Correlation between induced changes in the structural properties of nanostructured boron subphthalocyanine chloride thin films and their linear and nonlinear optical properties

摘要

Metal phthalocyanines (MPcs) are widely used in optoelectronic applications thanks to their high absorption in the visible region, durability, tunability and chemical stability. This paper aims to address the induced changes in the structure of boron subphthalocyanine chloride (BsubPc-Cl) thin films - before and after annealing processes - and correlate these changes with their linear and nonlinear optical properties. The BsubPc-Cl thin films have been characterized via the differential scanning calorimeter (DSC), X-ray diffraction (XRD), atomic force microscope (AFM) and UV-Vis.-IR spectroscopy. The DSC thermograph curve through a wide range of temperatures (20-340 degrees C) has proved the thermal stability of BsubPc-Cl films. The XRD calculations have revealed the nanostructure of the films. In addition, the particle size is a temperature dependent and it increases with increasing annealing temperature. In context, the AFM images have declared that the roughness of the films' surfaces increases with increasing annealing temperature. The absorbance spectra of BsubPc-Cl thin films have elucidated two peaks at lambda = 300 and 603 nrn which are assigned to B and Q bands, respectively. Further, the pristine film had a peak centered at 1550nm which underwent a blue shift to 1185 nm due to annealing. The BsubPc-Cl films have showed high third-order nonlinear susceptibility chi(3 )= 8 x 10(-12) esu. Moreover, chi(3) values have increased between visible and NIR regions which may suggest employing BsubPc-Cl as an optical switch.