Surface topology, optical spectroscopic and electrical studies on boron subphthalocyanine chloride thin films
A.M. Hassanien
Abstract
Structural and optical spectroscopic analysis on boron subphthalocyanine chloride (SubPC-Cl) thin films were achieved. The structural analysis was performed using the attenuated total reflection Fourier transform infrared (ATR-FTIR) and Field emission scanning electron microscope (FESEM). Three optical bandgap transitions at 1.67, 1.96 and 2.18 eV were obtained from the diffuse reflectance spectra of powder SubPC-Cl. The absorption spectrum fitting (ASF) and derivation of absorption spectrum fitting (DASF) methods were applied to obtain the optical bandgap transitions of SubPC-Cl thin films. By applying ASF method, two optical bandgap transitions at 1.88 and 3.57 eV were estimated for the as-deposited thin film which slightly shift to lower wavelengths after annealing the film at 473 for 3 hours. Four emissions peaks at 245, 432, 450 and 480 nm with one shoulder at 407 nm were obtained from the photoluminescence spectroscopy of as-deposited SubPC-Cl thin films which slightly influenced by annealing the film at 473 K for 3 hours. The electrical conduction of SubPC-Cl thin film is through a thermally activated process with one activation energy. The estimated values of ΔE for the heating and cooling treatments are found to be 0.78 and 0.81 eV, respectively.