简介:ThepurecubicGaN(c-GaN)hasbeengrownon(001)GaAssubstratesbyECR-PAMOCVDtechniqueatlowtemperatureusingTMGaandhighpureN2asGaandNsources,respectively.TheeffectsofsubstratepretreatmentconditionsonqualityofcubicGaNepilayerareinvestigatedbythemeasurementsofTEMandXRD.Itisfoundthathydrogenplasmacleaning,nitridationandbufferlayergrowthareveryimportantforqualityofcubicGaNepilayer.
简介:Byusingspectroscopicphotoconductance,transmittanceandluminescencemethods,theopticalcharacterizationofGaNgrownbyplasmasourceMBEhavebeenevaluated.Theimperfectionoftheepitaxiallayerdeducedfromthemeasuredresultshavebeendiscussed.Thetransientresponsesofthephotoconductivedetectorshavebeenmeasured.Twotimeconstantsof0.17msand6.85msatroomtemperaturearededucedfromthemeasuredresults.Theoriginshavealsobeendiscussed.
简介:摘要:第三代半导体材料GaN器件以其开关速度快、临界电场高、高热导率等特点在新能源汽车、航空航天、电力电子和无线通信等领域发挥重要作用并被广泛应用,因此受到众多生产厂家关注并开始竞相研发和量产。开关器件在长时间高电压大电流状态下会承载较大的功率,面对突然的过压或过流都有可能导致开关器件过载而失效。因此,如何保证开关器件在特定条件范围内可靠地运行,安全工作区是一个重要的评判标准。本文以GaN器件为例,阐述功率半导体安全工作区的测试方法。同时因为SOA作为一种极限应力参数的实验,可能对板件造成不可修复的损坏,从而影响实验进度同时造成资源的浪费,本文提出一种新的实验方案同时设计新的实验电路板,在保证实验数据准确性的同时,满足可被测品易于更换,主电路板在被测品失效的条件下不受损坏的要求。
简介:Measurementsoftheexcitationpower-dependenceandtemperature-dependencephotoluminescence(PL)areperformedtoinvestigatetheemissionmechanismsofInGaN/GaNquantumwells(QWs)inlaserdiodestructures.ThePLspectralpeakisblueshiftedwithincreasingtemperatureoveracertaintemperaturerange.ItisfoundthattheblueshiftrangewaslargerwhenthePLexcitationpowerissmaller.ThisparticularbehaviorindicatesthatcarriersarethermallyactivatedfromlocalizedstatesandpartiallyscreenthepiezoelectricfieldpresentintheQWs.Thesmallblueshiftrangecorrespondstoaweakquantum-confinedStarkeffect(QCSE)andarelativelyhighinternalquantumefficiency(IQE)oftheQWs.
简介:TheenergybanddiagramandchargedistributionoftheunintentionaldopedAIGaN/GaN/AIGaN/GaNdoubleheterostructurewereobtainedbyself-consistentPoissonSchroedingercalculations.Theseverebandtiltingandhightwo-dimensionalelectrongas(2DEG)densitymainlyattributetothelargeinternalpolarizationintensity,whichisc/osetoalinearfunctionorAlcomposition.TheinfluenceorAlcompositionisinvestigated.Theresultsshowthatbandtiltingenlargesand2DEGgainswithAIcomposition,andtwo-dimensionalholegasoccurswhenAIcompositionreachesacertainextent.TheinfluenceorAlcompositionandtwo-dimensionalholegas(2DHG)ondevicesisdiscussed.
简介:调查在上植入Ge在氨下面轧了由MOCVD成年然后在1100点退火的电影周围被执行了。与增加Ge培植剂量,四座另外的山峰在260的波浪数字产生,314,428并且在Ramam系列的670cm-1。在PL系列,与在2.66eV和黄乐队集中的PL乐队相比的乐队边排放的相对紧张随植入Ge的剂量的增加减少。260的模式和314cm-1被归因于散布的激活混乱的拉曼,而428的模式和670cm-1被分到空缺和空缺相关的建筑群的本地颤动。在2.66eV和黄乐队集中的PL乐队也与这些空缺缺点有关。在为样品的301cm-1的新拉曼山峰退火了仅仅5min由于缺乏的退火从Ge簇发源。