Investigation of the Structural, Optical, and Electrical Properties of ZnO/4‐Amino‐2‐Methylquinoline p–n Heterojunction by Spin‐Coating Method

Abstract

A p–n heterojunction diode is fabricated using a p‐type 4‐amino‐2‐methylquinoline (C10H10N2) on an n‐type ZnO film and its structural, optical, and electrical properties are investigated. First, a ZnO thin film is prepared on an ITO substrate by spin coating. Subsequently, this ZnO film is coated with a C10H10N2 film using the same method. X‐ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), UV–vis spectroscopy, and current–voltage measurements are carried out on the prepared films. According to the XRD result, sharp peaks at 320.081, 340.488, and 360.548 are observed in the hexagonal phase of ZnO. At these angles, grain sizes of 15.308, 15.179, and 13.715 nm are calculated. The absorption peaks of electronic transitions π→π*, n→π*, and d→d* in the ZnO/C10H10N2 heterojunction film are observed. From the IV diagram, it can be seen that the heterojunction structure has a diode characteristic. From the IV data, the rectification factor is calculated to be 6.59 and its graph is drawn. With the Cheung method, ideality factor (n) = 2.87, series resistance (RS) = 1 MΩ, and shunt resistance (RSh) = 5 kΩ are found.