GeSn lateral p-i-n photodetector on insulating substrate

Area of Science:

• Optoelectronics
• Materials Science
• Semiconductor Devices

Background:

• Germanium-tin (GeSn) alloys are emerging materials for optoelectronic applications due to their tunable bandgap.
• Integration of GeSn with silicon photonics requires advanced substrate engineering.
• GeSn-on-insulator (GeSnOI) substrates offer a pathway for heterogeneous integration.

Purpose of the Study:

• To experimentally demonstrate the first lateral p-i-n photodetector fabricated on a novel GeSnOI substrate.
• To evaluate the performance characteristics of the GeSnOI photodetector at room temperature.
• To assess the detection capabilities of the device for infrared wavelengths.

Main Methods:

• Fabrication of GeSnOI substrate using direct wafer bonding and layer transfer techniques.
• Fabrication of lateral p-i-n photodetectors on the GeSnOI substrate.
• Electrical and optical characterization of the fabricated photodetectors.

Main Results:

• Successful demonstration of a lateral p-i-n photodetector on a GeSnOI substrate.
• The photodetector exhibited well-behaved diode characteristics with a high on/off current ratio (~4 orders of magnitude at ± 1 V) at room temperature.
• Achieved a cutoff detection wavelength beyond 2 µm with a photoresponsivity of 0.016 A/W at 2004 nm.

Conclusions:

• The developed GeSnOI substrate is a promising platform for large-scale integration of nano-electronic and photonic devices.
• The GeSnOI photodetector demonstrates effective infrared detection capabilities, suitable for various sensing applications.
• This work paves the way for advanced GeSn-based optoelectronic integrated circuits.