Heterostructure Device Based on Graphene Oxide/TiO ₂ /n-Si for Optoelectronic Applications

Abstract

We produced a graphene oxide with good conductivity by a novel method that saves cost and time as illustrated in the structure Au/GO/TiO 2 /Si/Al. The GO was synthesized by burning polyvinyl alcohol at 300 °C on the TiO 2 /n-Si surface producing a conductive graphene oxide that is considered a new advantage of this technique. The Au/GO/TiO 2 /n-Si/Al structure is manufactured using the spin coating process. The XRD and SEM identified the samples’ structure and surface topography. In a frequency range from 10 kHz to 20 MHz, the electrical and dielectric parameters of the synthetic Schottky diodes were obtained from capacitance/conductance-voltage. The diagram of real and imaginary parts of the impedance (Z′, Z″), col-col, and their variation with temperatures, voltage, and frequency were also discussed. A comparison of electrical parameters such as ideality factor (n), series resistance (R s ), barrier height (Φ b ) based on traditional, Cheung, and Norde methods was investigated. The oxide layer thickness values (d ox ), the density distribution (N ss ), the maximum admittance (Y m ), the maximum electric field (E m ), the depletion layer width (W d ), and ΔΦ b (eV) were investigated using the C 2 − V relationship. As the frequency increases, the Φ b(C−V) increases, while the concentration of donor atoms (N D ) decreases. The surface states (N ss ) voltage-dependent profile was calculated and evaluated.