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Massive two-dimensional (2D) Bi 2 O 3 nanosheets (NSs) were synthesized adopting a facile solution route. It can be distinctly perceived that the average dimension of the Bi 2 O 3 NSs was mainly centered in the range of 1–2 μm and the thickness reached about 110 nm. Afterward, the self-powered ultraviolet photodetector (UVPD) was successfully prepared established on the 2D Bi 2 O 3 NSs, which exhibited high photosensitivity and robust stability in exposure to UV light, accompanied with the fast rise time of ∼33 ms and decay time of ∼47 ms. In addition, the Bi 2 O 3 NSs UVPD could perform a stable operation over a wide range of UV light intensities. Moreover, the photodetection mechanism for the Bi 2 O 3 NSs UVPD was also illustrated. • Massive two-dimensional Bi 2 O 3 nanosheets were synthesized adopting a facile solution route. • Exposure to UV light, Bi 2 O 3 nanosheets UV photodetector exhibited high photosensitivity free of the external power. • Bi 2 O 3 nanosheets UV photodetector could perform stable operation over the wide range of UV light intensities. [ABSTRACT FROM AUTHOR]

Currently, bismuth oxychalcogenide family (Bi 2 O 2 X, X S, Se, Te), led by Bi 2 O 2 Se with unique characteristics, have emerged as promising candidates for high-performance optoelectronic devices. Herein, the novel Bi 2 O 2 S flowers with hierarchical structure have been successfully prepared via a facile hydrothermal method with only 3 h of reaction. The as-prepared Bi 2 O 2 S flower is composed of many ultrathin nanosheets (NSs) with a thickness of about 12–16 nm. And the possible formation mechanism of ultrathin NSs self-assembled Bi 2 O 2 S flowers is further analyzed. In addition, a self-powered infrared photodetector based on Bi 2 O 2 S flowers, which can work without an external power, is designed. Under illumination at 850 nm light, the Bi 2 O 2 S flowers photodetector exhibits well photoresponse switching behaviors, of which the high responsivity, specific detectivity and fast response time reach up to 9.48 mA/W, 9.96 × 1010 Jones and 227.7 ms, respectively. Of particular note, the Bi 2 O 2 S flowers photodetector also possesses the eximious stability. [Display omitted] ● The Bi 2 O 2 S flowers composed of 2D ultrathin nanosheets were prepared on the fluorine-doped tin oxide substrate. ● The Bi 2 O 2 S flowers infrared photodetector exhibits a high responsivity of 9.48 mA/W and detectivity of 9.96 × 1010 Jones. ● The Bi 2 O 2 S flowers infrared photodetector possesses eximious stability, and can operated without an external power source. [ABSTRACT FROM AUTHOR]

• Scaly-like hollow SnSe nanotubes (NTs) were synthesized by a green and rapid solution method. • Light utilization efficiency is improved due to unique scaly-like hollow structure and large surface area of the SnSe NTs. • SnSe NTs infrared photodetector can realize efficient and stable IR light detection free of the external power. [Display omitted] SnSe nanotubes (NTs) have been successfully synthesized via a simple solution method. The as-synthesized tubular crystals with orthorhombic structure are composed of numerous scaly nanosheets which distributed hierarchically. The average diameter of the SnSe NTs is roughly 180 nm and length primarily concentrate in the range of 1–3 µm. It was found that Se nanowires were served as a template and as an only source of Se ion for the formation of SnSe NTs. Furthermore, a novel self-powered infrared photodetector (IRPD) established on the SnSe NTs with desirable detection performance was fabricated. Exposed to IR illumination of 830 nm, the SnSe NTs IRPD displays a maximal photocurrent density of 46.46 nA/cm2 and a rapid photoresponse, together with the rise time and decay time approach up to 0.174 s and 0.349 s, respectively. Meanwhile, it can be recognized that the SnSe NTs IRPD remain consistent and repeatable at zero voltage. Moreover, a plausible mechanism for IR detection based on the SnSe NTs IRPD are also discussed. [ABSTRACT FROM AUTHOR]

Bismuth telluride (Bi2Te3), as an emerging two-dimensional (2D) material, has attracted extensive attention from scientific researchers due to its excellent optoelectronic, thermoelectric properties and topological structure. However, the application research of Bi2Te3 mainly focuses on thermoelectric devices, while the research on optoelectronic devices is scarce. In this work, the morphology evolution and growth mechanism of 2D Bi2Te3 nanosheets with a thickness of 12 ± 3 nm were systematically studied by solvothermal method. Then, the Bi2Te3 nanosheets were annealed at 350 °C for 1 h and applied to self-powered photoelectrochemical-type broadband photodetectors. Compared with the as-synthesized Bi2Te3 photodetector, the photocurrent of the photodetector based on the annealed Bi2Te3 is significantly enhanced, especially enhanced by 18.3 times under near-infrared light illumination. Furthermore, the performance of annealed Bi2Te3 photodetector was systematically studied. The research results show that the photodetector not only has a broadband response from ultraviolet to near-infrared (365–850 nm) under zero bias voltage, but also obtains the highest responsivity of 6.6 mA W−1 under green light with an incident power of 10 mW cm−2. The corresponding rise time and decay time are 17 ms and 20 ms, respectively. These findings indicate that annealed Bi2Te3 nanosheets have great potential to be used as self-powered high-speed broadband photodetectors with high responsivity. [ABSTRACT FROM AUTHOR]