High-Performance Uncooled Mid-Infrared Detector Based on a Polycrystalline PbSe/CdSe Heterojunction

Area of Science:

• Materials Science
• Optoelectronics
• Infrared Technology

Background:

• Developing uncooled mid-wavelength infrared (MWIR) detectors is challenging due to material properties and manufacturing limitations.
• Existing detectors often require complex fabrication processes, limiting their commercial viability.
• Photovoltaic (PV) detectors offer potential advantages over photoconductive (PC) detectors for uncooled applications.

Purpose of the Study:

• To design and manufacture a high-performance, uncooled polycrystalline PbSe/CdSe heterojunction PV detector.
• To evaluate the detectivity and performance of the fabricated detector under varying temperatures.
• To assess the suitability of this detector for low-cost, high-performance MWIR focal plane array imaging.

Main Methods:

• Fabrication of a polycrystalline PbSe/CdSe heterojunction PV detector using vapor physical deposition.
• Characterization of the detector's performance, including peak detectivity measurements at different temperatures (298 K and 220 K).
• Comparison of the device's performance with existing PbSe photoconductive detectors.

Main Results:

• The 10 μm × 10 μm PbSe/CdSe PV detector achieved peak detectivities of 7.5 × 10⁹ cm·Hz^1/2·W^-1 at 298 K and 3 × 10¹⁰ cm·Hz^1/2·W^-1 at 220 K.
• Performance is comparable to standard PbSe photoconductive detectors.
• The sensitization-free fabrication process ensures high replicability and yield.

Conclusions:

• The developed PbSe/CdSe heterojunction PV detector demonstrates high performance for uncooled MWIR detection.
• The sensitization-free process simplifies manufacturing, enhancing replicability and yield.
• These detectors are promising for cost-effective, high-performance MWIR focal plane array imaging in commercial applications.