Phase-engineered high-entropy metastable FCC Cu2- y Ag y (In x Sn1- x )Se2S nanomaterials with high thermoelectric performance

Wanjia Zhang; Yue Lou; Hongliang Dong; Fanshi Wu; Janak Tiwari; Zhan Shi; Tianli Feng; Sokrates T Pantelides; Biao Xu

doi:10.1039/d2sc02915d

Phase-engineered high-entropy metastable FCC Cu_{2- y} Ag _y (In _x Sn_{1- x} )Se₂S nanomaterials with high thermoelectric performance

Chem Sci. 2022 Aug 24;13(35):10461-10471. doi: 10.1039/d2sc02915d. eCollection 2022 Sep 14.

Authors

Wanjia Zhang¹, Yue Lou¹, Hongliang Dong², Fanshi Wu¹, Janak Tiwari³, Zhan Shi⁴, Tianli Feng³, Sokrates T Pantelides⁵, Biao Xu¹

Affiliations

¹ Department of Chemistry and Chemical Engineering, Nanjing University of Science and Technology Nanjing Jiangsu 210094 P. R. China louyue@njust.edu.cn xubiao@njust.edu.cn.
² Center for High Pressure Science and Technology Advanced Research Shanghai 201203 China.
³ Department of Mechanical Engineering, The University of Utah Salt Lake City UT 84112 USA.
⁴ State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, College of Chemistry, Jilin University Changchun 130012 P. R. China.
⁵ Department of Physics and Astronomy and Department of Electrical and Computer Engineering, Vanderbilt University Nashville TN 37235 USA.

Abstract

Crystal-phase engineering to create metastable polymorphs is an effective and powerful way to modulate the physicochemical properties and functions of semiconductor materials, but it has been rarely explored in thermoelectrics due to concerns over thermal stability. Herein, we develop a combined colloidal synthesis and sintering route to prepare nanostructured solids through ligand retention. Nano-scale control over the unconventional cubic-phase is realized in a high-entropy Cu_2-y Ag _y (In _x Sn_1-x )Se₂S (x = 0-0.25, y = 0, 0.07, 0.13) system by surface-ligand protection and size-driven phase stabilization. Different from the common monoclinic phase, the unconventional cubic-phase samples can optimize electrical and thermal properties through phase and entropy design. A high power factor (0.44 mW m^-1 K^-2), an ultralow thermal conductivity (0.25 W m^-1 K^-1) and a ZT value of 1.52 are achieved at 873 K for the cubic Cu_1.87Ag_0.13(In_0.06Sn_0.94)Se₂S nanostructured sample. This study highlights a new method for the synthesis of metastable phase high-entropy materials and gives insights into stabilizing the metastable phase through ligand retention in other research communities.