Effect of Organic Dye Concentration on the Nanostructured TiO₂‐Based Diodes

In this study, A/TiO 2 /FTO, A/(CV (Crystal Violet) dye) X ‐TiO 2 /FTO Schottky diode devices (A = Ag/Au), (X = 1.0, 1.5, 2.0, 2.5, 3.0 mg) with TiO 2 nanostructures are fabricated. The TiO 2 nanostructures are synthesized using the hydrothermal method on the FTO substrate. The samples' dark current–voltage ( I–V ) characteristics are studied with a B1500A semiconductor parameter analyzer. The devices exhibited good rectifying behavior at room temperature. Ideality factor ( η ), barrier height ( φ b ), and series resistance ( R S ) are calculated from I–V measurements at room temperature by fitting with thermionic emission theory, Norde method, and Cheung method. The obtained results reveal that various CV dye concentration affects the important junction parameters of the fabricated Schottky diodes, such as ideality factor ( η ), barrier height ( φ b ), and series resistance ( R S ). However, a systematic change is not observed as the number of CV aggregates between the TiO 2 and the electrode might be different for each device. However, a low series resistance is obtained with these nanostructures in the order of a few Ω–kΩ. It is found that barrier height did not change much on varying CV dye concentrations. Hence, these dye‐sensitized TiO 2 nanostructures can be used to make diodes.