Programme

O.27 -- Oral, VCTP-50

Date: Thursday, 7 August 2025

Time: 14:00 - 14:25

Thermoelectric properties of penta-InP$_{5}$: A first-principles and machine learning study

Le Nhat Thanh (1), Pham Thi Bich Thao (1), Duy Khanh Nguyen (2,3), Vo Khuong Dien (4,5), Nguyen Thanh Tien (1)

(1) College of Natural Sciences, Can Tho University, 3-2 Road, Can Tho City 94000, Vietnam; (2)Laboratory for Computational Physics, Institute for Computational Science and Artificial Intelligence, Van Lang University, Ho Chi Minh City, Vietnam; (3) Faculty of Mechanical – Electrical and Computer Engineering, School of Technology, Van Lang University, Ho Chi Minh City, Vietnam; (4) Engineering Research Group, Dong Nai Technology University, Bien Hoa City, Vietnam; (5) Faculty of Engineering, Dong Nai Technology University, Bien Hoa City, Vietnam

High-performance thermoelectric (TE) materials with good mechanical durability are attracting significant interest for applications in smart wearable devices, particularly for harvesting energy from body heat. This study presents a comprehensive analysis of the thermoelectric and mechanical properties of a novel two-dimensional material, monolayer penta-InP$_{5}$, using first-principles calculations combined with on-the-fly machine learning potentials (FMLP). Our computational results show that penta-InP$_{5}$ exhibits outstanding thermoelectric properties at room temperature (300 K). The material achieves a remarkable figure of merit ($ZT$) of 0.51 for p-type (hole) doping and 0.42 for n-type (electron) doping. This high performance stems from an optimal combination of high electrical conductivity, a favorable Seebeck coefficient, and a very low lattice thermal conductivity (approximately 1.82 W$\cdot$m$^{-1}\cdot$K$^{-1}$). The low thermal conductivity is attributed to low phonon group velocities and strong lattice anharmonicity. Furthermore, penta-InP$_{5}$ demonstrates impressive mechanical properties, with an in-plane stiffness of about 52 N/m and a large ductile fracture strain of up to 23\% under uniaxial tension. The combination of high thermoelectric performance and excellent mechanical flexibility makes penta-InP$_{5}$ a promising candidate for next-generation energy harvesting applications, especially in wearable and flexible electronic devices.

Presenter: Lê Nhật Thanh