abstract
- The effect of formaldehyde (CH2O) as a surface modifier of PbTe is evaluated. Global descriptors are calculated through density functional theory to delve into the nature of the interaction between CH2O and the PbTe surface. The CH2O molecule is structurally optimized using the PBE exchange-correlation functional and ultrasoft pseudopotentials. Subsequently, vertical ionization energies and vertical electron affinities are calculated to elucidate how the CH2O molecule behaves energetically concerning the electron removal and gain, respectively. To determine regions with higher and lower charge accumulation, the electrostatic potential on the van der Waals isosurface is mapped. It is inferred that the theoretical knowledge generated is useful for proposing modes of CH2O adsorption on the PbTe surface, results that rationalize the faces exposed by PbTe after surface treatment. The optimized structures of the composite systems showed a close correlation between the change in surface energy (¿¿) and the exposed faces of PbTe. Finally, through Wulff construction, the morphology of PbTe interacting with CH2O as a process control agent is determined. It was found that formaldehyde helps decrease the surface energy of the exposed faces of PbTe, leading to decahedra and faceted morphologies. © (2025), (Sociedad Mexicana de Fisica). All rights reserved.