Two-dimensional (2D) antimony-based materials have garnered significant interest due to their intrinsic structural anisotropy, tunable electronic band structures, and superior carrier transport properties, rendering them highly promising for next-generation microelectronic and optoelectronic applications. Nevertheless, research on ternary antimony-based compounds remains at an early stage, despite their compositional versatility and potential for synergistically modulating electronic and optical properties through element-specific engineering. Here, we report a novel 2D ternary antimony chalcogenide oxide, Sb2S2O, which features a low-symmetry layered structure and pronounced in-plane anisotropy. The layered Sb2S2O crystals exhibit excellent broadband photoresponse performance across the 254-940 nm range, achieving a remarkable responsivity of 11.3 A W-1 and a specific detectivity of 6.5 × 1011 Jones. Moreover, the photodetectors demonstrate polarization-angle-dependent sensitivity spanning 266-808 nm, with the structural anisotropy of Sb2S2O giving rise to a maximum dichroic ratio of approximately 1.48 at 633 nm. Notably, modulation of the polarization angle enables dynamic control over the spatial distribution of photoexcited carriers and the interfacial potential landscape, thereby allowing efficient tuning of the device's optical response. This polarization-dependent tunability further allows the photodetector to operate in a dual-mode configuration for intelligent imaging, simultaneously achieving high-sensitivity detection and programmable contrast enhancement. The integration of deep learning algorithms with the multifunctional optoelectronic characteristics of Sb2S2O positions this material as a promising candidate for next-generation intelligent photodetection and adaptive vision technologies.
Liu et al. (Tue,) studied this question.