N-Type Superconductivity in an Organic Mott Insulator Induced by Light-Driven Electron-Doping

Area of Science:

• Materials Science
• Organic Electronics
• Superconductivity

Background:

• Self-assembled monolayers (SAMs) with interface dipoles influence device properties.
• Spiropyran derivatives in SAMs exhibit photochromism with significant dipole moment switching.
• Previous work showed light-induced p-type superconductivity using spiropyran-SAMs.

Purpose of the Study:

• To explore the converse of previous findings by inducing electron doping.
• To design a novel spiropyran monolayer for light-controlled electronic properties.
• To achieve light-induced n-type superconductivity in an organic Mott insulator.

Main Methods:

• Fabrication of a new spiropyran monolayer.
• Integration of the monolayer with an organic Mott insulator, κ-(BEDT-TTF)2Cu[N(CN)2]Br.
• Investigation of photoinduced doping and superconducting transitions via electrical measurements.

Main Results:

• Successful design of a spiropyran monolayer enabling light-induced electron doping.
• Observation of an accompanying n-type superconducting transition.
• Demonstration of controlled electric-field effects at device interfaces.

Conclusions:

• Photoactive SAMs can be engineered to control both magnitude and direction of photoinduced electric fields.
• This research opens new avenues for novel electronics based on photoresponsive interfaces.
• The findings pave the way for advanced organic electronic devices with tunable properties.