简介:Windowcoatingusedforthebuildinginrecentyearsisdescribed.Importantdesignprinciples,practicalcoatingmaterials,andattainableopticalpropertiesforresearch-typecoatingsareintroduced.Discussioniscarriedoutonthespectrallyselectivecoatings,theelectrochromiccoatings,andthethermochromiccoatings.
简介:Thetransmissionpropertiesofdouble-ringsplitringresonator(SRR)arraysandclosedringresonatorarraysaremeasuredusingterahertz(THz)time-domainspectroscopy.Thistechniqueallowsforthesimultaneousmeasurementoftheamplitudeandphaseofthetransmissioncoefficientasafunctionoffrequency.Theabilitytodirectlymeasurethephasespectrumisexpectedtobeimportantincharacterizingpotentialnegativeindexmedia.Intheemployedexperimentalgeometry,THzpulsesarenormallyincidentonthearrays.Thus,themagneticfieldliesintheplaneofthearraysandcannotcontributetothemagneticresonanceoftheSRR.However,itisfoundthattheelectricfield,whenappropriatelypolarized,cancoupletothemagneticresonance.ShiftsintheresonancepropertieswithchangesintheSRRdimensionsandthesubstratemediumaremeasured,theresultsofwhichareconsistentwiththeory.
简介:Tosensitizepolyanilinewithdyesbyelectrochemicalpolymerization,HClO4isemployedasthedopantandoxidant,andthepolyanilinewithdiffernetsensitivepropertiesissynthesized.Theeffectofsensitizedemeraldinesaltontheabsorptionspectrumisdiscussedindetails.Themaximumconductivityofsensitizedfilmsreaches1.22S/cm,andinvestigationondyesensitizingofthepolymerrevealsthatC.I.DirectBlue71,C.I.DirectBlue84,C.I.DirectBlack19andCuPc-(COOH)4mayenhancethephotoconductivityofpolyanilinegreatly.
简介:Theliquidcrystalcompositematerialsconsistofmicrodroplersofliquidcrystalswhicharespontaneouslyformedinamatrixofapolymeratthetimeofitspolymerization.Thedirectorconfigurationinliquidcrystaldroplets.themodeloforientationofdroplets,andthecontrastratiosofacellareinvestigated.Dropletsize,spacinganddistributionarereadilycontrolledinthesematerialstoallowoptimizationofdisplaysbaseduponelectricallycontrolledlightscatteringfromtheliquidcrystaldroplets.Preliminaryexperimentalandtheoreticalstudiesofthelightscatteringandelectro-opticresponseofnewmaterialshowthatthesematerialscanoffernewfeaturessuitableforlargeareadisplaysandlightvalves.
简介:Waveguidingpropertiesofsilicananowiresinvariousenvironmentsarestudiedbysolvingtheeigenvalueequationsofacircularcross-sectionwaveguidenumericallyincylindricalcoordinates.Thesingle-modecondition,propagationconstants,poyntingvectorandpowerdistributioninsideandoutsidesilicananowirearecalculated.Theresultsshowthatsilicananowiresinwater,comparedwithsilicananowiresinair,havehigherfractionoftheevanescentfields.Duetothesensitivitytosurroundingenvironment,silicananowiresareverysuitableforsensingelements,whichcanbeusedtoimplementasingle-modefiberopticevanescentwavesensingelementofhighlysensitiveandaccuratemeasurement.
简介:Dopedmicro-crystallinesiliconfilmsaredepositedattemperaturesaslowas400℃bythecatalyticchemicalvapordepositionmethodusingasilaneandhydrogengasmixture.ElectricalpropertiessuchasthecarrierconcentrationandtheHallmobilityareinvestigatedforvariousmeasuringtemperatures.Itisfoundthatthegrainsofmicro-crystallinesiliconarepreferentiallyorientedalongthe(220)direction,andthattheHallmobilityislargerthan8cm^2·V^-1·s^-1,thecarrierconcentrationisabout1×10^17cm^-1-1×10^19cm^-3atroomtemperature.
简介:Hybridorganic-inorganicperovskites(e.g.CH3NH3PbI3)haveattractedtremendousattentionduetotheirpromiseforachievingnext-generationcosteffectiveandhighperformanceoptoelectronicdevices.Thesehybridorganic-inorganicperovskitespossessexcellentopticalandelectronicproperties,includingstronglightabsorption,highcarrierabilities,optimizedchargediffusionlengths,andreducedchargerecombinationetc.,leadingtotheirwidespreadapplicationsinadvancedsolarenergytechnologies(e.g.highefficiencyperovskitesolarcells).However,thereisstillalackofinvestigationsregardingfundamentalpropertiessuchasferroelectricityintheseperovskites.Asconventionalferroelectricceramicsarepreparedathightemperatureandhavenomechanicallyflexibility,low-temperatureproceedandflexibleperovskiteferroelectricshavebecomepromisingcandidatesandshouldbeexploitedforfutureflexibleferroelectricapplications.Here,ferroelectricpropertiesinhybridorganic-inorganicperovskitesandseveralstate-of-theartperovskiteferroelectricsarereviewed.Novelferroelectricapplicationsofhybridorganic-inorganicperovskitesarediscussedaswell,providingguidelineforrealizingfuturehighperformanceandflexibleferroelectricdevices.
简介:In_2O_3∶SnO_2(ITO)thinfilmswerefabricatedonthesubstrateofflexiblepolyethyleneterephthalate(PET)byDCmagnetronsputteringfromaceramictargetofIn_2O_3/SnO_2(90∶10).PropertiesofthethinfilmswerecharacterizedbyX-raydiffraction(XRD),four-pointprobe,Hall-effectmeasurement,UV-Visspectrophotometer,andscanningelectronmicroscopy(SEM).Theeffectsofsputteringpressure,oxygenpartialpressureanddepositiontemperatureonpropertiesofmicrostructureandoptoelectronicspropertiesofPET/ITOthinfilmswereinvestigatedindetail.High-qualityITOthinfilmsonPETsubstrateswiththeresistivityaslowas8.5×10-4Ω·cmandtheopticaltransmittanceover80%inthevisiblespectrumrangewereobtained.
简介:Cu-andCo-substitutedNiZnferritethinfilms,Ni0.4-xZn0.6CuxFe2O4andNi0.5Zn0.5CoxFe2-xO4(0≤x≤0.2),aresynthesizedbysol-gelprocess.ThecrystallographicandmagneticpropertiesofCu-andCo-substitutedNiZnferritethinfilmshavebeeninvestigated.ThelatticeparameterdecreaseswithCusubstitutionandincreaseswithCosubstitution.ThesaturationmagnetizationdecreasesandthecoercivityincreaseswiththeincreaseofCusubstitution.Moreover,thesaturationmagnetizationgraduallyincreaseswiththeincreaseofCosubstitutionwhenx≤0.10,butdecreaseswhenx>0.10.Meanwhile,thecoercivityinitiallydecreaseswiththeincreaseofCosubstitutionwhenx≤0.10,butincreaseswhenx>0.10.
简介:Nitrogen-dopedamorphouscarbonthinfilmsaredepositedontheceramicsubstratescoatedwithTifilmbyusingdirectcurrentmagnetronsputteringtechniqueatN2andArgasmixtureatmosphereduringdeposition.Thefieldemissionpropertiesofthedepositedfilmshavebeeninvestigated.Thethresholdfieldaslowas5.93V/μmisobtainedandthemaximumcurrentdensityincreasesfrom4μA/cm2to20.67μA/cm2at10.67V/μmcomparingwithundopedamorphousfilm.Theresultsshowthatnitrogendopingplaysanimportantroleinfieldemissionofamorphouscarbonthinfilms.
简介:ThepreparationofPT/PEK-cfilmsisreportedaswellastheirdielectricandopticalproperties.Thec-axisorientationratioofthefilmsis68%.Dielectricconstantandlossfactorat10kHzisabout4.023F/mand0.003,respectively.Therefractiveindicesofthefilms,neandno,are1.6573and1.6278at0.63μmwavelength,respectively.Theopticalband-gapofthefilmwithathicknessof2.33μmisfoundtobe3.06eV
简介:Cr-dopedZnOthinfilmsarepreparedonglasssubstratesbythemagnetronsputteringtechnique.AnX-raydiffraction(XRD)isusedtoanalyzethestructuralpropertiesofthethinfilms.Itindicatesthatallthethinfilmshaveapreferentialc-axisorientation.Thepeakpositionofthe(002)planeshiftstothehigher2θvalue,andthepeakintensitydecreaseswiththeincreaseofCrdoping.Theresultsofthescanningelectronmicroscopy(SEM)showthatthesurfacemorphologybecomesloosewiththeincreaseofCrdoping.Besides,itisfoundfromthephotoluminescence(PL)measurementatroomtemperaturethattheultravioletemissionpeakandgreenemissionbandarelocatedat375nmand520nm,respectively,andbothintensitiesofthemdecreasewiththeincreaseoftheCrdopingconcentration,whilethebandgapoftheultravioletemissionshiftstothelowerwavelength.TheexperimentalresultsconfirmthattheoptimalCrdopingconcentrationis2at.%.
简介:Thedielectricpropertiesofceramicswithcompositionof(Sr1-xBix)TiO3+x/2(wherex=0.05~0.70)weremeasuredatfrequencyof1MHz.Theexperimentalresultsindicatethatthedielectricpropertiesof(Sr1-xBix)TiO3+x/2systemaregreatlyvariedwithanincreaseofthestoichiometricamountsofBi2O3.Therelativepermittivityofthesolidsolutionsishigh,andthedissipationfactorislow.Thepositronannihilationtechnique(PAT)wasadoptedtostudythedefectstructure.AnexplanationofthedielectricpropertiesofBi-dopedSrTiO3ceramicshasbeensuggestedintermsofelectron-compensationandvacancyordefect-compensationmechanismsandspace-chargepolarizationmechanism.
简介:TheinvestigationonopticalpropertiesofSi1-xGex/Sistrainedlayerstructureshasbeencarriedoutactivelyinrecentyears.Thephotoluminescencehasbe-comeabriskersubjectinthestudiesofitsvariousopticalproperties.Aresearchdevelop-menttophotoluminescencepropertiesofsomenewSi1-xGex/Sistrainedlayerstruc-turesisintroduced.