Recent reports indicate that thin films of oxides of zinc: ZnO, Zn(O,S), or Zn-Mg-O, could be a better buffer component than CdS to provide an adequate band alignment with orthorhombic tin sulphide in thin lm solar cells. Thin films of ZnO were grown by rf-magnetron sputtering on different substrates at room temperature. Thin films of ZnO obtained by different deposition methods show hexagonal crystal structure, usually with a preferential orientation of (002) crystallographic planes parallel to the substrate surface. However, in the present study XRD patterns indicate that thicker ZnO films on glass substrates have preferential growth of (103) planes, while that on chemically deposited CdS or ZnS films preferential orientation of (002) planes persists. Bandgap of ZnO films increases from 3.2 eV to 3.4 eV when the chamber pressure used for deposition varies from 2.3 mTorr to 6 mTorr. ZnO films were incorporated in a solar cell structure stainless steel/SnS(cubic)/SnS(orthorhombic)/SnS(cubic)/CdS/ZnO/ZnO:Al. It showed open-circuit voltage of 0.318 V, short-circuit current density of 3.6 mA/cm<sup>2</sup> and conversion efficiency of 0.82%.
Transparent conducting indiuim galium zinc oxide (IGZO) films were successfully grown on glass substrates at room temperature by rf magnetron sputtering. Structural, optical, morphological and electrical properties of IGZO films deposited at different rf power were investigated. Composition of the film was analysed by EDAX measurement which shows that percentage of Zn increased with the rf power. Surface morphology of the IGZO film measured from AFM analysis showed that the roughness of the film was increased with increase in RF power. The average transmission in the visible range was greater than 80% and the transmission in the higher wavelength region decreased with increase in RF power. The carrier concentration in IGZO films could be controlled by controlling rf power due to the increase of Zn/(Ga+In+Zn) ratio. Nonlinear properties of IGZO thin films were measured using z-scan technique. Increase in free electron concentration of IGZO thin films lead to a decrease of the corresponding nonlinear optical absorption response.
n-Type transparent conducting indiuim galium zinc oxide (IGZO) films were successfully grown on glass sub- strates at room temperature by rf magnetron sputtering . Structural, optical, morphological and electrical properties of IGZO films deposited at different rf power were investigated.Composition of the film was confirmed by EDAX measurement which shows that percentage of Zn increased with the rf power. Structural studies by X-ray diffraction showed that as deposited IGZO films were amorphous. The roughness of the film was increased with increase in rf power and smooth film of average roughness 0.75nm was obtained at 40W rf power. The average transmission in the visible range was greater than 80% and the transmission in the higher wavelength re- gion decreased with increase in RF power. Refractive index of IGZO film calculated by Swanepoel technique was 1.92. The carrier concentration in IGZO films can be controlled by controlling rf which can vary Zn/(Ga+In+Zn) ratio. The bottom gate structured transparent TFTs fabricated using n-type IGZO active layers operated in enhancement mode with field effect mobility 2.5 cm<sup>2</sup>/Vs and threshold voltage 20V.
In the present study, we report the growth of silver nanoparticles in SiO2 matrix by co- sputtering
technique. The effect of deposition conditions on the formation of Ag nanoparticles were systematically
studied using scanning electron microscopy (SEM), UV-Vis absorption studies. The optical absorptive
nonlinearity of the nanoparticles was studied by using open aperture Z- scan techniques. The surface
plasmon peak in the absorption spectra indicates the presence of Ag nanoparticles in the matrix. The open
aperture Z-scan studies shows the Ag- SiO2 nanocomposites can be used as a good optical limiter.