Ultrahigh Detectivity and Wide Dynamic Range Ultraviolet Photodetectors Based on Bi_xSn_1-xO₂ Intermediate Band...

Area of Science:

• Materials Science
• Optoelectronics
• Semiconductor Physics

Background:

• Ultraviolet (UV) photodetectors are crucial for various applications.
• Existing UV photoconductors often struggle to balance high responsivity with low dark current.
• Weak UV light detection requires high detectivity, responsivity, and a wide active area.

Purpose of the Study:

• To address the limitations of conventional UV photodetectors.
• To explore intermediate band engineering in semiconductors for improved UV detection.
• To develop high-performance UV photodetectors using Bi$_{x}$Sn$_{1-x}$O$_{2}$ films.

Main Methods:

• Fabrication of Bi$_{x}$Sn$_{1-x}$O$_{2}$ (0.017 < x < 0.041) films.
• Implementation of intermediate band engineering within the semiconductor structure.
• Characterization of photodetector performance, including detectivity, quantum efficiency, dynamic range, and recovery time.

Main Results:

• Achieved a detectivity of 6.1 × 10$^{15}$ Jones at 280 nm.
• Obtained a quantum efficiency of 2.9 × 10$^{4}$ %.
• Demonstrated a high dynamic range of 195 dB and a recovery time of approximately 1 second.

Conclusions:

• Intermediate band engineering in Bi$_{x}$Sn$_{1-x}$O$_{2}$ films enables high-performance UV photodetectors.
• The developed photodetectors significantly outperform existing technologies in key metrics.
• Bi$_{x}$Sn$_{1-x}$O$_{2}$ is a promising material for advanced UV detection applications.