Fabrication of High-Performance Visible-Blind Ultraviolet Photodetectors Using Electro-ionic Conducting Supramolecular Nanofibers

The detection of ultraviolet (UV) light is vital for various applications and also for its adverse effects
on human health. Organic UV photodetectors are gaining much attention in this scenario because
they possess properties such as high spectral selectivity and mechanical flexibility. However, the
achieved performance parameters are much more inferior than the inorganic photodetectors due to
the low charge carrier mobility in organic systems. In this work, we report the fabrication of a high-
performance visible-blind UV photodetector, using 1D supramolecular nanofibers made of coronene
tetracarboxylate (CS) and dodecyl methyl viologen (DMV) charge-transfer pairs. The nanofibers
exhibit high response mainly for UV wavelengths, the highest response being at ∼275 nm. The
fabricated photodetectors demonstrate desired features, such as high responsivity and detectivity,
high selectivity, low power consumption, and good mechanical flexibility, because of their unique
electro-ionic behavior and 1D structure. The device performance is shown to be improved by several
orders through the tweaking of both electronic and ionic conduction pathways while optimizing the
electrode material, external humidity, applied voltage bias, and by introducing additional ions. We
have achieved optimum responsivity and detectivity values of around 6265 A W –1 and 1.54 × 10 14
Jones, respectively, which stand out compared with the previous organic UV photodetector reports.
The present nanofiber system has great potential for integration in future generations of electronic
gadgets.


DOI: 10.1021/acsami.3c00716