Acid vapor-induced enhanced electrical current rectification in phenothiazine-based electronic devices.

Area of Science:

• Molecular electronics
• Materials science
• Organic electronics

Background:

• Engineering molecular junctions for tunable electronic functions is crucial for advancing molecular-scale electronics.
• Phenothiazine-based molecular junctions (MJs) offer potential for novel electronic functionalities.

Purpose of the Study:

• To demonstrate external stimuli-responsive enhanced electrical current rectification in phenothiazine-based molecular junctions.
• To investigate the mechanism behind the enhanced rectification and its reversibility.

Main Methods:

• Fabrication of vertically stacked molecular junctions (p+-Si/R158 nm/ITO).
• Exposure to acid vapor and subsequent electrical characterization (current rectification, electrical impedance spectra).
• Investigation of molecular orbital alignment using theoretical principles.

Main Results:

• A nearly 530% enhancement in the electrical current rectification ratio (RR) was observed upon 60-second acid vapor exposure.
• The electronic functions were partially reversible upon exposure to triethylamine vapor.
• Acid vapor exposure leads to cation radical formation, altering molecular orbital energy levels (LUMO) relative to electrode Fermi level, enabling rectification.

Conclusions:

• Phenothiazine-based molecular junctions exhibit significant, reversible, acid-vapor-induced diode functionality.
• This work presents a method for high-yield device fabrication (∼86%) for transformable electronic functions.
• The findings pave the way for developing molecular-scale devices with tunable electronic properties responsive to chemical stimuli.