Thermoelectric properties of penta-InP5: A first-principles and machine learning study

Smart wearable devices that harvest energy from ambient sources, such as body heat, are gaining significant attention due to their potential in diverse applications. Thermoelectric (TE) materials, which convert thermal energy to electrical power, are critical for these devices, yet achieving both high TE performance and mechanical flexibility remains a significant challenge. Here, we investigate the TE properties of the penta-InP5 monolayer, a novel two-dimensional material, using first-principles calculations integrated with machine learning potentials. We show that penta-InP5 achieves a remarkable figure of merit, with values of 0.51 and 0.42 for hole and electron doping, respectively, at room temperature. Additionally, the material demonstrates remarkable mechanical properties, with an in-plane stiffness of 52 N/m and a fracture strain of 23% for the uniaxial strain. These findings suggest that penta-InP5 is a promising candidate for flexible, high-performance TE applications, advancing the potential of wearable energy-harvesting devices.