Electrical Properties of Pt/n-Ge Schottky Contact Modified Using Copper Phthalocyanine (CuPc) Interlayer

We investigated the electrical properties and reverse leakage mechanisms of Pt/n-Ge Schottky contacts with copper phthalocyanine (CuPc) as an interlayer. The current-voltage (I-V) and capacitance-voltage (C-V) characteristics of the Schottky contacts were used to evaluate Schottky barrier parameters such as ideality factor, barrier height, and series resistance. The barrier heights and ideality factors measured from the forward bias I-V characteristics were found to be 0.50 eV and 1.06 for Pt/n-Ge Schottky contact, and 0.58 eV and 1.31 for Pt/CuPc/n-Ge Schottky contact, respectively. Cheung method was used to measure the series resistances of the Schottky contacts, and the consistency was checked using the Norde method. The reverse leakage conduction mechanism of the Schottky contacts was investigated. Pt/CuPc/n-Ge Schottky contacts showed a transition from Schottky emission to Poole-Frenkel emission at a higher bias range. This could be associated with the high density of structural defects or traps associated with the organic material. (C) 2011 The Electrochemical Society. [DOI: 10.1149/2.041201jes]