Novel diode-shaped ZnO nanocrystals

Structure and Formation Mechanism of Sn-Doped ZnO Nanoneedles

“…Inourcase,thegrowthofZnOnanoneedleswasdonewithout catalyst.Therefore,theformationmechanismofthenanoneedles wasthoughttobecontrolledbythetraditionalvapor-solid(VS) mechanism.Thismechanismconsistsoftwostages:onenucleationandanothergrowth.Atthetemperatureof650 益 (higher thanthemeltingpointsofSnat231.9 益 andZnat419.5 益),the Sn:Znthinfilmsaremeltedandaggregatedtoformthemicro鄄 sizedZn鄄Snalloydropletsonthefilmsurface.Meantime,trace amountofO 2 fromArmaysolveintotheoutersurfaceofthe previouslyformedZn鄄SndropletstoformSn鄄Zn鄄Oeutectic droplets.ZnismoreactivethanSninchemicalproperty [24] ,as thesupersaturatedstateofaggregateddropletsappeared;ZnO begantodiffusethroughtheliquidphase,whereZnOcrystalline nucleiwereformed.Withtheoxygengasescontinuouslysolving intotheliquidZn鄄Sndroplets,theseZnOnucleiindividuallyunderwentaveryrapidrootgrowthprocess [25] ,consumingtheZn fromthehighmobilityZn鄄Snliquiddropletstoformnanobelts inrandomlydirections.Atthesametime,Snwasdopedintothe ZnOparticlesthroughtheprocessofSnsubstituteZnatomin ZnO.DuetothereductionofZnfromthemicropaticles,thediameterofthemwillgraduallydecreasefromtheroottothetop tilltheZnsourceisalmostusedup,whichresultsinthecreation ofZnOnanoneedles.ThesizeandshapeofSn鄄Zn鄄Odropletsare presumablydominantfactorsforthemorphologyandcrystallini-tyofSn鄄dopedZnOnanoneedles.…”

ZnO:Ga nanowires with low turn-on field for field-emission lighting

“…Consequently, the nanowire was elongated and its aspect ratio was increased. Clearly, doping of Ga 3+ suppresses three-dimensional development of ZnO but facilitates the growth of ZnO in longitudinal directions; this shows the configuration-limiting ability of Ga[37]. The Ga 3+ ion concentrations in the ZnO:Ga nanowires, as measured by EDS, were 0.24 and 0.36 at%, respectively, when doped with 0.5 and 1 mol% Ga 3+ .…”

Preparation of new morphological ZnO and Ce-doped ZnO

“…It presents interesting electrical, optical, acoustical and chemical properties, which find wide applications in optical and electrical devices [1]. Recently, ZnO has been extensively studied because of its potential applications in various fields, such as: gas sensors [2], solar cells [3], photodetectors [4], light emitting diodes (LEDs) [5] and laser systems [6] ...etc. Various morphologies of ZnO such as nanowires [7], nanorods [8], nanotubes [9], nanobelts [10], nanorings [11], nanoneedles [12], nanodisks [13], nanocones [14] ...etc.…”