EFFECTIVE CONDUCTIVITY OF CHEMICALLY DEPOSITED ZNO THIN-FILMS

Chemically deposited thin films have multiple applications. However, a s a result of their complex structure, their physical properties are v ery difficult to predict. In this paper, we use an effective medium ap proach to model these heterogeneous systems. We extend Thorpe's formul a for the effective electrical conductivity of elliptical holes random ly distributed in a matrix to a system composed of conducting ellipses in a conducting matrix. This extension is used to calculate the effec tive electrical conductivity of polycrystalline chemically deposited Z nO thin films. We compare experimental results obtained by two differe nt deposition methods: spray pyrolysis and successive ion layer adsorp tion and reaction (SILAR) reported here. We select the elliptical geom etric parameters from microstructural data. Good agreement between the experimental measurements and our calculation is obtained. In additio n, we present a new proof of the reciprocity theorem used to derive th e theoretical relation.