Characterization of prepared In2O3 thin films: The FT-IR, FT-Raman, UV-Visible investigation and optical analysis.

In this original work, the Indium oxide (In2O3) thin film is deposited cleanly on microscope glass substrate at different temperatures by spray pyrolysis technique. The physical properties of the films are characterized by XRD, SEM, AFM and AFM measurements. The spectroscopic investigation has been carried out on the results of FT-IR, FT-Raman and UV-Visible. XRD analysis exposed that the structural transformation of films from stoichiometric to non-stoichiometric orientation of the plane vice versa and also found that, the film is polycrystalline in nature having cubic crystal structure with a preferred grain orientation along (222) plane. SEM and AFM studies revealed that, the film with 0.1M at 500°C has spherical grains with uniform dimension. The complete vibrational analysis has been carried out and the optimized parameters are calculated using HF and DFT (CAM-B3LYP, B3LYP and B3PW91) methods with 3-21G(d,p) basis set. Furthermore, NMR chemical shifts are calculated by using the gauge independent atomic orbital (GIAO) technique. The molecular electronic properties; absorption wavelengths, excitation energy, dipole moment and frontier molecular orbital energies, molecular electrostatic potential energy (MEP) analysis and Polarizability first order hyperpolarizability calculations are performed by time dependent DFT (TD-DFT) approach. The energy excitation on electronic structure is investigated and the assignment of the absorption bands in the electronic spectra of steady compound is discussed. The calculated HOMO and LUMO energies showed the enhancement of energy gap by the addition of substitutions with the base molecule. The thermodynamic properties (heat capacity, entropy, and enthalpy) at different temperatures are calculated and interpreted in gas phase.

Structural, optical and electrical properties of Zr-doped In2O3 thin films.

Undoped and zirconium doped indium oxide (ZrIO) thin films were deposited on glass substrate at a substrate temperature of 450°C by spray pyrolysis method. The effect of zirconium (Zr) dopant concentration (0-11 at.%) on the structural, morphological, optical and electrical properties of n-type ZrIO films were studied. X-ray diffraction (XRD) results confirmed the polycrystalline nature of the ZrIO thin film with cubic structure. The grain size was decreased from 25 to 15.75 nm with Zr doping. The scanning electron microscopy (SEM) showed that the surface morphology of the films were changed with Zr doping. The surface roughness of the films was investigated by atomic force microscopy (AFM) and was found to be increased with the increasing of Zr doping percentage. A blue shift of the optical band gap was observed. The optical band was gap decreased from 3.50 to 3.0eV with increase in Zr concentrations. Room temperature photoluminescence (PL) measurement of the deposited films indicated the incorporation of Zr in In2O3 lattice. The film had low resistivity of 6.4 × 10(-4)Ωcm and higher carrier concentration of 2.5 × 10(20) was obtained at a doping ratio of 7 at.%.

Spectroscopic analysis, structural, microstructural, optical and electrical properties of Zn-doped In2O3 thin films.

In this work, highly transparent conducting un-doped and Zn-doped In2O3 thin films were prepared onto glass substrate using spray pyrolysis method. Structural, morphological, optical and electrical properties were characterized by using XRD, FT-IR, FT-Raman, SEM, AFM, UV-visible, PL and Hall Effect measurement techniques. X-ray diffraction analysis showed that the deposited films were polycrystalline with cubic structure having (222) as preferred orientation. SEM and AFM analyses showed smooth surfaces but the surface roughness of the films increased due to Zn doping. The average optical transmittance of the films was above 94% in the visible range. The optical band gap decreased from 3.62 to 3.28 eV with increasing Zn concentration. The photoluminescence spectra displayed violet-blue emission peaks at around 418-440 nm for all films. The electrical parameters like the resistivity, mobility and carrier concentration were found as 6.4×10(-4) Ω cm, 168 cm(2)/Vs and 9.4×10(20) cm(-3), respectively for In2O3:Zn film deposited at 9 at.%. The present results showed that the obtained thin films could be used as an optoelectronic material.