Optical and electrical properties of 1,3,5-triphenylbenzene (TPB) thin film for optoelectronic devices

Abstract

This study examined a novel Triphenylbenzene (TPB) thin film deposited using a spin coating to explore its optical and electrochemical properties. From the optical study made using UV–Vis absorption and Photoluminescence (PL) spectroscopy, a narrow absorption peak at 305 nm occurs due to π→π* electronic transition with an optical bandgap of 3.81 eV. The emission properties of the thin film were examined in the excitation range 312 nm–340 nm with maximum emission at 360 nm for excitation wavelength 318 nm giving blue emission. For electrochemical analysis, the Cyclic voltammograms (CV) were recorded at various scan rates (40 mV/s to 120 mV/s) to show the reversibility of the redox reaction. The peak anodic (Ipa) and cathodic ((Ipc) currents were studied along with their capacitances Cp at various scan rates. The Randle Sevick equation was studied to understand the diffusive-controlled behaviour of the thin film. From optical and electrical analysis, TPB is found to be a suitable candidate for optoelectronic devices, such as Organic light-emitting diodes (OLEDs) and Organic Solar cells.