Computational Insight into the Physical Properties of Bulk MP (M = Li, Na, K) for Energy Applications

Area of Science:

• Computational materials science
• Solid-state physics
• Quantum chemistry

Background:

• Alkali metal phosphides (MP) are compounds with potential applications in electronics and energy.
• Understanding their fundamental electronic, optical, and thermal properties is crucial for material design.

Purpose of the Study:

• To computationally investigate the electronic, optical, and thermal characteristics of LiP, NaP, and KP.
• To assess the stability and potential applications of these materials in devices.

Main Methods:

• Density functional theory (DFT) was employed for calculations.
• Phonon spectra analysis was used to determine material stability.
• Electronic band structures, optical absorption spectra, and thermal conductivity (zT values) were computed.

Main Results:

• All investigated MP materials (LiP, NaP, KP) were found to be dynamically stable.
• LiP has an indirect band gap of 1.43 eV, while NaP and KP exhibit direct band gaps of 1.67 eV and 1.76 eV, respectively.
• The materials display strong optical absorption below 4.0 eV, suitable for solar cell applications, and high thermoelectric figure of merit (zT) values at 300 K (0.74 for LiP, 0.78 for NaP, 0.64 for KP).

Conclusions:

• The calculated properties indicate that LiP, NaP, and KP are stable compounds.
• Their strong optical absorption and high thermal performance suggest potential applications in solar cells and thermoelectric devices.