/(m·K)。随着温度的升高,所有样品的晶格热导率都逐步下降,在823 K时,CuIn0.8Al0.2Te2样品的晶格热导率达到最小,为0.54 W/(m·K),如图7d所示,均低于其他热电材料,如β-FeSi2[36]、高熵Ti0.57Zr0.4Al0.02Ta0.01NiSn0.98Sb0.02[37]、MnSi1.74[38]、SmMg2Sb2[39]、(PbTe)0.97(Ag2Te)0.03[40]、Sn0.93-Mn0.1Te[41]、Pb0.991Ag0.003Te[42]以及GaGeTe[43]等。与采用不同优化策略的相似体系对比,在823 K时,CuIn0.8Al0.2Te2样品的晶格热导率(0.54 W/(m·K))仍低于大多数的CuInTe2基热电材料,如CuInTe2 + 0.5%SnO2[32]、CuInTe2 + 9%ZnS/Se[21]、CuInTe2 + 7 SnTe[16]及(CuInTe2)1.85(In2Te3)0.15[20]等。

图7

图7   CuIn1-xAlxTe2 (x = 0、0.01、0.03、0.1、0.2和0.3)化合物的热运输性能及与其他热电材料[16,20,21,30,36,40~45]的对比

Fig.7   Thermal transport properties of CuIn1-xAlxTe2 (x = 0, 0.01, 0.03, 0.1, 0.2, and 0.3)

(a) total thermal conductivity (κT)

(b) electrical thermal conductivity (κe)

(c) lattice thermal conductivity (κL)

(d) comparation of the lattice thermal conductivity with other system[16,20,21,30,36,40-45]


采用Debye-Callaway模型(式(2))揭示Al掺杂对CuIn1-xAlxTe2材料晶格热导率的影响,声子的散射参数(τC)计算公式为:

τC=τB+τD+τU+τR+

式中,τB为晶界散射机制贡献,τD为点缺陷散射机制贡献,τU为声子-声子的Umklapp散射机制贡献,τR为声子共振散射机制贡献,τBτDτU被认为是重要的散射机制。Debye-Callaway模型的总散射参数(Γtot)主要取决于应变场波动(ΓS)和质量场波动(ΓM)[8]。随温度升高CuIn1-xAlxTe2的晶格热导率降低表明,声子-声子的Umklapp散射过程是主要的声子散射机制。如表1所示,随着Al掺杂量的增加,Γtot也在增加,这与图7中晶格热导率的减小情况一致。ΓS主导CuIn1-xAlxTe2 (x = 0.01、0.03、0.1)晶格热导率的减小,但随着Al掺杂含量的进一步增加,ΓM主导了CuIn1-xAlxTe2 (x = 0.2、0.3)晶格热导率的减小,与CuIn1-x SbxTe2化合物中ΓS主导晶格热导率减小的波动趋势不同[13]。这一现象归因于掺杂的Al原子和In原子之间的质量和半径差异。

表1   CuIn1-xAlxTe2 (x = 0.01、0.03、0.1、0.2和0.3)的质量场波动、应变场波动和总散射参数

Table 1  Mass field fluctuation (ΓM), strain field fluctuation (ΓS), and total scattering parameter (Γtot) of CuIn1-xAlxTe2 (x = 0.01, 0.03, 0.1, 0.2, and 0.3)

xΓM / 10-3ΓS / 10-3Γtot / 10-3
0.015.99.815.7
0.0317.828.045.8
0.161.878.6140.3
0.2130.5120.1250.6
0.3207.0132.9339.9

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2.3 CuIn1-xAlxTe2 的热电优值

CuIn1-xAlxTe2 (x = 0、0.01、0.03、0.1、0.2和0.3)化合物随温度变化的ZT值曲线如图8所示。在303 K时,由于增大的功率因子和减小的热导率,Al掺杂样品的ZT值随掺杂量增加而先增加后逐渐降低,CuIn0.8Al0.2Te2样品获得最大ZT值(0.014)。CuIn1-xAlxTe2ZT值随着温度的上升而增大,尤其在423 K以上,CuIn1-xAlxTe2ZT值因温度的上升呈现显著的快速增长趋势。在823 K时,CuIn0.8Al0.2Te2样品的ZT值达到峰值,为0.88,比CuInTe2提高了115%。这一ZT值(0.88)与文献报道的同类材料性能相当:在854 K时CuIn1-xMnxTe2ZT值为0.82[34],在813 K时CuIn1-xMnxTe2ZT值为0.80[11],在820 K时Cu0.96InTe2ZT值为0.83[44],在737 K时Cu1-x In1-x Zn2x Te2ZT值为0.67[5],以及在675 K时Cu1-x NixInTe2ZT值为0.35[3]。鉴于热电材料的平均ZT值对实际应用非常重要,本工作计算了303~823和573~823 K之间的平均ZT值(ZTavg(303-823 K)ZTavg(573-823 K)),以评估CuIn1-xAlxTe2 (x = 0、0.01、0.03、0.1、0.2和0.3)的热电性能。如图8b所示,在303~823和573~823 K范围,Al掺杂显著提升了CuIn1-xAlxTe2在上述温度区间内的平均ZT值。在303~823 K范围,所有掺杂Al样品CuIn1-xAlxTe2的平均ZT值超过0.21,比纯CuInTe2 (0.15)增加了40%,CuIn0.8Al0.2Te2样品的平均ZT值比纯CuInTe2提高了127%。在573~823 K范围,CuIn0.8Al0.2Te2样品的平均ZT值达到了0.60,比纯CuInTe2 (0.27)提高了122%。

图8

图8   CuIn1-xAlxTe2 (x = 0、0.01、0.03、0.1、0.2和0.3)化合物的热电优值

Fig.8   Thermoelectric figure of merit (ZT) values of CuIn1-xAlxTe2 (x = 0, 0.01, 0.03, 0.1, 0.2, and 0.3)

(a) temperature dependent ZT value

(b) average ZT value from 303 K to 823 K and from 573 to 823 K (ZTavg(303-823 K) and ZTavg(573-823 K))


综合Sb[13]、Al元素单一同价掺杂对CuInTe2性能改善的实验结果,以及相关文献报道[2,5,11],单纯在阳离子In位进行同价掺杂对提升CuInTe2黄铜矿体系性能的效果有限。基于载流子浓度调控与热导率优化的需求,在阳离子位点采用多元掺杂策略[7,17,18,45],有望进一步提升该体系的热电性能。

3 结论

(1) 掺Al量较低的CuInTe2是均匀的固溶体,当Al掺杂量超过固溶极限时,会析出CuInAl4Te8相。同时,Al掺杂导致CuInTe2微观组织中存在大量位错,引发明显的应变波动。

(2) 在823 K时,CuIn0.8Al0.2Te2样品的晶格热导率达到最小值,0.54 W/(m·K)。这归因于Al掺杂引入的点缺陷、位错和CuInAl4Te8纳米析出相增强了中高频声子散射,从而实现了晶格热导率的降低。

(3) CuIn0.8Al0.2Te2在823 K时的ZT值为0.88,在303~823 K之间的平均ZT值为0.34,在573~823 K之间的平均ZT值为0.60,比纯CuInTe2提高了122%。In位同价掺杂Al可以在CuInTe2中引入更多的缺陷,增强了声子散射,降低了晶格热导率,从而提升CuInTe2的热电性能。

参考文献

Qin Y X, Qin B C, Hong T, et al.

Grid-plainification enables medium-temperature PbSe thermoelectrics to cool better than Bi2Te3

[J]. Science, 2024, 383: 1204

DOI      URL     [本文引用: 2]

\n Thermoelectric cooling technology has important applications for processes such as precise temperature control in intelligent electronics. The bismuth telluride (Bi\n 2\n Te\n 3\n )–based coolers currently in use are limited by the scarcity of Te and less-than-ideal cooling capability. We demonstrate how removing lattice vacancies through a grid-design strategy switched PbSe from being useful as a medium-temperature power generator to a thermoelectric cooler. At room temperature, the seven-pair device based on n-type PbSe and p-type SnSe produced a maximum cooling temperature difference of ~73 kelvin, with a single-leg power generation efficiency approaching 11.2%. We attribute our results to a power factor of >52 microwatts per centimeter per square kelvin, which was achieved by boosting carrier mobility. Our demonstration suggests a path for commercial applications of thermoelectric cooling based on Earth-abundant Te-free selenide-based compounds.\n

Wang C Y, Ma Q Y, Xue H R, et al.

Tetrahedral distortion and thermoelectric performance of the Ag-substituted CuInTe2 chalcopyrite compound

[J]. ACS Appl. Energy Mater., 2020, 3: 11015

DOI      URL     [本文引用: 4]

Kucek V, Drasar C, Navratil J, et al.

Thermoelectric properties of Ni-doped CuInTe2

[J]. J. Phys. Chem. Solids, 2015, 83: 18

DOI      URL     [本文引用: 2]

Sadia Y, Lifshitz I, Sebaoun D, et al.

Transport properties of Cd- and Ni-doped CuIn(S,Se,Te)2-based semiconductors

[J]. ACS Appl. Electron. Mater, 2024, 6: 2870

DOI      URL     [本文引用: 1]

Yang J F, Chen S P, Du Z L, et al.

Lattice defects and thermoelectric properties: The case of p-type CuInTe2 chalcopyrite on introduction of zinc

[J]. Dalton Trans., 2014, 43: 15228

DOI      URL     [本文引用: 5]

Luo Y B.

Investigation on the chalcopyrite CuInTe2 based thermoelectric materials

[D]. Wuhan: Huazhong University of Science and Technology, 2016

[本文引用: 2]

罗裕波.

黄铜矿结构CuInTe2基热电材料研究

[D]. 武汉: 华中科技大学, 2016

[本文引用: 2]

Xiong Q H, Wu H, Zhang K Q, et al.

Realizing high thermoelectric performance and thermal stability in CuInTe2 through heavy dose Mg doping

[J]. Acta Mater., 2024, 278: 120268

DOI      URL     [本文引用: 3]

Yang E K, Jiang Q W, Li G S, et al.

Enhancing thermoelectric performance of CuInTe2 via trace Ag doping at indium sites

[J]. ACS Appl. Mater. Interfaces, 2023, 15: 49370

DOI      URL     [本文引用: 2]

Cheng N, Liu R, Bai S, et al.

Enhanced thermoelectric performance in Cd doped CuInTe2 compounds

[J]. J. Appl. Phys., 2014, 115: 163705

DOI      URL     [本文引用: 1]

CuIn1−xCdxTe2 materials (x = 0, 0.02, 0.05, and 0.1) are prepared using melting-annealing method and the highly densified bulk samples are obtained through Spark Plasma Sintering. The X-ray diffraction data confirm that nearly pure chalcopyrite structures are obtained in all the samples. Due to the substitution of Cd at In sites, the carrier concentration is greatly increased, leading to much enhanced electrical conductivity and power factor. The single parabolic band model is used to describe the electrical transport properties of CuInTe2 and the low temperature Hall mobility is also modeled. By combing theoretical model and experiment data, the optimum carrier concentration in CuInTe2 is proposed to explain the greatly enhanced power factors in the Cd doped CuInTe2. In addition, the thermal conductivity is reduced by extra phonon scattering due to the atomic mass and radius fluctuations between Cd and In atoms. The maximum zTs are observed in CuIn0.98Cd0.02Te2 and CuIn0.9Cd0.1Te2 samples, which are improved by over 100% at room temperature and around 20% at 600 K.

Kucek V, Drasar C, Kasparova J, et al.

High-temperature thermoelectric properties of Hg-doped CuInTe2

[J]. J. Appl. Phys., 2015, 118: 125105

DOI      URL     [本文引用: 1]

Polycrystalline samples of composition CuIn1−xHgxTe2 (x = 0–0.21) were synthesized from elements of 5N purity using a solid state reaction. The phase purity of the products was verified by X-ray diffraction. Samples for transport property measurements were prepared using hot-pressing. The samples were characterized by measurement of the electrical conductivity, Hall coefficient, Seebeck coefficient, and thermal conductivity over a temperature range of 300–675 K. All samples show p-type conductivity. We discuss the influence of Hg substitution on the free carrier concentration and thermoelectric performance. The investigation of the thermoelectric properties shows up to a 40% improvement of ZT in the temperature range of 300–600 K.

Luo P F, You L, Yang J, et al.

Effects of Mn substitution on thermoelectric properties of CuIn1-xMnxTe2

[J]. Chin. Phys., 2017, 26B: 097201

[本文引用: 3]

Wang H X, Ying P Z, Yang J F, et al.

Defects and thermoelectric performance of ternary chalcopyrite CuInTe2-based semiconductors doped with Mn

[J]. Acta Phys. Sin., 2016, 65: 067201

[本文引用: 1]

王鸿翔, 应鹏展, 杨江锋 .

Mn掺杂后三元黄铜矿结构半导体CuInTe2的缺陷特征与热电性能

[J]. 物理学报, 2016, 65: 067201

[本文引用: 1]

Yang E K, Yu L F, Li G S, et al.

Second phases and dislocations to boost the thermoelectric properties of CuInTe2 by Sb doping at in site

[J]. Chem. Mater., 2024, 36: 8753

[本文引用: 5]

Qin Y T, Qiu P F, Shi X, et al.

Thermoelectric properties for CuInTe2-xSx (x = 0, 0.05, 0.1, 0.15) solid solution

[J]. J. Inorg. Mater, 2017, 32: 1171

DOI      URL     [本文引用: 2]

覃玉婷, 仇鹏飞, 史 迅 .

CuInTe2-xSx (x = 0, 0.05, 0.1, 0.15)固溶体的热电性能

[J]. 无机材料学报, 2017, 32: 1171

DOI      [本文引用: 2]

类金刚石结构化合物CuInTe2作为一种新型的热电材料引起了广泛关注。CuInTe2在中低温度段热导偏大, 限制了其热电性能的提高。本研究合成了CuInTe2-xSx(x=0, 0.05, 0.1, 0.15)固溶体, XRD和SEM-EDS结果表明所得固溶体均为元素分布均匀的单一物相。同时还发现S和Te元素的固溶有效地引入了点缺陷散射, 降低了晶格热导率。通过Callaway模型模拟实验数据发现应力场涨落引起的声子散射是其晶格热导率降低的主要原因, 但Te位固溶S引起了电输运性能的降低, 若能采用掺杂等方式改善电性能, 则其热电性能有望得到进一步优化。

Luo Y B, Yang J Y, Jiang Q H, et al.

Progressive regulation of electrical and thermal transport properties to high-performance CuInTe2 thermoelectric materials

[J]. Adv. Energy Mater., 2016, 6: 1600007

DOI      URL     [本文引用: 3]

Zhou Y M, Wu H J, Pei Y L, et al.

Strategy to optimize the overall thermoelectric properties of SnTe via compositing with its property-counter CuInTe2

[J]. Acta Mater., 2017, 125: 542

DOI      URL     [本文引用: 5]

Hwang J, Lee M, Yu B K, et al.

Enhancement of thermoelectric performance in a non-toxic CuInTe2/SnTe coated grain nanocomposite

[J]. J. Mater. Chem., 2021, 9A: 14851

[本文引用: 2]

Kim H, Kihoi S K, Shenoy U S, et al.

High thermoelectric and mechanical performance achieved by a hyperconverged electronic structure and low lattice thermal conductivity in GeTe through CuInTe2 alloying

[J]. J. Mater. Chem., 2023, 11A: 8119

[本文引用: 3]

Huang R C, Huang Y, Zhu B, et al.

Large enhancement of thermoelectric performance of InTe compound by sintering and CuInTe2 doping

[J]. J. Appl. Phys., 2019, 126: 125108

DOI      URL     [本文引用: 2]

InTe is a newly emerging thermoelectric material working at a middle temperature range with an ultralow thermal conductivity. Nevertheless, the figure of merit (ZT) of InTe currently is way too inappreciable compared with other material systems. In this work, we present that a peak ZT as high as ∼0.8 is achieved at 723 K in InTe composited with 1.02% of CuInTe2 prepared by spark plasma sintering. The large improvement of thermoelectric performance in sintered InTe mainly comes from the enhancement of conductivity. The reasons for this phenomenon are investigated as well. We find that extra In vacancies which lead to an increment of hole concentration and the energy barrier at grain boundaries are responsible for the behavior of electrical properties. Besides, a small amount of CuInTe2 also contributes to the improvement of power factor, which leads to higher ZT.

Yan Y C, Lu X, Wang G Y, et al.

ZT = 1.1 in CuInTe2 solid solutions enabled by rational defect engineering

[J]. ACS Appl. Energy Mater., 2020, 3: 2039

DOI      URL     [本文引用: 4]

Luo Y B, Jiang Q H, Yang J Y, et al.

Simultaneous regulation of electrical and thermal transport properties in CuInTe2 by directly incorporating excess ZnX (X = S, Se)

[J]. Nano Energy, 2017, 32: 80

DOI      URL     [本文引用: 7]

Chen H J, Yang C Y, Liu H L, et al.

Thermoelectric properties of CuInTe2/graphene composites

[J]. CrystEngComm, 2013, 15: 6648

DOI      URL     [本文引用: 1]

Xiong Q H, Yan Y C, Li N H, et al.

Strong anharmonicity induced low lattice thermal conductivity and high thermoelectric performance in (CuInTe2)1-x (AgSbTe2)x system

[J]. Appl. Phys. Lett., 2022, 121: 013903

[本文引用: 2]

Wang Y Q, Zhang H, Wu Y, et al.

Dual-optimization of transport properties enabled by high-pressure treatments for CuInTe2 thermoelectric materials

[J]. Chem. Eng. J., 2024, 490: 151588

DOI      URL     [本文引用: 2]

Wang W, Liu S X, Wang Y, et al.

Tailoring local chemical fluctuation of high-entropy structures in thermoelectric materials

[J]. Sci. Adv., 2024, 10: eadp4372

DOI      URL     [本文引用: 1]

In high-entropy materials, local chemical fluctuation from multiple elements inhabiting the same crystallographic site plays a crucial role in their unique properties. Using atomic-resolution chemical mapping, we identified the respective contributions of different element characteristics on the local chemical fluctuation of high-entropy structures in thermoelectric materials. Electronegativity and mass had a comparable influence on the fluctuations of constituent elements, while the radius made a slight contribution. The local chemical fluctuation was further tailored by selecting specific elements to induce large lattice distortion and strong strain fluctuation to lower lattice thermal conductivity independent of increased entropy. The chemical bond fluctuation induced by the electronegativity difference had a noticeable contribution to the composition-dependent lattice thermal conductivity in addition to the known fluctuations of mass and strain field. Our findings provide a fundamental principle for tuning local chemical fluctuation and lattice thermal conductivity in high-entropy thermoelectric materials.

Nolas G S, Sharp J, Goldsmid H J.

The phonon-glass electron-crystal approach to thermoelectric materials research

[A]. Thermoelectrics: Basic Principles and New Materials Developments[M]. Berlin: Springer, 2001: 177

[本文引用: 1]

Seon S, Kim B, Park O, et al.

Significant reduction of lattice thermal conductivity observed in CuInTe2-CuAlTe2 solid-solution alloys

[J]. Phys. Chem. Chem. Phys., 2024, 26: 28858

DOI      URL     [本文引用: 1]

The electrical, thermal, and thermoelectric properties of CuInTe2–CuAlTe2 solid solutions were investigated. The power factors decreased due to reduced carrier mobility, while lattice thermal conductivity dropped significantly.

Cao Y, Su X L, Meng F C, et al.

Origin of the distinct thermoelectric transport properties of chalcopyrite ABTe2 (A = Cu, Ag; B = Ga, In)

[J]. Adv. Funct. Mater., 2020, 30: 2005861

DOI      URL     [本文引用: 1]

Su X L, Zhao N, Hao S Q, et al.

High thermoelectric performance in the wide band-gap AgGa1-xTe2 compounds: Directional negative thermal expansion and intrinsically low thermal conductivity

[J]. Adv. Funct. Mater., 2019, 29: 1806534

DOI      URL     [本文引用: 1]

Plirdpring T, Kurosaki K, Kosuga A, et al.

Chalcopyrite CuGaTe2: A high-efficiency bulk thermoelectric material

[J]. Adv. Mater., 2012, 24: 3622

DOI      URL     [本文引用: 4]

Zhou G, Wang D.

High thermoelectric performance from optimization of hole-doped CuInTe2

[J]. Phys. Chem. Chem. Phys., 2016, 18: 5925

DOI      PMID      [本文引用: 2]

We investigated the electronic structure, lattice dynamics and thermoelectric transport properties of CuInTe2 based on first-principles calculations. From the analysis of density of states and partial charge density, it can be expected that p-doping at the In-site or n-doping at the Cu-site will barely modify the electronic states near the valence or conduction band edge but increase the carrier concentration to achieve the highest thermoelectric efficiency. Lattice dynamics calculations suggest that the thermal conductivity of CuInTe2 can be effectively reduced by introducing structural defects at Cu, In and Te sites. p-type CuInTe2 possesses better thermoelectric properties as compared to the n-type one, which mainly originates from the steeper density of states resulting from nearly degenerate valence bands near the band edge. The temperature dependence of the thermoelectric transport properties of p-type CuInTe2 at different carrier concentrations was studied in detail, which is found to be in good agreement with the experimental data. Our results of calculation showed that p-type CuInTe2 can achieve an upper-limit figure of merit value of 1.72 at 850 K and are promising thermoelectric materials for waste heat recovery at medium temperatures.

Li W X, Luo Y B, Zheng Y, et al.

Enhancement of the thermoelectric performance of CuInTe2 via SnO2 in situ replacement

[J]. J. Mater. Sci. Mater. Electron, 2018, 29: 4732

DOI      URL     [本文引用: 2]

Kim H, Kihoi S K, Lee H S.

Point defects control in non-stoichiometric CuInTe2 compounds and its corresponding effects on the microstructure and thermoelectric properties

[J]. J. Alloys Compd., 2021, 869: 159381

DOI      URL    

Ahmed F, Tsujii N, Matsushita Y, et al.

Influence of slight substitution (Mn/In) on thermoelectric and magnetic properties in chalcopyrite-type CuInTe2

[J]. J. Electron. Mater., 2019, 48: 4524

DOI      [本文引用: 1]

Luo Y B, Yang J Y, Jiang Q H, et al.

Large enhancement of thermoelectric performance of CuInTe2 via a synergistic strategy of point defects and microstructure engineering

[J]. Nano Energy, 2015, 18: 37

DOI      URL     [本文引用: 1]

Cheng J, Gan L, Zhang J W, et al.

Thermoelectric properties of heavily co-doped β-FeSi2

[J]. J. Mater. Sci. Technol., 2024, 187: 248

DOI      URL     [本文引用: 3]

Zhang X L, Huang M, Li H J, et al.

Ultralow lattice thermal conductivity and improved thermoelectric performance in a Hf-free half-Heusler compound modulated by entropy engineering

[J]. J. Mater. Chem., 2023, 11A: 8150

[本文引用: 1]

Chauhan N S, Sara S G, Bhattacharya A, et al.

Odd-stoichiometry and secondary phase relations in higher manganese silicides

[J]. Adv. Funct. Mater., 2024, 34: 2313948

DOI      URL     [本文引用: 1]

Zhang Z W, Li J, Yao H H, et al.

Identifying the promising n-type SmMg2Sb2-based Zintl phase thermoelectric material

[J]. Acta Mater., 2024, 268: 119777

DOI      URL     [本文引用: 1]

Yu Y, Sheskin A, Wang Z Y, et al.

Ostwald ripening of Ag2Te precipitates in thermoelectric PbTe: Effects of crystallography, dislocations, and interatomic bonding

[J]. Adv. Energy Mater., 2024, 14: 2304442

DOI      URL     [本文引用: 3]

Yang H J, Wu L Q, Feng X B, et al.

Optimization of mechanical and thermoelectric properties of SnTe-based semiconductors by Mn alloying modulated precipitation evolution

[J]. Small, 2024, 20: 2310692

DOI      URL     [本文引用: 1]

Liu S B, Qin Y X, Wen Y, et al.

Efforts toward the fabrication of thermoelectric cooling module based on n-type and p-type PbTe ingots

[J]. Adv. Funct. Mater., 2024, 34: 2315707

DOI      URL     [本文引用: 1]

Zhou H, Cheng K, Meng X, et al.

Layer-structured GaGeTe compound as a promising thermoelectric material

[J]. ACS Appl. Energy Mater., 2023, 6: 4264

DOI      URL     [本文引用: 1]

Xia Z Z L, Wang G W, Zhou X Y, et al.

Effect of the Cu vacancy on the thermoelectric performance of p-type Cu1-xInTe2 compounds

[J]. Ceram. Int., 2017, 43: 16276

DOI      URL     [本文引用: 1]

Cai J F, Yang J X, Liu G Q, et al.

Ultralow thermal conductivity and improved ZT of CuInTe2 by high-entropy structure design

[J]. Mater. Today Phys., 2021, 18: 100394

[本文引用: 3]

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