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arXiv · 2605.14408

Strain-Enhanced Hydrogen Evolution, Electrical, Optical, and Thermoelectric Properties of the Multifunctional 2D CrSi2N4 Monolayer

Rao Uzair Ahmad·Fahd Sikandar Khan·Nasir Javed
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Abstract

First-principles density functional theory (DFT) is employed to evaluate the structural, electronic, optical, thermoelectric, and electrocatalytic properties of monolayer CrSi2N4. Its symmetric N-Si-N-Cr-N-Si-N septuple-layer structure exhibits dynamic, thermal (300 K), and mechanical stability, supported by a -8.76 eV/atom cohesive energy. PBE and HSE06 functionals reveal an indirect bandgap of 0.58 eV and 2.16 eV, respectively, driven by localized Cr-3d and N-2p states. The monolayer features 15.57 static dielectric constant and maximum absorption coefficients of 0.9 X 10^6 cm-1 (visible) and 1.4 X 10^6 cm-1 (deep-UV). Semiclassical Boltzmann calculations predict an outstanding room-temperature n-type thermoelectric power factor of 3.5 x mW/mK2. For hydrogen evolution (HER), the basal plane yields a baseline hydrogen adsorption free energy (ΔGH) of 1.05 eV at the N-site. Applying +5% expansive biaxial strain improves HER kinetics, reducing ΔGH to 0.46 eV. Thus, CrSi2N4 is a resilient, tuneable candidate for waste-heat recovery, photodetectors, and sustainable electrocatalysis.

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Rao Uzair Ahmad, Fahd Sikandar Khan, Nasir Javed. 2026-05-14. Strain-Enhanced Hydrogen Evolution, Electrical, Optical, and Thermoelectric Properties of the Multifunctional 2D CrSi2N4 Monolayer. https://doi.org/10.1016/j.surfin.2026.110092

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