Monolithic PbSe/Ge/Si Heteroepitaxial Architecture for Uncooled Dual-Band Infrared Detection

Area of Science:

• Materials Science
• Optoelectronics
• Semiconductor Physics

Background:

• Developing uncooled dual-band (near-infrared/mid-wave infrared) detectors is challenging due to limitations in heteroepitaxial growth and material property control.
• Such detectors are crucial for applications like quantum communication and thermal analysis.

Purpose of the Study:

• To demonstrate a novel PbSe/Ge/Si heterostructure for NIR-MIR dual-band detection.
• To overcome challenges in heteroepitaxial growth for advanced detector applications.

Main Methods:

• Utilized a substrate surface selenization technique to create the PbSe/Ge/Si heterostructure.
• Performed laser illumination tests to measure room-temperature responsivity at NIR and MIR wavelengths.
• Conducted blackbody testing to determine peak detectivities (D*) at specific infrared wavelengths.

Main Results:

• Achieved room-temperature responsivity of 0.43 A·W⁻¹ at 2700 nm (NIR) and 0.7 A·W⁻¹ at 1550 nm (NIR).
• Measured peak detectivities of 4.2 × 10⁹ cm·Hz¹/²·W⁻¹ at 3.7 μm (MIR) and 3.5 × 10⁹ cm·Hz¹/²·W⁻¹ at 1.2 μm (NIR).
• Theoretical optimization suggests a back-to-back n-i-p-i-n architecture could significantly enhance D*.

Conclusions:

• The demonstrated PbSe/Ge/Si heterostructure offers room-temperature dual-band sensitivity for NIR and MIR detection.
• This work is a significant step towards compact multispectral systems for field-deployable quantum communication and portable thermal analytics.
• Further optimization could lead to substantially improved detector performance.