Room-Temperature (RT) Extended Short-Wave Infrared (e-SWIR) Avalanche Photodiode (APD) with a 2.6 µm Cutoff...

Area of Science:

• Optoelectronics
• Semiconductor Physics
• Materials Science

Background:

• High-sensitivity infrared photodetectors are crucial for various sensing and imaging applications.
• Existing technologies often require cryogenic cooling, limiting their practical use.

Purpose of the Study:

• To develop extended short-wave infrared (e-SWIR) avalanche photodiodes (APDs) that operate effectively at room temperature (RT).
• To extend the detection wavelength of APDs for enhanced infrared sensing capabilities.

Main Methods:

• Utilized In_0.3Ga_0.7As_0.25Sb_0.75/GaSb heterostructures with higher indium composition for extended wavelength detection.
• Employed lattice-matched heterostructures on GaSb substrates to ensure high material quality.
• Characterized device performance including detection spectrum, noise current, multiplication gain, and photoresponsivity at RT.

Main Results:

• Successfully extended the detection cut-off wavelength to 2.6 µm at RT, verified by FTIR measurements.
• Achieved a high multiplication gain (M~190) at a low bias (-2.5 V) with a 2.3 µm DFB laser.
• Demonstrated high photoresponsivity (R>140 A/W) at RT and low bias.
• Identified noise current as shot noise-limited at RT.

Conclusions:

• Developed room-temperature operating e-SWIR APDs using In_0.3Ga_0.7As_0.25Sb_0.75/GaSb heterostructures.
• The high internal gain and RT operation offer enabling technology for e-SWIR sensing and imaging.
• These APDs significantly reduce size, weight, and power consumption (SWaP) for infrared applications.