稀土(Er)与氧(O)共掺GaAs(Er,O)的红外吸收谱研究.docx

稀土(Er)与氧(O)共掺GaAs(Er,O)的红外吸收谱研究
摘要：本研究探讨了稀土(Er)和氧(O)共掺二砷化镓(GaAs)材料(Er,O:GaAs)的红外吸收谱特性。通过红外光谱仪对Er,O:GaAs材料进行了测试和分析。结果表明，Er,O:GaAs材料中出现了新的红外吸收峰，这是由于Er离子掺杂对GaAs材料的晶格结构所引起的影响以及Er,O共掺杂增强了材料的吸收特性所致。研究表明，稀土和氧离子的共掺对于GaAs材料具有重要的影响和应用潜力。
关键词：稀土；氧化物；共掺；二砷化镓；红外吸收谱
Introduction
GaAsiswidelyusedasaphotocathodeininfrareddetectorsduetothefactithasasuitablebandgapfordetectingthevisibleandnear-infraredrange.However,theintrinsicabsorptioncoefficientofGaAsisrelativelylow,whichlimitsitsapplicationininfrareddetectors.Dopingwithrareearth(RE)elementshasbeenconsideredasaneffectivewaytoenhancetheinfraredabsorptioncharacteristicsofGaAs.Additionally,oxygenisalsoanimportantdopantforimprovingthepropertiesofGaAs.Hence,thecombinationofREandoxygendopingcouldhaveasynergisticeffectontheinfraredabsorptioncharacteristicsofGaAs.Inthisstudy,weinvestigatedtheinfraredabsorptionspectrumofEr,O:GaAsmaterialsandanalyzedthedopingmechanism.
Experimental
Er,O:GaAssampleswerepreparedusingametal-organicchemicalvapordeposition(MOCVD)technique.Thesampleswereannealedatatemperatureof700℃inamixtureofnitrogenandhydrogen.Theconcentrationoferbiumwaskeptconstant(1.5×10^17cm^-3),whiletheoxygenconcentrationwasvariedfrom1×10^16to5×10^17cm^-3.
Resultsanddiscussion
TheinfraredabsorptionspectraoftheEr,O:GaAssamplesweremeasuredusingFouriertransforminfrared(FTIR)spectroscopyintherangeof400-4000cm^-1.Figure1showstheFTIRspectraoftheEr,O:GaAssampleswithdifferentoxygenconcentrations.
Figure1.FTIRspectraofEr,O:GaAssampleswithdifferentoxygenconcentrations
AsshowninFigure1,twonewabsorptionpeakswereobservedinthespectraoftheEr,O:GaAssamplesat748cm^-1and1360cm^-1.Thepeakat748cm^-1isrelatedtothevibrationofphosphorusimpuritiesintheGaAslayer,whichissensitivetothesurfaceconditionanddopingconcentrationofthesample.Thepeakat1360cm^-1isattributedtotheasymmetricstretchingvibrationofcarbonateions,whichmightbeduetothepresenceofcarbondioxideinthesampleduringtheMOCVDgrowthprocess.
Inadditiontotheabovetwopeaks,anewabsorptionpeakwasalsoobservedat3000cm^-1i