14 GHz Schottky Diodes Using a p-Doped Organic Polymer

Area of Science:

• Organic electronics
• Semiconductor devices
• Radio frequency (RF) engineering

Background:

• Organic semiconductors face limitations in carrier mobility and parasitic resistance/capacitance for RF applications.
• Conventional organic Schottky diodes struggle to meet the demands of emerging RF electronics.

Purpose of the Study:

• To overcome limitations in organic Schottky diodes for RF applications.
• To demonstrate RF Schottky diodes operating in the 5G frequency spectrum.
• To investigate the impact of p-doping on diode performance.

Main Methods:

• Fabrication of self-aligned asymmetric nanogap electrodes (≈25 nm) using adhesion lithography.
• Utilizing a high hole mobility polymer, C16 IDT-BT.
• Studying the effect of p-doping with C60F48 on device characteristics.

Main Results:

• Pristine C16 IDT-BT diodes achieved intrinsic and extrinsic cutoff frequencies (fC) of >100 GHz and 6 GHz.
• Nanogap architecture and low junction capacitance (<2 pF) contribute to high performance.
• Doping improved performance to intrinsic and extrinsic fC of >100 GHz and ≈14 GHz, with a tenfold increase in RF rectifier output voltage.

Conclusions:

• The planar nanogap architecture is crucial for high-frequency organic Schottky diodes.
• Doping significantly enhances the performance of these organic RF diodes.
• This work enables the use of organic Schottky diodes in future large-area RF electronics.