"

Cookies ussage consent

Our site saves small pieces of text information (cookies) on your device in order to deliver better content and for statistical purposes. You can disable the usage of cookies by changing the settings of your browser. By browsing our site without changing the browser settings you grant us permission to store that information on your device.

Electrical properties of metallophthalocyanine thin films

R. DAIRA1,* , B. BOUDJEMA1, M. MORDJAOUI1, M. MEZIRI2

Affiliation

  1. Department of fundamental sciences, University August 20 1955 of Skikda, Road of El Hadaiek LP 26, Research laboratory physicochemistry of surfaces and interfaces of Skikda (LRPCSI), Algeria
  2. University of Annaba, Algeria

Abstract

Sandwich structures devices of type M1/MePc/M2 have been fabricated by successive vacuum deposition of M1 (Ohmic hole injections contact: Au), MePc (ZnPc, NiPc) and M2 (electrode with low work function: Al) thin films were thermally evaporate on glass substrates maintained at room temperatures under high vacuum (10-6torr).The DC electrical parameters and conduction processes in MePc (ФZnPc=4.7 ev) films were investigated by studying the J (V) characteristics for two contacts such Au (ФAu=5.1 ev) and Al (ФAl=4.28 ev). The charge transport phenomenon in the MePc films seems to depend highly on the electrode material and the temperature. The transport parameters, derived at room temperature are consistent with the values reported for some other authors on MePc’s. The results indicate that the electrical properties of ZnPc films are affected by oxygen molecules where play the role of acceptor dopant. The addition of O2 increases the conductivity of MePc thin films by several orders of magnitude. The measurement of the current according to the tension reveals the transition between Ohmic conduction for weak tensions applied (IΩ α V) and space charge limited current (ISCLC α Vm) for high tensions applied. Under forward bias and in the lower tension range structure exhibit an Ohmic conduction identified from current density-tension characteristics at room temperature. At high tension range, a transition from Ohmic comportment to space charge limited conduction (SCLC) has been observed. Also, a transition to exponential traps distribution mode is observed. The transport properties have been obtained from an analysis of the samples in the SCLC regime. The interaction of the charge injected with the localized states determines the behaviour of J (V)..

Keywords

Organic materials, Contact metal-organic semiconductors, SCLC current.

Citation

R. DAIRA, B. BOUDJEMA, M. MORDJAOUI, M. MEZIRI, Electrical properties of metallophthalocyanine thin films, Optoelectronics and Advanced Materials - Rapid Communications, 5, 2, February 2011, pp.167-171 (2011).

Submitted at: Jan. 19, 2011

Accepted at: Feb. 17, 2011