Optical, Dielectric and Optoelectronic Properties of Spray Deposited Cu-doped Fe2O3 Thin Films

Copper-doped hematite thin films were prepared by spray pyrolysis technique using a mixture of ethanol and distilled water precursors. Visual observations showed that aqua precursor produced less integrity compared with thin, uniform transparent yellowish-brown adhered well to the substrate. Composition thickness measurements determined RBS revealed thinner 94.45 51.77 nm while 1,370 1,120 for undoped Cu-doped Fe2O3 respectively. This is an indication solutions nano-thick high integrity. The composition only deposited solution gave close stoichiometric others non-stoichiometric Fe(OH)3 . Optical characterization carried out UV-visible spectrophotometer in transmittance mode indicated film was directly proportional number passes which inversely transmittance. Three bandgap determination methods namely; Tauc, Absorption Fitting Spectrum (AFS) Davis-Mott employed result Tauc AFS direct indirect energies (Eg) 3.44 1.98 3.43 2.32 eV Urbach tail energy 1,100 meV broad onset absorption. steepness parameter (?) found be 7.83 electron-phonon (Eph ) coupling 0.85 eV. It also observed refractive index (n) about 15 times greater than extinction coefficient (k). In study dispersion parameters single oscillator Sellmier models, values (Eosc ), (Ed), zero frequency dielectric constant, index, average strength (So), determined. All estimated are same order magnitude other semiconducting materials. could as material optoelectronic devices.