Te_x Se_1-x Photodiode Shortwave Infrared Detection and Imaging

Area of Science:

• Materials Science
• Optoelectronics
• Semiconductor Devices

Background:

• Short-wave infrared (SWIR) detectors are crucial for autonomous driving, food safety, disease diagnosis, and research.
• Existing SWIR cameras like InGaAs face challenges with complex integration, high costs, and limited resolution.
• Need for cost-effective, high-performance SWIR detectors compatible with standard fabrication processes.

Purpose of the Study:

• To develop a low-cost, high-performance, and stable Te$_{x}$Se$_{1-x}$ photodiode detector for SWIR imaging.
• To demonstrate CMOS compatibility for direct integration with readout circuits.
• To explore applications in material identification and masking imaging.

Main Methods:

• Fabrication of Te$_{x}$Se$_{1-x}$ thin films using CMOS-compatible low-temperature evaporation and post-annealing.
• Characterization of the photodiode detector's spectral response, detectivity, bandwidth, and dynamic range.
• Assessment of device stability using Si$_{3}$N$_{4}$ packaging.

Main Results:

• Broad spectral response from 300-1600 nm.
• Room-temperature specific detectivity of 1.0 × 10$^{10}$ Jones and a -3 dB bandwidth up to 116 kHz.
• Achieved fastest response among Te-based photodiodes with dark current density 7 orders of magnitude lower than alternative Te-based devices.

Conclusions:

• The developed Te$_{x}$Se$_{1-x}$ photodiode detector offers a low-cost, high-performance, and stable SWIR imaging solution.
• CMOS-compatible fabrication enables direct integration, paving the way for advanced SWIR imaging chips.
• Demonstrated potential for applications in material identification and masking imaging, meeting vehicular requirements.