Polyaniline-Crystalline Rubrene nanosystem Synthesis by One-step Plasma Based Route: Application in Optoelectronics by Plasmonic Functionalization

Crystallization of organic small molecule Rubrene is a tedious job when conventional route such as vapour phase deposition is adopted for its synthesis. The amazingly high conductivity exhibited by crystalline Rubrene is the reason behind researchers looking for easy and sustainable alternate routes for its synthesis. In this report, a single step plasma based synthetic route of Rubrene is illustrated through which we have successfully synthesized Rubrene in crystalline form along with polyaniline thin film. In addition to the synthesis of plasma polymerized aniline (PPA)-crystalline Rubrene (CRB) thin film, we further incorporated magnetron sputtered gold nanoparticles (Au NPs) in it and integrated this PPA-CRB/Au structure in bilayer optoelectronic device architecture. The Au incorporated device exhibits enhanced photocurrent, responsivity and detectivity over the broadband wavelength range UV-visible-near infrared attributed to the increased absorption in the visible region due to Rubrene and the plasmon absorption of Au in the NIR region. Moreover, both the devices can operate in self-powered mode and show very fast response to the switching light signal of 1 Hz frequency. This study thus throws light on removing the hurdles of crystalline Rubrene synthesis and its application in optoelectronics.