Light absorption enhancement in Ge nanomembrane and its optoelectronic application

Area of Science:

• Materials Science
• Optoelectronics
• Nanotechnology

Background:

• Germanium (Ge) nanomembranes (NM) are promising materials for optoelectronic applications.
• Understanding light absorption properties is critical for optimizing device performance.
• Structural defects can significantly influence material properties.

Purpose of the Study:

• To analyze the light absorption properties of hydrogen (H)-incorporated Ge nanomembranes (NM) in the near-infrared (NIR) wavelength range.
• To investigate the impact of structural defects and H incorporation on Ge's light absorption coefficient.
• To demonstrate the potential of H-incorporated Ge in photodetector applications.

Main Methods:

• Fabrication of H-incorporated Ge nanomembranes.
• Optical characterization of light absorption in the NIR spectrum (1000-1600 nm).
• Fabrication and testing of metal-semiconductor-metal (MSM) photodetectors using H-incorporated Ge on Ge-on-insulator (GeOI).

Main Results:

• H-incorporated Ge layers exhibit a significantly higher light absorption coefficient (up to 10 times) compared to bulk Ge in the 1000-1600 nm range.
• Structural defects in Ge NM contribute to the enhanced light absorption.
• Released Ge NM with H incorporation showed increased light absorption compared to bulk Ge.
• Successful demonstration of MSM photodetectors utilizing H-incorporated Ge on GeOI.

Conclusions:

• Hydrogen incorporation and structural defects in Ge nanomembranes substantially enhance near-infrared light absorption.
• These findings highlight the potential of H-incorporated Ge for high-performance optoelectronic devices.
• The developed H-incorporated Ge nanomembranes are suitable for advanced photodetector applications.