A high-sensitivity PtNPs@CsCu2I3 single-crystal UV photodetector for precision sunscreen protection monitoring

Abstract

To address the public health challenge posed by skin cancer, there is an urgent necessity to devise bendable and wearable ultraviolet (UV) photodetectors capable of monitoring the carcinogenic UV in everyday life on a real-time basis and with individualized coverage. This paper proposes a new plasmonic enhancement scheme using platinum nanoparticles (PtNPs) decorated on one-dimensional (1D) CsCu₂I₃ single-crystals (SCs) to give high-performance and highly stable UV photodetection. Surface-coated PtNPs provide a plasmonic response with a maximum at 341 nm, which essentially coincides with the absorption edge of CsCu₂I₃. This alignment contributes to a considerable increase in the light harvesting and carrier generation/separation efficiency. The optimized PtNPs@CsCu₂I₃ photodetector is characterized by outstanding performance under 340 nm illumination at 5 V bias, achieving a responsivity of 26.32 A W⁻¹, a specific detectivity of 5.97 × 10¹³ Jones, and ultrafast sub-millisecond response times (510 μs rise/619 μs decay). Moreover, the detector is very environmentally stable, and the performance of the detector remains at more than 95% of the original after 90 days ambient air storage in the absence of encapsulation. In a practical demonstration for sunscreen UV-blocking assessment, the device shows high linearity (R² = 0.99) and reliable accuracy for the different sunscreens with varying strength factors. This contribution does more than merely offer an efficient pathway to achieving high-performance copper-based perovskite photodetectors, it also suggests their possible applications in the real-world, which may be wearable health-commerce tags, environmental sensors, and optical communication structures.