Synthesis and characterization of O-PDI for futuristic optoelectronic and rectifier applications

Abstract

A non-fullerene organic semiconductor, N,N′-di(cis-9-octadecen-1-yl)perylene-3,4,9,10-tetracarboxylic diimide (O-PDI), was synthesized and characterized for its optoelectronic and rectifier applications. O-PDI, derived from the well-known dye perylene-3,4,9,10-tetracarboxylic dianhydride (PTCDA), was spectroscopically characterized for its structure and optical properties using NMR, Fourier-transform infrared (FT-IR), and MALDI-TOF. UV-Vis absorption and fluorescence spectroscopy techniques were employed to study its photophysical properties. Cyclic voltammograms of O-PDI were investigated, and the HOMO and LUMO energy levels of O-PDI were estimated to be −5.86 and −3.57 eV, respectively. Thermal properties were also studied by thermo-gravimetric analysis (TGA). Electrochemical analysis was performed to study its redox behaviour, and the lowest unoccupied molecular orbital and highest occupied molecular orbital energy levels were calculated. The electrical properties of the Al/P-C-Si/O-PDI/Ag device were investigated. The device's dark current–voltage (I–V) characteristics were measured at room temperature. Rectifying behaviour was observed in the device at room temperature with a rectification ratio of ∼3470@ ± 2 V. The device parameters, including the ideality factor, barrier height, series, and shunt resistances, were extracted using the conventional I–V characterization method. The parameters, such as cut-off voltage (∼0.79 V), reverse saturation current (I₀) (∼2.59 nA cm⁻²), barrier height (ϕ_b) (∼0.89 eV), ideality factor (n) (∼2.55), shunt resistance (R_sh) (∼24.21 MΩ), and series resistance (R_s) (∼2823 Ω), were determined at room temperature.