Orientation Engineering for High-Performance Sb ₂ S ₃ Photodetectors

Antimony sulfide (Sb 2 S 3 ) is a promising, environmentally friendly semiconductor for novel photodetectors in view of its superior optoelectronic properties. In particular, Sb 2 S 3 has a quasi-one-dimensional (Q1D) crystallographic structure, which enables efficient charge-carrier transport for photodetectors if the film orientation can be well-controlled. In this work, high-performance Sb 2 S 3 photodetectors are developed through crystallographic orientation engineering. Hydrothermal deposition processed [hk0]-oriented Sb 2 S 3 films and close-spaced sublimation processed [hk1]-oriented Sb 2 S 3 films were successfully designed to construct photoconductive and photovoltaic Sb 2 S 3 devices, respectively. The careful studies reveal the correlation between the film orientation and device performance. The photoconductive detectors based on [hk0]-oriented films achieve enhanced responsivity of 2.032 A W –1 and detectivity of 2.24 × 10 13 Jones in view of favorable horizontal charge-carrier transport. The photovoltaic detectors based on [hk1]-oriented films deliver improved responsivity of 8.35 × 10 –2 A W –1 and detectivity of 4.15 × 10 12 Jones through efficient vertical charge-carrier transport. This work provides more insights into the dependence of the optoelectronic properties of Sb 2 S 3 devices on the crystal orientation, proving that tailoring preferential crystal orientations through deposition strategies is an effective approach to achieving high-performance photodetectors.