Skip to main content
Log in

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

  • Published:
Central European Journal of Physics

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.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Similar content being viewed by others

References

  1. R.A. Collins and M.K. Ellis: “Sensitivity of lead phthalocyanine thin films to ammonia and nitrogen dioxide”, Chemtronics, Vol. 5, (1991), pp. 93–95; R.A. Collins and K.A. Mohammed: “Gas sensitivity in some metal phthalocyanines”, J. Phys. D: Appl. Phys., Vol. 21, (1988), pp. 154-161.

    Google Scholar 

  2. C.L. Honeybourne and R.J. Ewen: “The enhancement of dark d.c. conductivity by gas adsorption on thin films of macrocyclic copper complexes”, J. Phys. Chem. Solids, Vol. 44, (1983), pp. 833–838.

    Article  Google Scholar 

  3. R.L. Van Ewyk, A.V. Chadwick and J.D. Wright: “Effects of oxygen, nitrogen dioxide and triflouforen on photoconductivity of perulene and phthalocyanines single crystals”, J. Chem. Soc. Faraday Trans., Vol. 1(77), (1981), pp. 73–79; D. Mayes, B. Remaki and G. Guillaud: “Space charge analysis in doped zinc phthalocyanine thin films”, Optical Materials, Vol. 9, (1998) pp. 240-244.

    Google Scholar 

  4. A.M. Saleh, A.O. Abu Hilal and R.D. Gould: “Investigation of electrical properties (ac and dc) of organic zinc phthalocyanine, ZnPc, semiconductor thin films”, Current Appl. Phys., Vol. 3, (2003), pp. 345–350.

    Article  Google Scholar 

  5. U. Drechsles, M. Pfaff and M. Hanack: “Synthesis of Novel functionalised zinc phthalocyanines applicable in photodynamic therapy”, Europ. J. Organic Chem., Vol. 1999, (1999), pp. 3411–3453.

    Google Scholar 

  6. E. Orti and J.L. Brades: “Electronic structure of metal-free phthalocyanine: A valence effective Hamiltonian theoretical study”, J. Chem. Phys., Vol. 89, (1988), pp. 1009–1016.

    Article  ADS  Google Scholar 

  7. R.D. Gould and A.K. Hassan: “A.c. electrical properties of thermally evaporated thin films of copper phthalocyanine”, Thin Solid Films, Vol. 223, (1992), pp. 334–340.

    Article  Google Scholar 

  8. S.A. James, A.K. Ray and S. Silver: “Dielectric and optical studies of sublimed MoOPc films”, Phys. Stat. Sol. A, Vol. 129, (1992), pp. 435–441.

    Google Scholar 

  9. T.G. Abdel-Malik, R.M. Abdel-Latif, M. El-Shbasy and M. Abdel-Hamid: “Compensation effect in the electrical process in phthalocyanines”, Indian J. Phys., Vol. 62A, (1988), pp. 17–23.

    Google Scholar 

  10. A.M. Saleh, R.D. Gould and A.K. Hassan: “Dependence of AC electrical parameters on Frequency and temperature in zinc phthalocyanine thin films” Phys. Stat. Sol. A), Vol. 139, (1993), pp. 379–389.

    Google Scholar 

  11. S.I. Shihub and R.D. Gould: “Frequency dependence of electronic conduction parameters in evaporated thin films of cobalt phthalocyanine”, Thin Solid Films, Vol. 254, (1995), pp. 187–193.

    Article  Google Scholar 

  12. N.M. Amar, A.M. Saleh and R.D. Gould: “Influence of temperature and frequency on the electrical parameters of thermally evaporated metal-free phthalocyanine H2Pc thin films”, Appl. Phys. A, Vol. 76, (2003) pp. 77–82.

    Article  ADS  Google Scholar 

  13. H.S. Nalwa and P. Vazudevan: “Dielectric properties of cobalt phthalocyanine”, J. Mater. Sci. Letters, Vol. 2, (1983) pp. 22–24.

    Article  Google Scholar 

  14. T.D. Anthopoulos and T.S. Shafai: “SCLS measurements in Nickel phthalocyanine thin films”, Phys. Stat. Sol. A, Vol. 181, (2000), pp. 569–574.

    Article  ADS  Google Scholar 

  15. M. Pfeiffer, A. Beyer, B. Plönnigs, A. Nollau, T. Fritz, K. Leo, D. Schlettwein, S. Hiller and D. Wöhrle: “Controlled p-doped of pigment layers by co-sublimation: Basic mechanisms and implications for their use in organic photovoltaic cells” Sol. Energy Mat. Sol. Cells, Vol. 63, (2000), pp. 83–89.

    Article  Google Scholar 

  16. W. Gao and A. Kahn: “Electronic structure and current injections in zinc phthalocyanine doped with tetrafluoro-teracyanoquinodimethene: Interface versus bulk effects”, Org. Electron., Vol. 3, (2002) pp. 53–63.

    Article  Google Scholar 

  17. K. Chuan Ho and Y. Ham Tsou: “Chemiresistors-type NO gas sensor based on nickel phthalocyanine thin films”, Sens. Actuators B, Vol. 77, (2001), pp. 253–259.

    Article  Google Scholar 

  18. R. Rellaa, A. Rizzob, A. Licciullic, P. Sicilianoa, L. Troisid and L. Vallic: “Tests in controlled atmosphere on new optical gas sensing layers based on TiO2/metal-phthalocyanine hybrid system”, Mat. Sci. Eng. C, Vol. 22, (2002), pp. 439–443.

    Article  Google Scholar 

  19. L. Hou, L. Cao, X. Li, H. Cui, D. Jiang, G. Zeng and S. Xi: “Study of ferric oxide nano-particles-tris-(2,4-di-tiamylyphenoxy)-(8-quinolinolyl) copper phthalocyanine composite LB film”, Thin Solid Films, Vol. 365, (2000), pp. 129–133.

    Article  Google Scholar 

  20. Z. Zhi-lin, J. Xue-yin, Z. Wen-quing, Z. Buxin and X. Shao-hong: “A white organic light emitting diode with improved stability”, J. Phys. D: Appl. Phys., Vol. 34, (2001), pp. 3083–3087.

    Article  ADS  Google Scholar 

  21. F.Z. Henari: “Optical switching in organometallic phthalocyanine”, J. Opt. A: Pure Appl. Opt., Vol. 3, (2001), pp. 188–190.

    Article  Google Scholar 

  22. H.R. Kerp and E.E. van Faassen: “Effects of oxygen on exciton transport in zinc phthalocyanine layers”, Chem. Phys. Lett., Vol. 332, (2002), pp. 5–12.

    Article  Google Scholar 

  23. B. Schöllorn, J.P. Germain, A. Pauly, C. Maleysoon and J.P. Blanc: “Influence of peripheral electron-withdrawing substituents on the conductivity of zinc phthalocyanine in the presence of gases. Part I: reducing gases”, Thin Solid Films, Vol. 326, (1998), pp. 245–250.

    Article  Google Scholar 

  24. J.P. Germain, A. Pauly, C. Maleysoon, J.P. Blanc and B. Schöllorn: “Influence of peripheral electron-withdrawing substituents on the conductivity of zinc phthalocyanine in the presence of gases. Part 2: Oxidizing gases”, Thin Solid Films, Vol. 333, (1998), pp. 235–239.

    Article  Google Scholar 

  25. L. Gao, X. Qian, L. Zhang and Y. Zhang: “Tetra-trifluoroethoxyl zinc phthalocyanine: potential photosensitizer for use in photodynamic therapy of cancer”, J. Photochem. Photobiol., Vol. 65, (2001), pp. 35–38.

    Article  Google Scholar 

  26. G.A. Rosquete-Pina, C. Zorrilla, S. Velumani, J. Arenas-Alatorre and J.A. Ascencio: “Theoretical and experimental analysis of ZnPc for its local ordering and electronic structure”, Appl. Phys. A: Materials Sci. & Processing, Vol. 79, (2004), pp. 1913–1918.

    ADS  Google Scholar 

  27. T.G. Abdel-Malik, A.M. Abdeen, H.M. El-Labany and A.A. Aly: “Bulk trapping in β-zinc phthalocyanine single crystals”, Phys. Stat. Sol. A, Vol. 72, (1982), pp. 99–104.

    Google Scholar 

  28. B. Boudjema, G. Guilland, M. Gamoudi, M. Maitrot, J.J. Andre, M. Martin and J. Simon: “Characterization of metallo-phthalocyanine-metal contacts: electrical properties in a large frequency range”, J. Appl. Phys., Vol. 56, (1984), pp. 2323–2329.

    Article  ADS  Google Scholar 

  29. A. Twarowski: “Temperature dependence of Schottky barrier capacitance in α-and β-zinc phthalocyanine”, J. Chem. Phys., Vol. 77, (1982), pp. 4698–4703; A. Twarowski: “Oxygen doping of zinc phthalocyanine thin films”, J. Chem. Phys., Vol. 77, (1982) pp. 5840-5846.

    Article  ADS  Google Scholar 

  30. R.A. Collins and K.A. Mohammed: “Phase behavior of cobalt, nickel and zinc phthalocyanines”, Thermochimica Acta, Vol. 109, (1987), pp. 397–402.

    Article  Google Scholar 

  31. M. Sakaguchi and M. Ohta: “Environmental effect on surface conductivity and the αβ phase transition of zinc phthalocyanine”, J. Sol. State Chem., Vol. 61, (1986) pp. 130–134.

    Article  ADS  Google Scholar 

  32. A.K. Mohesen, A.M. Saleh and R.D. Gould: “Conduction processes and dc electrical parameters of thermally evaporated iron phthalocyanine (FePc) thin films with aluminum electrodes”, Dirasat (Jordan University Res. Journal), Vol. 28, (2001), pp. 63–71.

    Google Scholar 

  33. F.S. Mahmood and R.D. Gould: “A.c. properties of ZnO thin films prepared by rf magnetron sputtering”, Thin Solid Films, Vol. 253, (1994), pp. 529–533.

    Article  ADS  Google Scholar 

  34. A. Goswami and A.P. Goswami: “Dielectric and optical properties of ZnS films”, Thin Solid Films, Vol. 16, (1973), pp. 175–185.

    Article  Google Scholar 

  35. Z.T. Al-Dahan and C.A. Hogarth: “Alternating current electrical properties of evaporated cerium dioxide films”, Int. J. Electronics, Vol. 63, (1987), pp. 573–585.

    Google Scholar 

  36. R.D. Gould and S.A. Awan: “Dielectric properties of AlNx thin films prepared by rf magnetron sputtering of Al using a N2/Ar sputtering gas mixture”, Thin Solid Films, Vol. 469-470, (2004), pp. 184–189.

    Article  Google Scholar 

  37. Yu.A. Vidadi, K.Sh. Kocharli, B.Sh. Barkhalov and S.A. Saredinov: “Alternating current investigation of copper phthalocyanine films in the presence of blocking contacts”, Phys. Stat. Sol. A, Vol. 34, (1976), pp. K77–K81.

    Google Scholar 

  38. J.G. Simmons, G.S. Nadkani and M.C. Lancaster: “Alternating current electrical properties of highly doped insulating films”, J. Appl. Phys., Vol. 41, (1970), pp. 538–544.

    Article  Google Scholar 

  39. A.K. Hassan and R.D. Gould: “The interpretation of current density-voltage and activation energy measurements on freshly prepared and heat-treated nickel phthalocyanine thin films”, Int. J. Electron., Vol. 74, (1993), pp. 59–65.

    Google Scholar 

  40. A.N. Blagodarov, E.L. Lutsenko and L.D. Rozenshtein: “Low-frequency conductivity of phthalocyanine films with unipolar injection”, Sov. Physics:-Solid State, Vol. 11, (1970), pp. 2747–2748.

    Google Scholar 

  41. Yu.A. Vidadi, L.D. Rozenshtein and E.A. Chistyakov: “Hopping and band conductivities in organic semiconductors”, Sov. Phys:-Solid State, Vol. 11, (1969), pp. 173–175; Yu.A. Vidadi, L.D. Rozenshtein and E.A. Chistyakov: “Two-layer film photocapacitor based on phthalocyanine without a metal”, Sov. Phys:-Semiconductor, Vol. 1, (1968), pp. 1049-1050.

    Google Scholar 

  42. S.R. Elliott: “A theory of ac conduction in chalcogenide glasses”, Phil. Mag., Vol. 36, (1977), pp. 1291–1304.

    Google Scholar 

  43. A.K. Jonscher: “Alternating current diagnostics of poorly conducting thin films”, Thin Solid Films, Vol. 36, (1976) pp. 1–20.

    Article  Google Scholar 

  44. J. Le Moigne and R. Evevn: “Spectroscopic properties and conductivity of thin films of partially reduced metallo-phthalocyanines”, J. Chem, Phys., Vol. 83, (1985), pp. 6472–6479.

    Article  ADS  Google Scholar 

  45. S.E. Harrison and K.H. Ludewig: “Conductivity and Crystal Phase Change in Phthalocyanines”, J. Chem. Phys., Vol. 45, (1966), pp. 343–348.

    Article  Google Scholar 

  46. A. Wilson, G.P. Rigby, J.D. Wright, S.C. Thorpe, T. Terui and Y. Maruyama: “Effects of heat treatment on chemical, morphological and NO2-sensing properties of lead phthalocyanine films”, J. Mater. Chem., Vol. 2, (1992), pp. 303–308.

    Article  Google Scholar 

  47. T.G. Abdel-Malik and G.A. Cox: “Charge transport in nickel phthalocyanine crystals: 1. Ohmic and space-charge-limited currents in vacuum ambient”, J. Phys. C: Solid State, Vol. 9, (1977), pp. 63–74.

    Article  ADS  Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

About this article

Cite this article

Kitaneh, R.M.L., Saleh, A.M. & Gould, R.D. Ac electrical parameters of Al-ZnPc-Al organic semiconducting films. centr.eur.j.phys. 4, 87–104 (2006). https://doi.org/10.1007/s11534-005-0008-4

Download citation

  • Received:

  • Accepted:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s11534-005-0008-4

Keywords

PACS (2006)

Navigation