Tuning the physical properties of monolayer germanium carbide through strain engineering

Due to its massive direct bandgap and large exciton binding energy, two-dimensional germanium carbide (2D-GeC) has already piqued the interest of many researchers. We primarily focus on the biaxial strain effect on its electronic, vibrational, optical, and structural properties using density functional theory calculations. At its direct K-point, the electronic bandgap of monolayer GeC is approximately 2.04 eV, and this bandgap is brought down to about 1.96 eV when the spin–orbit coupling (SOC) effect is incorporated. The bandgap demonstrates a decline and rise in elevation as compressive and tensile strains are applied within the range of − 6 to + 6%. Our results suggest that monolayer GeC becomes unstable when subjected to compressive strains beyond − 2%, but it remains stable up to + 6% tensile strain. The dynamic stability of the 2D-GeC structure is evident as it can tolerate a notable degree of biaxial strain. Furthermore, the strain-induced variations in the optical properties of monolayer GeC, including the real and imaginary dielectric spectra and electron energy loss function, reveal its excellent light absorption capacity across both the infrared and visible spectrums. Bandgap modulation depends on such SOC impacts may potentially contribute to the next generation of optoelectronic and spintronic devices using 2D-GeC.