In recent years, the integration of two-dimensional (2D) nanomaterials, especially transition metal chalcogendies (TMCs) and dichalcogendies (TMDCs), into electronic devices have been extensively studied owing to their exceptional physical properties such as high transparency, strong photoluminescence, and tunable bandgap depending on the number of layers. Herein, we report the optoelectronic properties of few-layered MoSe ₂ -based back-gated phototransistors used for photodetection. The photoresponsivity could be easily controlled to reach a maximum value of 238 AW ⁻¹ under near-infrared light excitation, achieving a high specific detectivity ( D * = 7.6 × 10 11 cm Hz 1/2 W − 1 ) . Few-layered MoSe ₂ exhibited excellent optoelectronic properties compared with those reported previously for multilayered 2D material-based photodetectors, indicating that our device is one of the best high-performance nanoscale near-infrared photodetectors based on multilayered two-dimensional materials.

Two-dimensional (2D) layered materials exhibit unique optoelectronic properties at atomic thicknesses. In this paper, we fabricated metal–semiconductor–metal based photodetectors using layered gallium selenide (GaSe) with different thicknesses. The electrical and optoelectronic properties of the photodetectors were studied, and these devices showed good electrical characteristics down to GaSe flake thicknesses of 30 nm. A photograting effect was observed in the absence of a gate voltage, thereby implying a relatively high photoresponsivity. Higher values of the photoresponsivity occurred for thicker layers of GaSe with a maximum value 0.57 AW ⁻¹ and external quantum efficiency of of 132.8%, and decreased with decreasing GaSe flake thickness. The detectivity was 4.05 × 10 ¹⁰ cm Hz ^1/2 W ⁻¹ at 532 nm laser wavelength, underscoring that GaSe is a promising p-type 2D material for photodetection applications in the visible spectrum.

TiO₂–SiO₂ nanocomposite thin films have gained the attention of the scientific community due to their unique physical and chemical properties. In this paper, we report on the fabrication and characterization of a TiO₂–SiO₂ nanocomposite disk-shaped target. The target was used for the deposition of TiO₂–SiO₂ nanocomposite thin films on fluorine-doped tin oxide/glass substrates using the pulsed laser deposition (PLD) technique. The thicknesses of the thin films were fixed to 100 nm, and the deposition temperature ranged from room temperature to 300 °C. As revealed by the microstructural and morphological characterizations revealed, the TiO₂–SiO₂ nanocomposite thin films are amorphous and display homogeneous distribution. The determined values of the indirect optical band gap range from 2.92 to 3.07 eV, while those of the direct optical band gap lie between 3.50 and 3.55 eV. Additionally, as the deposition temperature decreases, the light transmission increases in the visible and in the ultraviolet ranges, which is suitable for flexible perovskite solar cells. This research can uncover new insights into the fabrication of amorphous TiO₂–SiO₂-based nanostructured thin films using the PLD technique for perovskite solar cell technology.

Unidimensional photonic crystal-based biosensors have gained much attention in the area of blood glucose measurement. In this paper, we propose two novel designs based on two-dimensional (2D) Van der Waals materials. The first 1D photonic crystal design consists of multilayers of 2D gallium sulfide and 2D muscovite mica [GaS/Mica]^ND[GaS/Mica]^N, and the second design consists of multilayers of 2D gallium sulfide [GaS/G]^ND[GaS/G]^N. We conducted a numerical analysis using the transfer matrix method to investigate the properties of photonic crystals, both with and without defect layers, in order to assess their suitability for biosensing applications. The biosensors’ performances were investigated as a function of glucose concentration, revealing a high sensitivity of 832 nm/RIU, a notable figure-of-merit of 1.46 × 10⁵ RIU⁻¹, a Q-factor exceeding 10⁵, and a minimum limit of detection of 3.4 × 10⁻⁷ RIU. Finally, we modified the [GaS/G]^ND[GaS/G]^Nstructure in order to enhance the sensitivity nearly 5-fold. The proposed biosensors offer the advantage of being label-free, making them promising platforms for the sensitive and reliable detection of blood glucose levels.