Interfacial N -> Sb Nonbonded Interaction Enhances the Photoelectronic Performance of PVP-Capped Sb2S3 Amorphous Colloids

The bonded or nonbonded interactions at the interface of ligands and surface atoms are a core issue in engineering the surface chemistry and (photo) electronic properties of semiconductor colloidal solids. Herein, we demonstrate the interfacial Lewis acid-base N -> Sb nonbonded interaction: N atoms in polyvinylpyrrolidone (PVP) molecules acting as an electron donor to enhance the photoconductivity and -responsivity of PVP-capped Sb2S3 amorphous semiconductor colloids. The electron donation effect of PVP N atoms in the N -> Sb interaction is backed by the upper shift of N 1s binding energy in the X-ray photoelectron spectra (XPS) and the relevant literature. The repulsion of lone pair electrons (LPEs) of N atoms is thought to make 5 s(2) LPEs of Sb atoms retract from Sb nuclei with an increased orbital volume, giving rise to high probability for the overlap and coupling of 5 s(2) LPEs among neighboring Sb atoms on the surface of Sb2S3 amorphous colloids. Such a spatially and energetically matched electron-electron coupling greatly contributes to the photoelectronic performance enhancement of amorphous Sb2S3. We believe that the electron coupling and improved (photo) electronics can be generalized in many semiconductors containing ns(2) LPE metal cations by the surface/interface Lewis acid-base interactions with suitable ligands.