The electrical characteristics of metal–semiconductor hetero-structures with graphene oxide and perylenetetracarboxylic dianhydride interface

Abstract

In this study, we investigated the electrical properties of Al/p-Si, Al/GO/p-Si, Al/PTCDA/p-Si and Al/GO-PTCDA/p-Si structures were examined using current–voltage (I–V) and capacitance–voltage (C–V) characteristics at the room temperature. The main electrical parameters such as ideality factors (n), barrier heights (Φbo), saturation currents (I0), rectification ratios (RR) and series resistances (RS) were calculated separately for each of the four structure. The all contacts exhibited a rectification behavior with the different barrier height and ideality factor values. Experimental results indicate that the best Al/p-Si structure (reference structure) in respect of high value of RR (= 1.40 × 105) and low RS (= 17.5 ± 1.0), and same way, the Al/PTCDA/p-Si structure exhibits a behavior with the highest barrier height of 0.787 eV and lowest ideality factor value of 1.86. This situation can be attributed to the fact that the PTCDA organic interlayer increased the effective barrier height by influencing the space charge region of Si. Also, the interface state densities (NSS) as a function of energy distributions (ESS − EV) were obtained from the forward bias current–voltage measurements. The I–V analysis shows that use of different interface thin layers (GO, PTCDA, GO + PTCDA) has significant effect on electrical parameters of such devices.