Analysis of Electrical Characteristics of N-Doped TiO2 and Si Heterojunction Diodes

Heterojunction photodiodes play a crucial role in various industries and daily life. They find application in fields such as photoelectric detection, aerospace, and intelligent manufacturing. In this study, we employed a series of growth processes, including physical vapor deposition techniques such as magnetron sputtering, high-temperature annealing, and hydrothermal growth, to fabricate N-doped TiO2 heterojunction diode devices with Si as a substrate material. The surface of the device exhibited a columnar array structure with rutile phase TiO2. Additionally, the doping of N element led to the bending of the energy band of TiO2 by approximately 0.2 eV, and the Fermi level also shifted to the valence band, without any effect on the band gap. The I–V characteristics varied in vacuum and air, with ideal factors (η) of 4.1 and 8.72, respectively. The study is expected to broaden the application scope of doped photodiodes.