(3-Phenylpyridin-1-ium)SbI₄: Coulomb Interaction-Assembled Lead-free Hybrid Perovskite-like Semiconductor

The environmental toxicity of Pb in inorganic–organic hybrid perovskite presents a major hurdle to commercialization, which has triggered intense research on exploring Pb-free alternatives. Soft interaction, especially Coulomb interaction not only enriching the synthesis strategy but endowing a unique property to the derived materials, is appealing for constructing Pb-free alternatives; however, less has been reported. We herein demonstrate the construction of a Sb-based hybrid perovskite-like semiconductor (3-phenylpyridin-1-ium)SbI4 (denoted as 3ppi-SbI4) via the “Coulomb interaction strategy”. Therein, the zigza (SbI4)− chains interact with the 3ppi countercations through Coulomb interaction only in the crystal lattice. It has good moisture, sunlight, and UV light stabilities. Further, 3ppi-SbI4 exhibits excellent light absorption, direct band gap feature, good photoconduction, and excellent repeatability of photocurrent, which all imply its potential as a Pb-free, light-absorbing candidate for optoelectronic application. Theoretical calculations disclose that the photoresponse is mainly ascribed to the electron transitions within (SbI4)− chains, as well as between inorganic and organic moieties.