Azad Rahman¹, Jay Radadiya¹, Baolai Liang², Richard S. Kim³, Seunghyun Lee^1
1University of Texas at Arlington, Arlington, TX
²University of California - Los Angeles, Los Angeles, CA
³Laser Components, Chandler, AZ
Our study focuses on the design and characterization of an InAs/GaSb 4ML/8ML SL-based mid-wave (~3-4 µm) infrared (MWIR) PIN photodetector to operate at room or near-room temperature. Detectors, specifically in the 3-4 µm wavelength range, have potential for extensive applications in environmental gas sensing, such as methane (CH₄). Since its absorption spectrum lies in 3.4-3.5 µm region, MWIR detectors can play a vital role in detecting methane concentration in methane-sensitive environments. Current state-of-the-art MWIR detector technologies are dominated by mercury cadmium telluride (MCT)-based devices. MCT-based devices’ performance, in terms of quantum efficiency and low dark current density, is considered a benchmark for other types of photodetectors. However, they require cryogenic operating temperature, which can lead to costly operations and maintenance. For alternatives, recent focuses have shifted to III-V material superlattice (SL)-based detectors capable of operating at room or near-room temperatures. InAs/GaSb SL-based detectors have been of interest due to their bandgap tuning capabilities and low noise. However, not many works have focused on the MWIR range. Our study will include quantum-optical simulations for determining the structural and optical characteristics of the proposed SL design. Device TCAD simulations will determine the baseline for dark current density and photocurrent spectrum. Experimental analysis will include device fabrication, and characterization measurements for dark current, photocurrent, capacitance-voltage and photocurrent spectrum.