Hall Effect Measurement and Current–Voltage Features of Roselle Plant (Hibiscus Sabigriffa) Dye-Doped Nano Crystalline-TiO2 and the Effect of Sensitization on Dye Sensitized Solar Cell

Abstract

Hall Effect measurement of thin films is one of the methods used to ascertain the electrical resistivity of thin film, sheet resistance of thin film, conductivity of the thin film, Hall mobility of the thin film, charge carrier density and type of charge carriers present in a particular cell or film. The thin films were developed using the screen printing technique to deposit TiO₂ on the substrate and the Chemical vapour deposition method to develop Fluorine doped Oxide layer on the substrates. The semiconductor (TiO₂) blocking band was developed by adding 0.1 mole of titanium isopropoxide and 0.4 mole of acetyle acetone to the substrate using spin coating method. The Hall effect analysis carried out shows the following results: mobility charge = 1.303 cm²/Vs, bulk concentration= -5.274 /cm³, sheet resistance =4.641  Ω ̸ □, resistivity = 9,081E-3Ω cm, A-C cross hall coefficient = -2.092E-2 Cm³ ̸ C, magneto –resistance = 6.729E-2Ω, sheet concentration = -1.055/cm², conductivity = 1.101E+2 /ΩCm, average hall coefficient = -1.184E-2 Cm³/C, B-D cross hall coefficient = -2.757E-3 Cm³/C and ratio of vertical / horizontal = 8.887E-1. We deduced that the charge carrier discovered in the developed FTO down to block band dyed semiconductor (TiO₂) films is a p-junction semiconductor type of charge carrier since the mobility charge value is positive with value of 1.303E+0Cm²/Vs. When the mobility charge value is negative, it becomes n-junction type. Other characterization analyses were carried out.