Plasmonic metagrating-interlayer semiconductor (PMIS) structure for enhancing photodetection via hot-electron...

Area of Science:

• Optoelectronics
• Materials Science
• Nanotechnology

Background:

• Internal photoemission (hot-electron injection, HEJ) at metal-semiconductor (MS) Schottky interfaces shows potential for sub-bandgap optoelectronics.
• Enhancing photon-to-electron conversion efficiency is crucial for advancing HEJ-based devices.

Purpose of the Study:

• To introduce a novel plasmonic metagrating-interlayer-semiconductor (PMIS) structure.
• To significantly improve the efficiency of HEJ-based optoelectronic devices.

Main Methods:

• Utilizing an ultrathin 2D material interlayer in a metal-interlayer-semiconductor (MIS) heterojunction to lower the Schottky barrier via image force.
• Integrating the MIS heterojunction with a plasmonic metagrating for enhanced optical absorption.
• Tailoring the geometry and dimensions of the plasmonic metagrating for wavelength and polarization selectivity.

Main Results:

• Achieved high internal quantum efficiency (IQE) due to facilitated hot electron transport across the Schottky barrier.
• Enabled external quantum efficiency (EQE) to approach IQE through enhanced optical absorption via the plasmonic metagrating.
• Demonstrated wavelength- and polarization-selective photodetection capabilities.

Conclusions:

• The PMIS structure offers a significant enhancement in photon-to-electron conversion efficiency for HEJ-based devices.
• This technology provides a pathway toward bandgap-independent photodetection, energy harvesting, and photocatalysis.
• The tunable optical properties open avenues for advanced optoelectronic applications.