Dielectric Properties and AC Conductivity of Organic Films of Copper(II) 2,9,16,23-Tetra-tert-butyl-29H,31H- phthalocyanine

Abstract

Copper(II) 2,9,16,23-tetra-tert-butyl-29H,31H-phthalocyanine (CuTTBPc) thin films have been obtained using a physical vapor deposition technique. X-ray diffraction analysis confirmed their amorphous nature. The dielectric constant and electrical conductivity were measured over the frequency range from 50 Hz to 8 MHz and temperature range from 293 K to 393 K. The dependence of the dielectric relaxation spectra on frequency at different temperatures was measured and discussed. In addition, the spectral dynamics of both the real and imaginary parts of the complex electric modulus over a wide temperature range is explained. The activation energy of the relaxation process (DE M) was estimated to be 0.26 eV. Moreover, the dependence of the alternating current conductivity on both temperature and frequency was investigated. Additionally, the exponent (s) of the power law of conductivity versus temperature confirmed that the correlated barrier hopping (CBH) model is a successful and appropriate mechanism to explain the charge transportation inside CuTTBPc films. According to this model, the density of localized states N(E F) at room temperature and frequency of 500 kHz was evaluated to be 4.11 9 10 23 eV À1 cm À3. This high density of electron states indicates that CuTTBPc can be recommended as a candidate material for use in solar cells.

Influence of the Coordinated Ligand on the Optical and Electrical Properties in Titanium Phthalocyanine-Based Active Films for Photovoltaics

“…MPc molecules are particularly appealing because of their unique optical and electrical properties [ 7 , 8 , 9 ], allowing for their use in organic optoelectronic device applications and particularly in photovoltaic devices, due to the growing interest in solar energy conversion. The Pcs also acquire unique properties as a consequence of the metallic atom presence within the Pc, such as Cu and Zn [ 10 , 11 , 12 , 13 , 14 ].…”

“…However, related studies for the molecular state of TiOPc and TiCl 2 Pc are still rare and titanium phthalocyanine compounds have not received extensive research and study [ 18 ]. This results in a lack of optoelectronic properties’ correlation with their chemical structures, which is much less explored than other Pcs [ 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 ]. Due to that previously mentioned, the objective of this work is to present a comparative study between optical properties and the charge-carrying capability present in each one.…”

Morphology, structural properties, impedance spectroscopy, AC conductivity, and dielectric relaxation properties of boron subphthalocyanine chloride amorphous films

“…It is widely known that the amorphous structure strongly influences the improvement of the optical and electrical properties due to the localized states produced as a result of the imperfections through the material. These localized states play an essential role in reducing the width of the band gap energy and thus facilitate the hopping of the carrier charges between the neighboring sites [11]. Further, the amorphous nature supports cumulative layers' growth, creating a high-purity material.…”

“…´-computed to be 0.3 eV, indicating a low value of the barrier height, which in turn enhances the hopping charges between the neighboring sides of the potential barrier [11]. Among all MPcs compounds, boron subphthalocyanines chloride (B-subPcCl) is distinguished by its nonplanar configuration (cone-shaped).…”

Phase, AC conductivity and dielectric properties of Indeno[1,2-b]flourene-6,12 dione thin film as a function of frequency and temperature

“…This figure clarifies the linearly decreasing of lnσ AC with the rise of the reciprocal of temperature. This result implies that the thermal effect will activate the hopping charges between the potential barrier sides [28]. According to the Arrhenius equation, the thermal activation energy, ΔE, is practically calculated as follows [22]:…”