Dual sulfur sources redox dynamics guided growth of 〈hk1〉-oriented SbS microrods: lattice strain modulation for ultra-low dark current.

Antimony trisulfide (SbS) has emerged as a promising inorganic semiconductor for optoelectronics due to its distinctive anisotropic crystal structure and suitable bandgap (∼1.7 eV). While hydrothermal synthesis remains challenging for achieving high crystallinity and controlled morphology, we developed an innovative dual‑sulfur precursor strategy utilizing sodium thiosulfate (STS) and thioacetamide (TAA) at a 7:2 M ratio with SbCl. This synergistic sulfur source system enables precise control over S release kinetics, significantly enhancing crystal growth rates while promoting preferential [hk1] orientation in the resulting microrods. The optimized SbS-based photodetector achieves superior photodetection performance with a 9.8 A·W responsivity at 560 nm (5 V bias), 2153 % external quantum efficiency, fast response (182/320 ms), broadband detection (400-750 nm), and high detectivity (1.27 × 10 Jones), while its defect-suppressed microrod structure enables an ultralow dark current of 4 × 10 A (5 V bias), surpassing most reported SbS devices. This synthesis method effectively suppresses defects in SbS microrods, advancing their potential for practical optoelectronic applications.