Screening on optoelectronic and thermoelectric response of novel Zintl phase CaMg2Pn2 (Pn = P, As) for renewable energy applications: A first principles method

Abstract

The study on the zintl compounds CaMg₂Pn₂ (Pn = P, As), compounds utilizing density functional theory (DFT) through the WIEN2k code comprehensively examines its structural, electronic, optical, and thermoelectric properties. Generalized gradient approximation (GGA) and modified Becke-Johnson (mBJ) potentials are used to determine the exchange-correlation potential. The electronic analysis of the CaMg₂Pn₂ compounds, reveals that this material behaves as a semiconductor, possessing an indirect band gap of 1.87 eV and 1.76 eV. The study of the optical properties of CaMg₂Pn₂, including its refractive index, extinction coefficient, electron energy loss, dielectric tensor, and optical conductivity, alongside the specific finding that it does not absorb energy below 2.60 eV, provides valuable insights. In addition, BoltzTrap is a software used to calculate the transport properties against temperature (200–1200K) and chemical potential of materials based on their electronic structures. The highest power-factor (PF) 5.57 × 10¹¹ W/K²ms, 5.0 × 10¹¹ W/K²ms at 300 K was attained for CaMg₂Pn₂ (Pn = P, As) compounds. These findings suggest that CaMg₂Pn₂ has potential as a thermoelectric material with interesting characteristics. Because of their exceptional optoelectronic as well as high PF values, this group of materials holds significant promise for applications in optoelectronic and thermal devices. Their properties suggest potential advancements in fields such as solar energy, light emission technologies, and efficient thermal management systems.