CuZnS and CuZnS/Au NPs layer with different Cu/Zn content thin films have been deposited on heated glass substrate by spray pyrolysis technique at 330 °C and annealed at 450 °C for 1 hour. X-ray diffraction (XRD) results reveals that the structures of all prepared thin films are polycrystalline in nature, with preferential growth orientation along (111) plane corresponding to the cubic ZnS (sphalerite). Two low crystallinity of crystallographic phases corresponding to hexagonal CuS and monoclinic Cu2S were appeared with Cu/Zn different content. Strong diffraction peak of Au NPs appeared in CuZnS/Au NPs layer structure corresponding to the cubic Au gold phase oriented along (111) plane. Structure parameters such as crystallite size and number of crystalline, dislocation density and micro strain have been determined. Scanning Electron Microscopy (SEM) and Atomic force microscope (AFM) images of CZS, and CZS/Au NPs thin films shows smooth, uniform morphology and plated regularly with no detectable micro-cracks. The roughness and r.m.s. roughness was increased with increase of Cu/Zn content from 1.95 nm to 4.36 nm respectively, while it decreased with the exists of Au NPs layer from 20.9nm to 3.99 nm. The energy dispersion x-ray spectroscopy spectra demonstrate the stoichiometry of the deposited films. The optical properties results exhibits red shifted in the fundamental absorption edge towards low energies of CZS (Cu/Zn content) and CZS/Au Nps layer thin films. The optical energy gap has been decreased from (2.56 to 2.34 eV, and 2.62 to 2.32 eV) with respect to Cu/Zn content and Au Nps layer, respectively.

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Au nanoparticles doped CuZnS (CZS) thin films were deposited by spray pyrolysis method (SPD) onto glass and silicon substrates at temperature of 330 ºC and annealed at 450ºC. Cu:Zn:S content was 1:1:2 and Au NPs dopant ratio was 4%, 6% and 8%. The structural, surface morphology, optical and photodetector properties were investigated with respect to the dopant concentration. X–Ray diffraction patterns indicate that the films have low crystallinity and polycrystalline structure nature with ZnS sphalerite cubic phase. The intensity of diffraction peaks and the crystallite size increased with the increase of Au Np's dopant ratio.  The SEM images show a homogeneous and smooth uniform surface. Also AFM images reveals that the roughness increased from1.95 nm for CZS (1:1:2) to 2.64 nm for CZS:Au (4%), 4.86 nm for CZS:Au (6%) and 3.82 nm for CZS:Au (8%)  thin films, these increases could be probably due to the increasing concentration of atomic gold in the CZS thin films, The average grain diameter was evaluated from the plane view images for 68.99 CZS 1:1:2 and CZS:Au NPs was (93.59–102.07 nm). Au Np's dopant ratio, the lower band gap corresponds to CuxS phase and double band gap confirms the alloy nature of material. The decreased in energy band gap after increasing of Au Np's dopant ratio can be attributed to the red shift of the absorption edge and to the improvement in the crystallinity, increase of Au Np's ratio leads to decrease band gap from 2.5 eV to 2.39 eV. Photodetectors CuZnS: Au Np's/Si were synthesized and I–V characteristics have been investigated, the results showed that the photocurrent increased from 0.0 to (8.65×10-7 A, 5.62×10-6 A and 5.03 ×10-6 A)   at the bias voltage range of 0– 2V under illumination, and from 0.0 to (3.49 ×10-7 A, 1.9 ×10-6 A and 3.14 ×10-6A)  in the dark for CZS:Au NPs (4%, 6% and 8%) ratio, respectively. Under applied voltage of 2V, the response time was (0.8, 0.5 and 1.5 sec) respectively; whereas the recovery time was (0.6, 0.9 and 1.35 sec) and the sensitivity increased from 42.86% to 122.73%.

CO2 Gas is considered one of the unfavorable gases and it causes great air pollution. It’s possible to decrease this pollution by injecting  gas in the oil reservoirs to provide a good miscibility and to increase the oil recovery factor. MMP was estimated by Peng Robinson equation of state (PR-EOS). South Rumila-63 (SULIAY) is involved for which the miscible displacement by  is achievable based on the standard criteria for success EOR processes. A PVT report was available for the reservoir under study. It contains deferential liberation (DL) and constant composition expansion (CCE) tests.  PVTi software is one of the (Eclipse V.2010) software’s packages, it has been used to achieve the goal.  Many trials have been done to match the data of DL test by tuning some of the PR-EOS parameters through the regression analysis process, but no acceptable match was obtained especially for saturation pressure. However; splitting the mole fraction of (C6+) to many pseudo components was carried out, and then a regression analysis process was made again to improve the matching by tuning some of the PR-EOS parameters. A good estimate of saturation pressure and a good match of PVT properties was noted. Ternary diagram has been constructed to represent the phase behavior of -Oil and to calculate MMP for the South Rumila-63 (SULIAY) oil well.