Enhanced self-powered ion-modulated photodetector based on an asymmetric composite structure of superionic conductor...

Area of Science:

• Materials Science
• Condensed Matter Physics
• Device Engineering

Background:

• Traditional self-powered devices exhibit performance limitations due to inherent parameter trade-offs.
• Graphene-based photodetectors offer potential but often require external bias or face similar trade-offs.

Purpose of the Study:

• To propose and fabricate a novel ion-modulation self-powered photodetector.
• To overcome the performance parameter trade-offs in conventional self-powered devices.
• To investigate the mechanism of photocurrent generation in a graphene-superionic conductor heterostructure.

Main Methods:

• Fabrication of a photodetector by depositing superionic conductor RbAg4I5 on monolayer graphene.
• Formation of a graphene homojunction at the asymmetric structure interface.
• Characterization of photoresponse under ultraviolet and visible light irradiation without applied bias.

Main Results:

• Successful formation of a graphene homojunction due to ion-electron bound states.
• Photocurrent generation dominated by the dissociation of bound states under illumination.
• Achieved responsivity of 20 mA/W and response speed of 700 µs for UV-Vis light without bias.
• Demonstrated superior performance compared to existing graphene-based self-powered devices.

Conclusions:

• The ion-modulation photodetector effectively overcomes traditional performance trade-offs.
• A semi-quantitative model confirms good consistency with experimental results.
• This work provides a new avenue for developing high-performance self-powered devices using superionic materials.