Speaker
Description
Fermi level pinning at metal-organic interfaces typically restricts
post-fabrication tuning of Schottky barrier diodes (SBDs), limiting
their optimization for flexible optoelectronic applications. We
demonstrate that swift heavy ion (SHI) irradiation provides a viable
nanoscale engineering approach to systematically modify interfacial
states and barrier characteristics in ITO/PANI-graphene/Al Schottky
diodes. Devices were irradiated with 36 MeV Cu³⁺ ions at fluences
ranging from 5.4×10¹² to 6.4×10¹³ ions/cm² under high vacuum at
room temperature. Current-voltage characterization revealed that
unirradiated PANI devices exhibited an ideality factor of 3.8, barrier
height of 0.885 eV, and rectification ratio of 98.6. With increasing ion fluence, both barrier height and rectification ratio decreased
systematically, while forward and reverse currents increased,
accompanied by reduced turn-on voltage. Analysis of bias dependent ideality factors showed that the interface state density
(Nss) increased exponentially and shifted toward the valence band
edge with increasing dose, indicating enhanced defect populations
at the metal-organic junction. Differential resistance measurements
confirmed that shunt resistance decreased sharply with fluence,
consistent with enhanced charge injection. At higher bias voltages,
irradiated devices transitioned from trap-limited to trap-free spacecharge-limited conduction (SCLC), with current-voltage slopes
approaching 2, consistent with Child's law and indicative of carrier
detrapping. These results establish SHI irradiation as a powerful
post-fabrication tool for controlled tuning of barrier properties in
organic Schottky devices, with implications for Schottky-type
photodetectors and low-power rectifying elements in flexible
electronics.
| Apply for student award at which level: | None |
|---|---|
| Consent on use of personal information: Abstract Submission | Yes, I ACCEPT |