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
UV Detector
Suman Kundu, Subi J. George, and Giridhar U. Kulkarni
