Scrutinizing the structural, opto-electronic, mechanical, and thermoelectric properties of semiconductor lead-free double perovskites A₂AgMoBr₆ (A = K, Rb, Cs)

The structural, optical, electronic, and transport properties of A₂AgMoBr₆ (A = K, Rb, Cs) have been examined using first-principles calculations in the present study. The measured value of Paugh’s ratio (B/G) in mechanical computations discloses the material’s ductility. The computed negative value of enthalpy of formation (ΔH) suggests that the examined materials are stable. The assessment of band structure reveals that the A₂AgMoBr₆ (A = K, Rb, Cs) compound has an indirect bandgap (L-X). The materials under examination have an incredible absorption coefficient (α(ω)) in the ultraviolet and visible regions of the light spectra, making them suitable for photovoltaic and optical equipment manufacturing. In addition, the transport characteristics have been projected using the BoltzTraP code at temperatures ranging from 100 to 1000 K. The estimated value of the figure of merit (zT) 0.89, 0.92, and 0.85 for K, Rb, and Cs respectively at room temperature suggests that A₂AgMoBr₆ (A = K, Rb, Cs) compounds are perfect contenders for thermoelectric device applications.