Lateral cavity-enhanced guided mode resonance structures for mid-wave infrared photodetector pixels

Area of Science:

• Optics and Photonics
• Infrared Technology
• Semiconductor Devices

Background:

• Mid-wave infrared (MWIR) photodetectors are crucial for thermal imaging.
• Current MWIR photodetectors often face limitations in size, dark current, and operating temperature.
• Miniaturization is key for next-generation infrared sensing systems.

Purpose of the Study:

• To design and fabricate ultra-compact MWIR photodetector pixels.
• To achieve high external quantum efficiency (EQE) in a subwavelength pixel architecture.
• To enable room-temperature operation with low dark current for MWIR imaging.

Main Methods:

• Utilized a guided mode resonance (GMR) structure for light confinement.
• Employed a hybrid cavity-GMR approach for lateral mode confinement.
• Grew an all-epitaxial material stack for the photodetector absorber region.

Main Results:

• Achieved deep subwavelength thickness and lateral dimensions of approximately 2λo.
• Predicted external quantum efficiency (EQE) of approximately 50%.
• Demonstrated a design pathway for compact MWIR pixels.

Conclusions:

• The developed GMR-based photodetector pixels offer a path towards significantly smaller MWIR imaging systems.
• The design overcomes limitations of conventional MWIR detectors, enabling room-temperature operation and low dark current.
• This breakthrough facilitates the development of truly compact and efficient MWIR sensing technologies.