Miniaturized and Hybrid p‐n Junction Diode Based on Iron Phthalocyanine/ZnO Nanostructured Thin Films Fabricated by Physical Deposition Techniques

Here we propose an innovative approach for the fabrication of hybrid p–n heterojunction diodes based on iron phthalocyanine (FePc) and zinc oxide (ZnO) on solid and flexible substrates using Al doped ZnO (AZO) as a transparent electrode. We combined transparent conductive thin films of ZnO with organic semiconductors represented by FePcs deposited by means of physical deposition, such as magnetron sputtering (MS), for undoped and doped ZnO thin films, and molecular beam epitaxy (MBE) for FePc deposition. The structural, optical and morphological properties of the fabricated hybrid diodes were assessed by X-ray diffraction (XRD), ellipsometric measurements, scanning tunneling microscopy (STM) and Raman techniques. Key electrical parameters such as current density and rectifying ratio (RR) were determined from the current density-voltage characteristic (J-V), which provided insights into the charge transport mechanisms and the organic/inorganic heterojunction interface. Moreover, by electrical impedance spectroscopy (EIS) measurements, we calculated the capacitance value of a p-n heterojunction and we assessed the equivalent circuit parameters of the heterojunction devices under equilibrium conditions. The results demonstrated the potential of combining inorganic transparent oxides with organic semiconductors for the development of flexible and transparent hybrid optoelectronic devices with improved efficiency.