High-Performance Dual-Mode UV Photodetection from a Single Maneuverable X-Shaped Cs₃Cu₂I₅ Microcrystal

Area of Science:

• Materials Science
• Optoelectronics
• Nanotechnology

Background:

• Ultraviolet photodetectors (UV PDs) are crucial for various applications.
• Precise manipulation of microcrystals (MCs) for device fabrication remains a significant challenge.
• Existing methods struggle with mass processing and performance enhancement of UV PDs.

Purpose of the Study:

• To demonstrate precise manipulation of a single Cs3Cu2I5 microcrystal for high-performance UV PD fabrication.
• To investigate the dual-mode photoresponse of UV PDs based on microscale perovskite-inspired materials.
• To achieve enhanced detection performance and stability in ambient conditions.

Main Methods:

• Utilized optical focusing, probe micromanipulation, and direct-write photolithography for MC manipulation.
• Fabricated UV PDs on different limbs of a single X-shaped Cs3Cu2I5 MC.
• Characterized the photoresponse under 254 nm (UVC) and 310 nm (UVB) irradiations.

Main Results:

• Achieved high responsivity (up to 3376 A/W) and specific detectivity (up to 2.37 × 10^14 Jones) at low light intensity (2.59 μW/cm^2).
• Demonstrated a high on/off ratio (up to 1.79 × 10^2) at a 5 V bias.
• Exhibited extraordinary stability with stable photocurrents over 8 hours of continuous dual-mode UV irradiation in ambient air.

Conclusions:

• Successfully manipulated a single X-shaped Cs3Cu2I5 MC to create high-performance dual-mode UV PDs.
• The developed techniques offer a pathway for mass processing and performance improvement of MC-based UV PDs.
• Findings inspire the development of advanced UV PDs using microscale perovskite-inspired copper halides and other semiconductor MCs.