Position-Sensitive Array Photodetector Based on Comb-Like CdS Nanostructure with Cone-Shape Branches

2D microscale position-sensitive detectors (PSDs) are highly desirable with the degree of integration increase and the size reduction of nanodevices, which are still unavailable. Multichannel devices with outstanding photoelectric properties attract considerable interest as powerful building blocks to be applied in on-chip systems. Here, based on a highly ordered comb-like CdS nanowire array with cone-shape branches through a one-step synthesis strategy, a high-resolution 2D position-sensitive photodetector is realized through variable resistance in different transportation routes and variable optical responses at different parts of the cone-shape branches, which enable accurate position identification of incident light in various zones of nanowire arrays according to photocurrent changes. In a broadband from 310 to 560 nm, the PSD exhibits high sensitivity with 85 and 58 KΩ µm⁻¹ in the trunk and branch part, respectively, and an ultrafast optical response shorter than tens of millisecond. Moreover, a lower conductivity change rate per unit temperature of the PSD (1.625 × 10⁻⁹ A V⁻¹ K⁻¹) than that of commercial Si-based PSDs (≈6.67 × 10⁻⁷ A V⁻¹ K⁻¹) reveals outstanding low-temperature performance. Finally, the multichannel nanostructure based PSD with nanoscale resolution is applied to high-accuracy quadrant photodetectors.