Electrical transport properties and impedance analysis of Pt/TiO2 Nanorods/FTO heterojunction device

Presented study focuses on the hydrothermal growth of Titanium Oxide (TiO2) vertical nanorods on a FTO substrate, leading to the realization of a Schottky junction through the evaporation of platinum onto the TiO2 nanorods. I-V (current-voltage), EIS (electrochemical impedance spectroscopy) measurements were carried out to characterize the fabricated heterojunction devices. The barrier height of 0.6 eV and ideality factor value were obtained of 16 indicate the presence of an interfacial layer in the heterojunction devices. Effective charge carrier mobility of ∼ 0.01842 cm2/Vs is determined through the application of Mott-Gurney's law. Conductivity and density of deep trap states (ntrap) were found to be ∼ 1.5595 × 10−8 (Ω cm)−1 and ∼ 1.4 × 1022 m−3 respectively. Additionally, the scanning Kelvin probe (SKP) technique is employed to investigate the contact potential difference (CPD) and work function of TiO2, while the mechanical behaviour of TiO2 nanorod arrays is studied using nanoindentation.