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-SbI 4 ) 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-SbI 4 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.

Transition-metal copper acts as a potential alternative for toxicity lead in exploring hypotoxicity organometal halide semiconductors (OHSs), due to its cost-effectiveness, low toxicity, earth-abundance, and near-infrared absorption. However, the known Cu-OHSs not only are limited but also exhibit unsatisfactory optoelectronic performances. Herein, we report a novel Cu-OHS (3-methylbenzo[d]thiazol-3-ium) 2 Cu 3 I 5 (denoted as Mebti-Cu 3 I 5 ) constructed by one-dimensional (Cu 3 I 5 ) 2− anionic chains charge compensated by alkylated benzothiazole counterions. The (Cu 3 I 5 ) 2− represents a rarely reported chainlike structure formed by the edge sharing of (CuI 4 ) tetrahedrons and (CuI 3 ) plane triangles. The organic countercation Mebti with a dangling methyl on the N donor precludes the formation of a coordination bond, strong hydrogen bond, and halogen bond, which further endows Mebti-Cu 3 I 5 a rare example that is assembled mainly by Coulomb interaction between inorganic and organic moieties. Mebti-Cu 3 I 5 exhibits a direct band gap value of 2.40 eV with broadband absorption in the UV and visible light region. The photoconductive film device of Mebti-Cu 3 I 5 fabricated by a recrystallization method shows good conductivity and high photoresponse, implying its potential application in a hypotoxicity photodetector. Density functional theory calculations were performed to unveil the band structure and the photoresponse mechanism.