Enhancing Thermoelectric Performance of Cd₃P₂ by Alloying with Dirac Material Cd₃As₂

Abstract

This study systematically explores the electrical and thermal properties of Cd₃P₂ by alloying it with the Dirac material Cd₃As₂, employing a combined experimental and theoretical approach. The findings demonstrate three distinct characteristics of this solid solution system: i) The continuous solid solution formation between Cd₃P₂ and Cd₃As₂ enables the tuning of the band structure. ii) Increasing As content leads to a reduction in effective mass, decreased deformation potential, and a substantial enhancement in carrier mobility. iii) The system exhibits phosphorus vacancy generation, which creates donor levels within the band gap and consequently impacts thermoelectric performance. Specifically, an ultrahigh mobility exceeding 7 × 10³ cm² V⁻¹ s⁻¹ is achieved in Cd₃PAs. This substantial improvement in mobility across the entire temperature range resulted in a twofold increase in the power factor and a marked enhancement in thermoelectric performance, particularly in the low-temperature region. These results provide foundational insights into the thermoelectric behavior governed by the interplay between the semiconductor Cd₃P₂ and the Dirac material Cd₃As₂, establishing a framework for further research and performance optimization of this solid solution system.