Frequency dependence of electronic conduction parameters in evaporated thin films of cobalt phthalocyanine

Shihub, S.I.; Gould, R.D.

doi:10.1016/0040-6090(94)06240-l

Cited by 59 publications

(31 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…3 displays the variation of capacitance (A) and loss tangent (B) with temperature at various constant frequencies. The novel feature of the present study is that the capacitance and loss tangent of Al-ZnPcAl appear to show a steady variation with temperature above 270 K. Similar performance was observed in this laboratory for other metal-phthalocyanines such as in a thermally evaporated CuPc [7], Au-ZnPc-Au [10], CoPc [11], and in FePc [32] thin films. Generally, both C and tan δ increase at temperatures above room temperature and low frequencies while at low temperatures and high frequencies both are almost constant.…”

Section: Temperature Dependencesupporting

confidence: 61%

“…At low frequencies and all temperatures, a strong dependence is observed, while at higher frequencies a moderate dependence is apparent. Such behavior have been found previously in other phthalocyanine thin films like for example CuPc [7], Au-ZnPc-Au [10], CoPc [11], H 2 Pc [12] and in FePc [32], and also in CoPc pellets [13]. In addition, some non-organic compounds like ZnO [33], ZnS [34] and CeO 2 [35] showed resembling behavior.…”

Section: Frequency Dependencementioning

confidence: 49%

“…5A and B may be fitted to a relation of the form: where A is a complex constant, ω is the angular frequency and the index s is determined from the slopes of the curves. Generally, the frequency dependence of ac conductivity of other phthalocyanine compounds has similar performance [7,[9][10][11][12]. In contrary, Blagodarov et al [40] noticed that the conductivity of metal phthalocyanine thin films was frequency independent when an external voltage was applied to the films.…”

Section: Variation Of Ac Conductivity With Frequencymentioning

confidence: 99%

“…The position of the minimum of tan δ as predicted by Eq. (5) is qualitatively observed, in that the minimum for the 193 K is at lower frequency than those for 253 K and 274 K. Nevertheless, no minimum was observed in tan δ for some other phthalocyanine samples as CuPc [7], ZnPc [10], CoPc [11], H 2 Pc [12] and FePc [32], while in MoPc [8] a broad minimum was observed followed by maximum at about 1.9×10…”

Section: Frequency Dependencementioning

confidence: 99%

“…. ) have attracted several research groups in the last decades [7][8][9][10][11][12][13][14]. In addition, the technological applications of these compounds have also received the attention of many more research groups.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Ac electrical parameters of Al-ZnPc-Al organic semiconducting films

Kitaneh¹,

Saleh²,

Gould

2006

Open Physics

View full text Add to dashboard Cite

Abstract:The ac electrical parameters of thermally evaporated zinc phthalocyanine, ZnPc, semiconducting thin films was measured in the temperature range of 180 -390 K and frequency between 0.1 and 20 kHz. Aluminum electrode contacts were utilized to sandwich the organic ZnPc semiconducting films. Capacitance and loss tangent decreased rapidly with frequency at high temperatures, but at lower temperatures a weak variation is observed. An equivalent circuit model assuming ohmic contacts could qualitatively and successfully explains capacitance and loss tangent behavior. The ac conductivity showed strong dependence on both temperature and frequency depending on the relevant temperature and frequency range under consideration. Ac conductivity σ (ω) is found to vary with ω, as ω s with the index s ≤ 1.35 suggesting a dominant hopping conduction process at low temperatures (< 250 K) and high frequency. The conductivity of some samples did not increase monotonically with temperature. This behavior was attributed to oxygen exhaustion of the sample as its temperature is increased. The ac conductivity behavior at low temperatures of ZnPc films could be described well by Elliott model assuming hopping of charge carriers between localized sites.

show abstract

Section: Temperature Dependencesupporting

confidence: 61%

Section: Frequency Dependencementioning

confidence: 49%

Section: Variation Of Ac Conductivity With Frequencymentioning

confidence: 99%

Section: Frequency Dependencementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Ac electrical parameters of Al-ZnPc-Al organic semiconducting films

Kitaneh¹,

Saleh²,

Gould

2006

Open Physics

View full text Add to dashboard Cite

show abstract

Dielectric properties of new fully conjugated 2H‐ and metal‐pyrazinoporphyrazine network polymers

Abdel-Razik

El-Sayed

Hassen

2011

J of Applied Polymer Sci

View full text Add to dashboard Cite

2,7-Di-tert-butylpyrene was oxidized to 2,7-di-tert-butylpyrene-4,5,9,10-tetraone. The latter through condensation reaction with vicinal diamine such as diaminomaleodinitrile afforded heterocyclic monomer, 2,7-di-tert-butyl pyrene [4,5][9,10]bis(2,3-pyrazine-5,6-dinitrile), which was cyclotetramerized to the corresponding 2H-and metal-pyrazinoporphyrazine-based network polymers (2H-PyzPz and M-PyzPz, M ¼ Co, Ni, Zn, or Cu). Elemental analytical results, Infrared, and NMR spectral data of the new prepared molecules are consistent with their assigned formulations. Molecular masses and metal contents of the synthesized polymers proved to be of high molecular masses, which confirm the efficiency of tetramerization polymerization and complexation reactions. Dielectric permittivity, e 0 , loss tangent, tan d, and ac conductivity, rac(x), of 2H-PyzPz and M-PyzPz films were studied as a function of temperature and frequency. It was found that dielectric permittivity, e 0 , decreases with the increase of frequency and increases with the increase in temperature. Ac conductivity, rac(x), is found to vary as Bxs and the frequency exponent, s, is less than unity around room temperature indicating a dominant hopping process. On the other hand, rac(T) of all samples is thermally activated with low activation energies.

show abstract

Thin Films

Gould¹

2006

Springer Handbook of Electronic and Photonic Materials

View full text Add to dashboard Cite

Frequency dependence of electronic conduction parameters in evaporated thin films of cobalt phthalocyanine

Cited by 59 publications

References 27 publications

Ac electrical parameters of Al-ZnPc-Al organic semiconducting films

Ac electrical parameters of Al-ZnPc-Al organic semiconducting films

Dielectric properties of new fully conjugated 2H‐ and metal‐pyrazinoporphyrazine network polymers

Thin Films

Contact Info

Product

Resources

About