Exploring the physical properties of novel ACu3S3 (A = Sc, Y) semiconductors via first-principles calculation

Abstract

Some of the distinguishing features of direct band gap ternary-type semiconductors include their adjustable optoelectronic properties and high thermal stability. The state-of-the-art density functional theory is employed to investigate the complex interplay in novel ACu3S3 (A = Sc, Y) ternary chalcogenides' electronic, optical, thermodynamic, and thermoelectric features. Based on the results, direct energy gaps nature in both these materials were observed as a result of the S-p and the Sc/Y-d orbital hybridizations. The YCu3S3 possesses a greater energy gap at the (Γ) point, resulting in higher effective mass for holes and lower effective mass for electrons as compared to ScCu3S3. The prime distinctive peaks in the ε1(ω) are observed in the visible range which then drops to zero at 8.5 eV and 8.0 eV for ScCu3S3 and YCu3S3, respectively. Both ScCu3S3 and YCu3S3 exhibited strong absorption over the whole visible and ultraviolet regions. From the noticed peaks in the reflectivity spectra, these materials can be employed efficiently as ultra-violet reflectors. The drop in the Grüneisen parameter with rising temperature shows that some vibrational modes relaxed as the temperature rises. The ScCu3S3 and YCu3S3 show a p-type conduction nature due to the positive value of the Seebeck coefficient over the entire temperature range.