Researchers have developed low-power visible and near-infrared phototransistors using mechanically exfoliated multilayer WS₂. These phototransistors exhibit n-type conduction and slightly different Schottky barriers at the drain and source contacts. They can operate in self-powered mode, generating both current and voltage when exposed to light. The devices show high responsivity (4.5 μA/W) around 1250 nm, making them promising for telecommunication applications. The study investigates the optoelectronic properties of WS₂ phototransistors, including their photoresponse in the visible and near-infrared ranges. The devices demonstrate high responsivity and specific detectivity, with a responsivity of up to 4.5 μA/W in the near-infrared range. The phototransistors also show persistent photoconductivity, which makes them suitable for photonic neuromorphic devices. The phototransistors were fabricated on Si/SiO₂ substrates using mechanical exfoliation and Ti/Au contacts. The devices were tested under various conditions, including different temperatures and incident optical powers. The results show that the phototransistors perform well at low incident power and exhibit a high responsivity at 1250 nm. The study also explores the light absorption properties of the devices in the visible and near-infrared ranges. The results indicate that the devices have a high responsivity in the near-infrared range, which is attributed to the presence of interlayer excitons. The high responsivity in the near-infrared range makes the devices promising for applications in optical telecommunications. The research highlights the potential of WS₂-based phototransistors for optoelectronic applications, particularly in telecommunications. The devices show promising performance in terms of responsivity, detectivity, and persistent photoconductivity. The study provides a comprehensive understanding of the optoelectronic properties of WS₂-based phototransistors and their potential applications.Researchers have developed low-power visible and near-infrared phototransistors using mechanically exfoliated multilayer WS₂. These phototransistors exhibit n-type conduction and slightly different Schottky barriers at the drain and source contacts. They can operate in self-powered mode, generating both current and voltage when exposed to light. The devices show high responsivity (4.5 μA/W) around 1250 nm, making them promising for telecommunication applications. The study investigates the optoelectronic properties of WS₂ phototransistors, including their photoresponse in the visible and near-infrared ranges. The devices demonstrate high responsivity and specific detectivity, with a responsivity of up to 4.5 μA/W in the near-infrared range. The phototransistors also show persistent photoconductivity, which makes them suitable for photonic neuromorphic devices. The phototransistors were fabricated on Si/SiO₂ substrates using mechanical exfoliation and Ti/Au contacts. The devices were tested under various conditions, including different temperatures and incident optical powers. The results show that the phototransistors perform well at low incident power and exhibit a high responsivity at 1250 nm. The study also explores the light absorption properties of the devices in the visible and near-infrared ranges. The results indicate that the devices have a high responsivity in the near-infrared range, which is attributed to the presence of interlayer excitons. The high responsivity in the near-infrared range makes the devices promising for applications in optical telecommunications. The research highlights the potential of WS₂-based phototransistors for optoelectronic applications, particularly in telecommunications. The devices show promising performance in terms of responsivity, detectivity, and persistent photoconductivity. The study provides a comprehensive understanding of the optoelectronic properties of WS₂-based phototransistors and their potential applications.