The effect of thickness of organic layer on electronic properties of Al/Rhodamine B/p-Si structure

Abstract

The effect of the thickness of a Rhodamine B film on the electronic properties of Al/Rhodamine B/p-Si structures has been investigated. Thin film of Rhodamine B organic compound was deposited on p-Si substrate as an interfacial layer by spin-coating technique. Currentvoltage (IV) and capacitancevoltage (CV) measurements of the Al/Rhodamine B/p-Si structure were performed at room temperature. The effect of the thickness of the Rhodamine B organic layer was investigated by evaluating electrical parameters, such as the barrier height, ideality factor, series resistance and interface state density. It is seen that the thickness of the Rhodamine B layer significantly affects the electrical properties of the Al/Rhodamine B/p-Si structures. Here, the fact that increasing the thickness modifies these parameters implies that there is likely a depletion region inside the Rhodamine B film. It has been concluded that the interfacial layer of organic compound Rhodamine B increases the effective barrier height by influencing the space-charge region of the Al/Rhodamine B/p-Si Schottky junction. Furthermore, it is seen that the values of the barrier height are significantly larger than those of conventional Al/p-Si Schottky diodes. © 2011 Elsevier Ltd. All rights reserved.