Optical characterizations and dielectric performance of 5,10,15,20-Tetrakis(pentafluorophenyl)-21H,23H-porphine palladium(II) for photodetector applications

Abstract

Photodetector application of organic-based device like porphine palladium (II) substitution, 5,10,15,20-Tetrakis (pentafluorophenyl)-21H,23H-porphine palladium (II), (TPPFT) thin films was investigated. A high quality and adherent films over various substrates were prepared using a low-cost spin coating method. The HR-TEM images confirm the nanofiber-like structure of TPPFT with a length of up to 2 μm and width in the range 20–30 nm. The X-ray diffraction pattern confirms that the deposited films were amorphous nature, which was further verified by the SAED pattern. The analysis of the absorption properties through the band edge revealed a direct allowed optical gap of about 2.87 eV. The oscillator and dispersion energies of 2.16 and 7.12 eV, respectively were extracted from the analysis of the dispersion curve using the typical single oscillator-based supported by the Wemple Didomenico relationship. . The measurements of the dielectric properties of TPPFT-based devices in a wide range of frequency up to 20 MHz under influence of DC-bias (−3 to 3 V) and temperature in the range 303–343 K the diodes indicate the effectiveness of the interface states at the device barriers. The real and imaginary parts of the impedance are found to be frequency dependence and interpreted via interfacial dipole time which is decreased with increasing the frequency within the desired bias range. The real and imaginary AC conductivities recorded a higher value of about 6 × 10−4 and 1.7 × 10−4 sm−1at 0.1 MHz under the bias of 3 V. The prepared junction device-based TPPFT presented a high rectification performance with a rectification ratio up to 103 at ±1 V. The responsivity, detectivity, and external quantum efficiency of the TPPFT-based devices under the illumination of 100 mW/cm2 was investigated under reverse bias and found to be 2.75 × 10−6 A/w, 9 × 10−9 Jones, and 7.8% at the bias of 1 V, respectively. The obtained results recommended that TPPFT-based devices can be utilized for the prospect photodetector application