Determination of electrical properties of zinc phthalocyanine based heterojunction

In this study, a p-Si wafer with (100) orientation and 1-10 ?cm resistivity was used. 1,36x10-4 M solution of Zinc (2,3,9,10,16,17,23,24-Octakis(octyloxy)-29H,31H-phthalocyanine) (oc-ZnPc) which is one of the derivative of Zinc Phthalocyanine was prepared. Solution was prepared in methanol. A thin film of oc-ZnPc was spin coated on p-Si substrate. Aluminum was thermally evaporated on the oc-ZnPc thin film under high vacuum. Finally the Al/oc-ZnPc/p-Si structure was succeded.The current-voltage (I-V) and capacitance-voltage (C-V) measurements of Al/oc-ZnPc/p-Si structure were taken under dark at room temperature. The I-V measurements proved that the structure showed rectification property. Some basic diode properties like ideality factor and barrier height were calculated from lnI-V graph. Ideality factor and barrier height were found as 1.44 and 0.78 eV respectively. F(V)-V graph was plotted by using Norde functions. From the graph, the series resistance was calculated as 5.46 k?. C-V measurements were taken in the range of 0,2-5 MHz and it has been seen that the capacitance value decreased with increasing frequency.In addition I-V measurements of the Al/oc-ZnPc/p-Si were repeated under light which had intensity of 40-100 mW/cm2. It was observed that reverse bias current of the diode increased with the light intensity. Therefore, the structure showed fotodiode characteristic and it can be used in optoelectronic applications.