Photoinduced Negative Differential Resistance at a Graphene/Silicon Interface: A Nonadiabatic Quantum Molecular...

Area of Science:

• Materials Science
• Quantum Physics
• Optoelectronics

Background:

• Oscillatory retinal neurons (ORNs) offer power-efficient, in-sensor cognitive image computing.
• ORNs rely on photoinduced negative differential resistance (NDR) at graphene/silicon interfaces for optical signal conversion.
• The precise optoelectronic mechanism underlying this NDR phenomenon remains unclear.

Purpose of the Study:

• To elucidate the fundamental optoelectronic mechanism responsible for NDR at graphene/silicon interfaces under illumination.
• To investigate the role of band alignment and charge transfer dynamics in generating NDR.
• To provide insights for the rational design of ORN devices for AI applications.

Main Methods:

• Nonadiabatic quantum molecular dynamics simulations were employed.
• Simulations analyzed the interplay of band alignment and charge transfer rates.
• The study examined carrier behavior at varying applied voltages under illumination.

Main Results:

• The interplay between band alignment and charge transfer rates at the graphene/silicon interface was shown to induce NDR.
• This NDR mechanism was observed under illumination and at varying applied voltages.
• Both intrinsic interface properties and extrinsic circuit factors contribute to ORN functionality.

Conclusions:

• The study clarifies the origin of NDR in graphene/silicon interfaces, crucial for ORN operation.
• Understanding this mechanism enables the rational design of ORN devices for edge AI.
• This research supports the development of advanced in-sensor computing technologies.