Optical filter and electrical behavior of innovative Au/ZnPc/Si/Al organic heterojunction

Abstract

This research deals with the fabrication and properties of Au/ZnPc/Si organic heterojunction (OHJ). One broaden peak in X-ray diagram confirms the produced ZnPc phase. A (213)-oriented monoclinic crystal structure of ZnPc organic layer was confirmed by X-ray patterns having a grain size of 7.6 nm. Interesting profile of transmittance comprising peak and valley within the Vis and IR ranges yields to ZnPc layer an optical filter character. Optical filter properties of ZnPc organic layer are demonstrated. Throughout this study, the current-voltage (I–V) characteristics at room temperature under dark conditions are measured. The optical filter character of ZnPc layer is emphasized. Optical band energy gap of 2.8 eV is recorded. A wide p-type semiconductor based on organic ZnPc molecule is then identified. In order to determine some electrical parameters, Cheung and Norde approximations are used to extract the OHJ parameters under dark including ideality factor n, barrier height Φb, series resistance RS, and density of current. A Non-ideal behaviour of ZnPc/Si OHJ is revealed by the value of n which is greater than unity (n∼4.8). This fact is due to interface state distribution occurrence inside the device and high series resistance. We find the following values of series resistance and barrier height 0.69 eV, 7.9 kΩ. Conduction mechanism inside the ZnPc/Si OHJ are described and defined as SCLC the dominate mechanism.