Thermoelectric properties of Cu doped ZnSb containing Zn3P2 particles

Abstract

We prepared ZnSb containing Zn3P2 particles of size ranging from a few tens to several hundred nanometers by melting powders of Zn, Sb, and P. Materials with Zn3P2 content up to 3.75% were made and subsequently ball-milled and hot pressed. A reduction in the thermal conductivity of 15% was achieved. By adding 0.2% Cu the carrier concentration increased an order of magnitude, to 2.0 × 1019 cm−3, while the mobility remained unaffected. The resulting increase in electrical conductivity together with the reduced thermal conductivity, led to a significant increase in the dimensionless figure of merit, in excess of 0.9 around 550 K.

Review of Research on the Thermoelectric Material ZnSb

“…Here, Cd is not expected to act as an acceptor, but for increasing the phonon scattering and thereby reducing the thermal conductivity. A similar intended function has been applied by adding P to increase alloy phonon scattering in the Cu doped ZnSb [18,69].…”

Enhancement of thermoelectric properties by energy filtering: Theoretical potential and experimental reality in nanostructured ZnSb

“…33,[35][36][37] This has led to an improvement of the figure-of-merit from 0.3 in the 1960s 38 to consistent reports of zT > 0:9. 22,23,27 A number of theoretical studies of ZnSb have been reported in recent years. Ab initio band structure calculations have been reported by several groups.…”

“…Further, the thermoelectric properties of bulk ZnSb are suitable for improvement by nanostructuring. 24,25 Several reports on densely packed pellets of ZnSb have appeared recently, utilizing techniques like ball-milling, [26][27][28][29][30] spark plasma sintering, 31 and cryogenic milling. 32 Optimization of doping levels and alloying elements have significantly enhanced the thermoelectric properties of ZnSb, 22,27,33,34 0021-8979/2016/119(12)/125103/10/$30.00…”

Оптимальный рабочий диапазон температур и оценка срока службы термоэлектрика ZnSb:0.1 ат% Cu

“…Исследование природы этих процессов в зависимости от вида ле-гирующей примеси, состава добавки и температуры представляет актуальную задачу, поскольку позволяет определять наиболее перспективные для практического применения составы с оценкой реальных изменений свойств материала, происходящих при его использо-вании в различных диапазонах температур. В данной работе объектом исследования служит образец ZnSb с 0.1 ат% сверхстехиометрической меди, входящий в число наиболее эффективных составов легированно-го антимонида цинка [2][3][4][5][6]. Величина термоэлектриче-ской эффективности данного материала, приготовлен-ного горячим прессованием с последующими отжи-гом и закалкой, достигает значений ZT ≈ 0.9−1.1 при 550−700 K [7].…”