SiC/SiO2/SnO2 Single Core–shell Nanowire Ultraviolet Photodetector with Radial Heterojunction: A Promising Strategy to Break the Responsivity-Speed Trade-Off

The utilization of a single silicon carbide (SiC) nanostructure-based photodetector (PD) is highly promising for developing MEMS devices, particularly in challenging environments such as high-temperature, high radiation, and corrosive environments. However, achieving a simultaneous improvement in responsivity and response speed is a challenge due to the inherent trade-off between these two parameters resulting from the limitations in light absorption capability and photoelectric transmission efficiency. To overcome this bottleneck, a novel single SiC/SiO₂/SnO₂ nanowire heterojunction ultraviolet (UV) PD is constructed based on the interface effect, resulting in a responsivity of 38188 A W⁻¹ and rise and decay times of 15 and 10 ms, respectively. The novel core–shell radial heterojunctions not only achieve high light absorption and shorten the distance for photo-generated carriers, ensuring a large optoelectronic gain and fast response time of the device, but also mitigate the individual differences among nanowires. The devices have potential applications in optoelectronic imaging, flame detection, and secure communication fields.