Page - 158 - in Photovoltaic Materials and Electronic Devices

Thisprocessinghasaneffectontheoxygenvacanciesdensitiesevenfor the0sccm O2 films. Surfaceroughness increasedas theconcentrationofoxygenincreasedas expected. The etching reactions are simple redox reaction, hence the rates should increasewith increases inO2 concentrationespecially fornon-stoichiometricfilms with distorted ITO matrix. The etch rate, preferred crystal lattice growth plane, d-spacingandlatticedistortionwerealsoobservedtobehighlydependentonthe natureofgrowthenvironment forRFsputterdepositedITOfilms. Acknowledgments: Acknowledgments: This work was supported by the National Science Foundation under grant award number CBET-1235750 and the Fulbright S&T award. JeyanthinathMayandithankstheUniversityGrantsCommission(UGC)forprovidingsupport throughRamanfellowship2014–2015tovisitMichiganTechnologicalUniversity,Houghton, MI49931,USA. AuthorContributions: AuthorContributions: Jephias Gwamuri, Jeyanthinath Mayandi and JoshuaM.Pearceconceivedanddesignedtheexperiments; JephiasGwamuri, Jeyanthinath Mayandi, Murugesan Marikkannan and Patrick K. Bowen performed the experiments; all authors analyzed the data; Jeyanthinath Mayandi and Joshua M. Pearce contributed materials andtools; andallauthorswrote thepaper. Conflictsof Interest: Conflictsof Interest: Theauthorsdeclarenoconflictof interest. Abbreviations 4-PP FourPointProbe AFM AtomicForceMicroscopy a-Si:H HydrogenatedAmorphousSilicon AZO AluminumdopedZincOxide c-Si CrystallineSilicon DC DirectCurrent FTO Fluorinedoped-Tinoxide ITO IndiumTinOxide PV Photovoltaic RF RadioFrequency SCCM StandardCubicCentimetersperMinute (flowunit) SLG SodalineGlass SnO2 TinOxide TCOs TransparentConductingOxides VASE VariableAngleSpectroscopicEllipsometry XRD X-rayDiffraction ZnO ZincOxide 158