(3-Methylbenzo[d]thiazol-3-ium)₂Cu₃I₅: A Copper Iodide Hybrid Photoconductor Assembled via Coulomb Interaction

Abstract

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.

A halogen bonding assembled hybrid copper halide framework as a promising hypotoxicity photodetector

“…S9†). The band gap value is comparable with those of MA 2 CuCl 4 (2.48 eV), 50 (3-methylbenzo[ d ]thiazol-3-ium) 2 Cu 3 I 5 (2.40 eV) 28 and the lead-based semiconductor MAPbBr 3 (2.3 eV) 51 but severely smaller than the inorganic copper halide Cs 3 Cu 2 I 5 (3.8 eV), 52 indicating the strong UV and visible light absorption ability for BCS-CuI .…”

“…High structural dimensionality endowed by intermolecular non-covalent interactions could enable HCHs with continuous carrier transportation, which benefits their photoelectrical performance. 25–28 Although active efforts have been made to construct HCH supramolecular frameworks via intermolecular non-covalent interactions, they are mostly based on trial and error approaches instead of a targeted structural design due to that the precise control of non-covalent interactions is challenging. Halogen bonding (XB) is an attractive non-covalent interaction between a positive electrostatic region associated with a halogen atom and an electron donor such as Lewis base or anion.…”

Ultrathin covalent and cuprophilic interaction-assembled copper–sulfur monolayer in organic metal chalcogenide for oriented photoconductivity

“…S11, ESI†) 27 and the previously reported Cu-based photoconductors K 2 Cu 2 Cl 6 (∼2) 28 and (Mebti) 2 Cu 3 I 5 (1.94). 24 The transient photocurrent response of the photoconductive device shows good repeatability of photocurrent under photo-switching conditions (Fig. S12, ESI†).…”

“…This thermal stability was much higher than those of Cu(SPh–OH) and Cu(SPh–COOH), which also possessed 2D layer structures but showed onset temperatures of approximately 280 °C 12 and 1D material (Mebti) 2 Cu 3 I 5 (228 °C). 24 The finely ground polycrystalline powders were irradiated by 254 nm UV light and exposed to a moisture environment with 75% relative humidity (RH) for as long as 16 days. PXRD, transmission electron microscopy, scanning electron microscopy and infrared spectra measurements confirmed the light and moisture stabilities of [Cu(CMP)] n (Fig.…”