Insights into optical and photoelectrical properties of copper biphthalocyanine for efficient optoelectronic applications

Abstract

A novel copper biphthalocyanine (CuPc₂) compound was synthesized using a facile straightforward approach. Thermally deposited CuPc₂ thin films are prepared under vacuum at room temperature. The crystal and molecular structures of the deposited films relative to powder have been investigated using XRD and FTIR spectroscopy, respectively. The nanostructured CuPc₂ films, as visualized microscopically via FE-SEM, possess uniform surface morphology and low roughness. The optical properties of the deposited films are evaluated spectrophotometrically in the UV–vis–NIR region. The conventional Q and B-bands were identified with onset and fundamental energy gap of about 1.61, and 2.85 eV, respectively, and confirmed the α-molecular phase with small Urbach energy ∼43.5 meV. The dispersion characteristics were analyzed using the single oscillator and Sellmeier models. The optical dielectric, energy loss, and optical conductivity are deducted and interpreted. The nonlinear optical susceptibility, refractive index, and absorption coefficient were extracted and compared to many other metallophthalocyanines films. The present films exhibit exhibits abnormal PL emission spectrum along the visible region with white point CIE coordinates. Furthermore, the measured current-voltage relation of the designed Au/CuPc₂/p-Si/Al heterojunction is analyzed in detail. The ideality factor, reverse current, barrier height, series resistance shunt resistance, and interface state density are deduced. The photodetection features of the designed heterojunction are evaluated under different intensities (20–100) mW/cm². Fast and efficient responsive performance with high linearity is achieved by the present heterojunction; besides it offers the validity of usage under very low power consumptions (−0.05 V).