Dimethylamine Bismuth Iodide: A Lead-Free Perovskite Enabling Ultra-Sensitive UVC Photodetection with Low Operating...

Area of Science:

• Materials Science
• Solid-State Physics
• Optoelectronics

Background:

• Traditional ultraviolet (UV) photodetectors (PDs) face limitations in cost, fabrication, and performance.
• There is a need for advanced materials for efficient UV detection, especially in the UVC spectrum.

Purpose of the Study:

• To introduce dimethylamine bismuth iodide (DMABI) as a novel lead-free perovskite material for UV PDs.
• To investigate the structural and electronic properties of DMABI for UV photodetection.
• To evaluate the performance of DMABI-based UV PDs.

Main Methods:

• Synthesis and characterization of DMABI perovskite.
• Fabrication of UV photodetector devices using DMABI.
• Electrical and optical performance testing of the fabricated PDs, including dark current, on/off ratio, detectivity, responsivity, and external quantum efficiency.

Main Results:

• DMABI exhibits an ultralow dark current (0.12 pA at 0.05 V) and a high on/off ratio (7.1 × 10⁴).
• Peak detectivity reached 3.18 × 10¹³ Jones, with high responsivity (1.46 A/W) and external quantum efficiency (up to 717%).
• The unique isolated octahedral structure of DMABI facilitates efficient charge carrier transport and reduces dark current.

Conclusions:

• DMABI is a promising, low-cost, lead-free perovskite material for high-performance UV photodetection, particularly in the UVC region.
• The molecular structure of DMABI is key to its superior optoelectronic properties.
• DMABI offers a viable alternative to traditional UV PD materials, with potential for future advancements.