Investigation of current-voltage characteristics and current conduction mechanisms in composites of polyvinyl alcohol and bismuth oxide

Temperature dependent current-voltage (I-V) measurements of Au/Polyvinyl Alcohol + [Bi.sub.2][O.sub.3]/n-Si structure were conducted between 100 and 350 K for investigating the temperature dependence of I-V characteristics and current conduction mechanisms in the structure. Series resistance of the structure is calculated using Ohm's law and Cheungs' method. Ideality factor (n) and zero-bias barrier height ([Φ.sub.Bo]) were obtained considering thermionic emission theory. From 100 to 350 K, n changed from 32.1 to 3.54, and [Φ.sub.Bo] changed from 0.27 to 0.99 eV. Obtained temperature dependent values of n and [Φ.sub.Bo] suggested that thermionic emission is not the dominant current conduction mechanism. Therefore, Ln(I)-Ln(V) curves of the studied structure were plotted for investigating current conduction mechanisms in the structure and current flow is explained considering space charge limited current. Moreover, density of interface states ([D.sub.it]) in the structure were calculated and its temperature dependence was investigated such that [D.sub.it] values are reduced to the order of ~[10.sup.13] [eV.sup.-1] [cm.sup.-2] from ~[10.sup.14] [eV.sup.-1] [cm.sup.-2] with increasing temperature.
INTRODUCTION Over the last decade, various types of metal-insulator-semiconductor (MIS) structures have been investigated vastly by many researchers [1-11]. Metal-polymer-semiconductor (MPS) structures are used as an alternative to conventional MIS [...]