Electrical properties of Au/perylene-monoimide/p-Si Schottky diode

In this work, we have fabricated an Au/perylene-monoimide (PMI)/p-Si Schottky barrier diode. We have investigated how electrical and interface characteristics like current-voltage characteristics (I-V), ideality factor (n), barrier height (UB) and series resistance (Rs) of diode change with temperature over a wide range of 100-300 K. Detailed analysis on the electrical properties of structure is performed by assuming the standard thermionic emission (TE) model. Possible mechanisms such as image force lowering, generation- recombination processes and interface states which cause deviations of n values from the unity have been discussed. Cheung-Cheung method is also employed to analysis the current-voltage characteristics and a good agreement is observed between the results. It is shown that the electronic properties of Schottky diode are very sensitive to the modification of perylene-monoimide (PMI) interlayer organic material and also to the temperature. The ideality factor was found to decrease and the barrier height to increase with increasing temperature. The temperature dependence of barrier height shows that the Schottky barrier height is inhomogeneous in nature at the interface. Such inhomogeneous behavior was explained on the basis of thermionic emission mechanism by assuming the existence of a Gaussian distribution of barrier heights. © 2013 Elsevier B.V. All rights reserved.