Fabrication and characterization of undoped and cobalt doped NiO-based diodes

In this study, undopedandcobalt-dopednickeloxidethinfilmsweredeposited on glasssubstratesand n-typesiliconsubstratesby sol gel spin coatingmethod.Inthefirst step, theelectricalconductivity of thinfilms, whichwascoated on glasssubstrates, wasinvestigated.Then, heterojunctionstructureswereproducedbythinfilmscoated on n-Si substrates. Theforwardandreversecurrent-voltage (I-V) characteristics of heseheterojunctionstructureswereinvestigatedbyusingThermionicEmission (TE) theory.Itwasobserved that allfabricatedstructuresexhibitedrectificationbehavior. Thebasicelectricalparameters of thediodesuch as idealityfactor (n), barrierheight (ΦB), rectificationratio (RR) andseriesresistancewerecalculatedandcompared. As a result of themeasurements, theeffect of cobalt doping on thefabricatedheterojunctionswasinvestigated. Inaddition, capacitance-voltage (C-V) andconductivity-voltage (G/w-V), seriesresistance-voltage (Rs-V) andinterfacestates (Dit) graphswereplottedandanalyzed in thefrequencyrange of 10 kHz – 1 MHz. Electricalparametres of diodessuch as Nd (cm-3), Vbi (eV), Nc (cm-3), Ef (eV), Փb (CV)Ev, Wd (nm), ∆Փb (eV) andEmax (V/cm) werecalculatedbyusingthecapacitancevalues at 1 MHz. As a result of thecalculations, it wasobserved that allelectricalparameterswerestronglydependent on theamount of dopant. Inaddition, this studyshows that electricalparameters of diodes can be adjustedwithcobalt doping.