High-performance UV photodetectors established on CVT-grown SnS2flakes provide an efficient way to choose 2D crystals with an optimal thickness.

Ga 2 O 3 is a promising semiconductor for solar-blind (200−280 nm) photodetectors. Two-dimensional (2D) MXenes have been widely applied in the optoelectronic area owing to their high conductivity and large specific surface area. The few-layered Ti 3 C 2 T x (Ti 3 C 2 T x -few) exhibits elevated properties compared with multilayered Ti 3 C 2 T x . Herein, we innovatively adopt a hydrothermal method to prepare Ti 3 C 2 T x -few. A Ga 2 O 3 −Ti 3 C 2 T x 3D network heterojunction is fabricated by van der Waals interaction between one-dimensional (1D) nanowires and 2D nanosheets using the light trapping effect at the interface of the heterostructure. The van der Waals force between Ga 2 O 3 and Ti 3 C 2 T x -few enhances the contact for the transfer of photoelectrons. The optimal Ga 2 O 3 −5Ti 3 C 2 T x exhibits enhanced responsivity (140.57 mA W −1 ), defectivity (4.87 × 10 12 Jones), and external quantum efficiency (68.66%), which are 6.67, 3.20, and 6.68 times higher than that of pure Ga 2 O 3 nanowires under deepultraviolet light (254 nm). The improved properties of Ga 2 O 3 −xTi 3 C 2 T x heterostructure are attributed to the high conductivity of Ti 3 C 2 T x -few, enhanced separation of photogenerated electrons and holes, decreased Schottky barrier height, enlarged depletion region, increased UV light absorption, and enhanced contact via van der Waals force between Ga 2 O 3 and Ti 3 C 2 T x . In conclusion, the Ga 2 O 3 −Ti 3 C 2 T x heterojunction extends the application of Ti 3 C 2 T x -few and provides a new tactic to improve the performance of the Ga 2 O 3 -based photodetector.

In this work, for the first time, two-dimensional (2D) non-layered CuGaS 2 nanosheets synthesized via solid-state reaction and high performance UV photodetector based on 2D nonlayered CuGaS 2 were demonstrated. The synthesized 2D CuGaS 2 shows a good crystallinity and strong optical absorption in UV light region with a direct bandgap of 2.4 eV. 2D CuGaS 2 photodetector shows an obvious photoresponse for UV lights (254 nm and 365 nm). The responsivity and detectivity values of 2D CuGaS 2 photodetector are 5.1 A W −1 and 1.67×10 11 Jones for 254 nm light (P=0.29 mW cm −2 , S=300 μm 2 ), respectively. Our results demonstrate that 2D non-layered CuGaS 2 is a promising candidate for application in UV photodetection devices.

Gallium oxide (Ga2O3) has become a viable candidate for certain types of high-power devices due to its large energy bandgap of 4.9 eV, which has attracted widespread attention. In particular, Ga2O3 nanowire structures have more unique properties due to its larger specific surface area for the high performance solar-blind ultraviolet (UV) photodetectors. In this work, the ultrafine Ga2O3 nanowire network structure is obtained on the sapphire substrate with an Au catalyst by chemical vapor deposition method at 960 °C for 10 min. We can confirm that the growth of the nanowire follows the vapor–liquid–solid growth mechanism and is a β-type Ga2O3 crystal through the performance test results. A solar-blind UV photodetector based on the nanowires network shows an apparent response to solar-blind UV light and almost no response to 365 nm wavelength. Furthermore, the on–off ratio, light responsivity, and response time are also measured under a 254 nm wavelength UV light irradiation, respectively. This work provides a new preparation method to improve the performance of solar-blind UV photodetector.

Monoclinic gallium oxide (β-Ga2O3) is a super-wide bandgap semiconductor with excellent chemical and thermal stability, which is an ideal candidate for detecting deep ultraviolet (DUV) radiation (wavelength from 200 nm to 280 nm).