简介:Athree-dimensionalmodelofGaAs/A1GaAsquantumdoubleringsinthelateralstaticelectricfieldisinvestigatedtheoretically.Theeigenvalueproblemwiththeeffective-massapproximationissolvedbymeansofthefinite-elementmethod.Theenergylevelsandwavefunctionsofquantum-confinedelectronsandheavyholesareobtainedandshowanagreementwithourprevioustheoreticalandexperimentalstudies.ItisshownintheapproximationofneglectingtheCoulombattractionbetweentheelectronandheavyholethatarelativelylargeStarkshiftofexcitonemissionof4meVisattainablewithanappliedelectricfieldof0.7kV/cm.
简介:The810-nmInGaAlAs/AlGaAsdoublequantumwell(QW)semiconductorlaserswithasymmetricwaveg-uidestructures,grownbymolecularbeamepitaxy,showhighquantumefficiencyandhigh-powerconver-sionefficiencyatcontinuous-wave(CW)poweroutput.Thethresholdcurrentdensityandslopeefficiencyofthedeviceare180A/cm~2and1.3W/A,respectively.Theinternallossandtheinternalquantumefficiencyare1.7cm~(-1)and93%,respectively.The70%maximumpowerconversionefficiencyisachievedwithnarrowfar-fieldpatterns.
简介:Atheoreticalinvestigationiscarriedoutintothecrossphasemodulation(XPM)inanasymmetricdoubleAlGaAs/GaAsquantumwellsstructurewithacommoncontinuum.Itisfoundthat,combiningresonanttunneling-inducedtransparencyandconstructiveinterferenceinthethird-orderKerreffect,agiantXPMcanbeachievedwithvanishinglinearandnonlinearabsorptions,accompaniedbythevelocitiesoftheprobeandsignalfieldsbeingmatched.Furthermore,thisgiantXPMcouldinduceaπ-phaseshiftatasingle-photonlevelwhichisfavorablefortheapplicationsintwo-qubitquantumlogicgates.
简介:Adouble-slitghostinterferenceexperimentperformedonanentangledresourceusingtype-IInon-collineardegeneratespontaneousparametricdown-conversion(SPDC)isdemonstrated.Theinfluenceofthedistancebetweenthedouble-slitandthebucketdetectorprecededbyapinholeisstudied.Theexperimentalresultsshowthattheinterferencefringesbecomeincreasinglydistinctwithhighervisibilitywhenthepinhole-double-slitdistanceincreases.Afirst-orderclassicaltheorybasedontheKlyshko’stwo-photonadvanced-wavepicture,andasecond-orderquantum-imagetheoryareprovidedforexplanations.Thefittingresultsindicatethatthedivergenceoftheconvertedfluorescencesignificantlyaffectstheghostfringes.
简介:Wefabricatewhitephosphorescentorganiclight-emittingdiodes(PHOLEDs)withthreedopantsanddoubleemissivelayer(EML)toachievecolorstability.ThewhitePHOLEDsuseFIrpicdopantforblueEML(BEML),andIr(ppy)3:Ir(piq)3dopantsforgreen:redEML(GR-EML)withN,N′-dicarbazolyl-3,5-benzene(mCP)ashostmaterial.ThicknessesofB-EMLandGR-EMLareadjustedtoformanarrowrecombinationzoneattwoEML’sinterfaceandchargetrappinghappensinEMLaccordingtowidehighestoccupiedmolecularorbitaland/orlowestunoccupiedmolecularorbitalenergybandgapofmCPandsmallerenergybandgapofdopants.ThetotalthicknessofbothEMLsisfixedat30nminthedevicestructureofITO(150nm)/MoO3(2nm)/N,N′-diphenyl-N,N′-bis(l-naphthyl-phenyl)-(l,l′-biphenyl)-4,4′-diamine(70nm)/mCP:Firpic-8.0%(12nm)/mCP:Ir(ppy)3-3.0%:Ir(piq)3-1.5%(18nm)/2′,2′,2′′-(1,3,5-benzinetriyl)-tris(1-phenyl-1-H-benzimidazole)(30nm)/8-hydroxyquinolinolato-lithium(2nm)/Al(120nm).WhitePHOLEDshows18.25cd/Aofluminousefficiencyandwhitecolorcoordinatesof(0.358and0.378)at5000cd/m2andcolorstabilitywithslightCIEXYchangeof(0.028and0.002)asincreasingluminancefrom1000to5000cd/m2.
简介:Thetransmissionpropertiesofone-dimensionalphotoniccrystalscontainingdouble-negativeandsingle-negativematerialsarestudiedtheoretically.Aspecialkindofphotonicbandgapisfoundinthisstructure.Thisgapisinvariantwithscalingandinsensitivetothicknessfluctuation.Butwhenchangingtheratioofthethicknessoftwomedia,thewidthofthegapcouldbeenlarged.Thedefectmodesareanalyzedbyinducingalineardefectlayerinthestructure.Itisfoundthatthenumberofdefectmodeswillincreasewhenthethicknessofthedefectlayerbecomeslarger.更多还原