Effects of Heat Treatments on the Properties of Copper Phthalocyanine Films Deposited by Glow-Discharge-Induced Sublimation

Abstract

Copper phthalocyanine films have been deposited by glow-discharge-induced sublimation. The films have undergone postdeposition heat treatments in air at 250 and 290 °C for different times, ranging from 30 min to 14 h. The properties of as-deposited and heated films have been investigated by different techniques in order to determine the effects of heat treatments on the film properties. Fourier transform infrared analysis and UV-visible optical absorption analysis point out a gradual evolution of the film structure from a mixture of R and β polymorphs to the only β polymorph in the sample heated at 290 °C for 14 h. A pronounced decrease of carbon and nitrogen atomic percentages against an oxygen increase in the heated films are shown by ion beam analyses (Rutherford backscattering spectrometry and nuclear reaction analysis) and X-ray photoelectron spectroscopy (XPS). X-ray absorption spectroscopy and XPS indicate that part of the copper phthalocyanine molecules decompose during heat treatments and the formation of copper oxide takes place. The replacement of copper phthalocyanine by copper oxide in the heated films accounts for the change of their surface electrical conductance and of their electrical response to NO 2 .

Interaction of Copper Phthalocyanine with Nitrogen Dioxide and Ammonia Investigation Using X-ray Absorption Spectroscopy and Chemiresistive Gas Measurements

“…5 eV shift from the elemental Cu K-edge with an energy of 8979 eV shows the +2 oxidation state of the CuPc layer. , It is noted that the rising edge, ca. 8984 eV, of pristine CuPc layer here is similar to the reported value of CuPc layer that was deposited using glow discharge sublimation method . In Figure , two main peaks labeled as peak A and peak B were obtained and can be correlated with 1s → 4p transition.…”

“…8984 eV, of pristine CuPc layer here is similar to the reported value of CuPc layer that was deposited using glow discharge sublimation method. 49 In Figure 6, two main peaks labeled as peak A and peak B were obtained and can be correlated with 1s → 4p transition. Furthermore, details on the distortion from ligands bonded on axial position can be derived from peak A.…”

Growth, characterization and sensing capabilities of 5,10,15,20-meso-tetraphenyl iron (III) porphyrin chloride films obtained by means of a novel plasma-based deposition technique

“…As regards the Q band zone, it is possible to note that differently from the solution spectrum, both GDS and SPIN samples show a two peak structure between 500 and 600 nm. These features are attributed to hyper spectra [23][24][25] due to the metal to ligand charge transfer and arise from the considerable mixing of the metal d orbitals with the LUMO of the porphyrin.…”

“…GDS has in past demonstrated to be a suitable technique for the deposition of a wide range of organic materials going from polymers to fluorescent dyes [23][24][25], moreover; GDS has recently showed to be a promising technique for the production of organic films for gas sensing applications, allowing to produce organic films characterized both by high purity and by a large surface area to volume ratio [26][27][28]. Fe(TPP)Cl films have been also deposited by means of spin coating (SPIN) technique, which represents a standard technique for the production of porphyrin films for gas sensing applications [20,29], in order to get a reference for evaluating the sensing capabilities of GDS films.…”

Room temperature detection of amine vapours using copper phthalocyanine based thin films

“…Until now, various techniques such as glow discharge induced sublimation, vacuum deposition, molecular beam epitaxy, spin coating and Langmuir–Blodgett technique have been employed to fabricate phthalocyanine based gas sensors 19, 27, 34, 35. Among them, spin coating is a low cost, fast and reproducible technique for fabricating uniform films.…”