AlGaN基深紫外發(fā)光二極管的光電熱特性研究

[33]。正向偏置下的隧穿電流IT與正向電壓VIe為電子電荷；IA為前指數(shù)因子常數(shù)，可以通過實驗或數(shù)值推導；Rseries為串聯(lián)電阻，ET為特征隧穿能量，表示界面能量勢壘的隧穿透過率根據(jù)該片參考文獻，本文可以大致推測使用三明治EBLs結(jié)構(gòu)，在小注入電流范圍內(nèi)，ET可達到121meV熱阻分析由圖5-10可知，芯片、AlN-DPCLF、AlMCPCB在積分曲線和微分曲線所處位置，并且粘黏劑AuSn、Cu具有極小的熱阻，驗證了其具有良好的導熱性。圖5-10275nmLED的熱阻積分曲線、微分曲線θ將熱阻值通過相關(guān)公式5-6，可以得出相關(guān)界面的溫度，并將其繪制成熱傳導模型，見圖5-11。在輸入功率為0.76W的熱阻分析中得到芯片、框架、印制電路板空氣的熱阻值分別為5.53、11.16、4.61、38.54℃/W。本文的AlN-DPCLF、AlMCPCB、空氣的理論熱阻值與相關(guān)材料的參考值對比，處于正常范圍內(nèi)。芯片的熱阻值已經(jīng)是在優(yōu)良的范圍內(nèi)，只比PCB大1℃/W。也側(cè)面驗證了本文探討的UV-LED缺陷密度極少。在通過計算可得知，在環(huán)境溫度為25℃時，結(jié)溫已經(jīng)達到了70.48℃，與圖5-4和5-8驗證了大部分的能量轉(zhuǎn)化成熱能，說明熱管理仍是未來需要繼續(xù)攻克的問題。圖5-11275nmLED的熱傳導模型由圖5-11可以看出AlN-DPCLF的熱阻值在整個熱傳導模型中(除空氣熱阻值外)是最大的，說明其熱傳導率相對較差。但本文探討UVC-LED的發(fā)光波長為275nm，在200~500nm的波長范圍內(nèi)，Al的反射系數(shù)最高，可以減少支架吸收紫外光，使更多的深紫外光可以輸出，所以選用見含Al的DPCLF，圖5-12。圖5-12Au、Al、Ag反射系數(shù)與波長的關(guān)系結(jié)論本文基于LP-MOCVD技術(shù)探討UVC-LED外延層設(shè)計，從減少UV-LED有源區(qū)缺陷程度的角度來改善275nmUV-LED的光電熱特性。實驗結(jié)果顯示UVC-LED得到一定程度的提升。主要實驗結(jié)果如下：使用XRD檢測①、②、③峰值，實驗結(jié)果顯示①、②、③衍射峰的強度高，F(xiàn)WHM分別為1.026、0.524、0.410Sec-1。說明其缺陷密度很小，晶體質(zhì)量很好。在光電特性實驗中，使用電致發(fā)光技術(shù)檢測整體發(fā)光情況，實驗結(jié)果顯示峰值波長具有較小的FWHM，并且工作溫度、電流均不會影響峰值波長的變化。并且在實驗條件下暫未出現(xiàn)寄生波或者紅移或者藍移的現(xiàn)象。在光電特性實驗中，LOP實驗結(jié)果說明在較大工作電流下，未出現(xiàn)輻射復(fù)合飽和情況。但LOP的斜率拐點與EQE下降拐點均在電流40mA，呈現(xiàn)輻射復(fù)合飽和的趨勢，側(cè)面驗證了位錯和雜質(zhì)含量較少；電流大于40mA后，參與非輻射復(fù)合的電子-空穴對占比逐漸增加。UV-LED的EQE實驗結(jié)果中，最大值為2.37%。說明本文探討的LED品質(zhì)屬于世界良好水平，并具有商業(yè)化的可能與價值。在室溫25℃的熱阻特性測試中，芯片結(jié)溫達到70.48℃，芯片、框架、印制電路板、空氣的熱阻值分別為5.53、11.16、4.61、38.54℃/W。存在超過芯片承載溫度使發(fā)光效率快速降低、損壞芯片的可能。ADDINNE.Bib[參考文獻]SilveiraE,FreitasJA,GlembockiOJetal.ExcitonicstructureofbulkAlNfromopticalreflectivityandcathodoluminescencemeasurements[J].Phys.Rev.B,2005,71(4):41201BhuiyanAG,SugitaK,KasashimaK,etal.Single-crystallineInNfilmswithanabsorptionedgebetween0.7and2eVgrownusingdifferenttechniquesandevidenceoftheactualbandgapenergy[J].AppliedPhysicsLetters,2004,84(23):452-452.HaldarS,SenD.Onthebandgapofindiumnitride[J].physicastatussolidi(b),2003:439-447.Nakamura,Shuji.InGaN/AlGaNblue‐light‐emittingdiodes[J].JournalofVacuumScience&TechnologyAVacuumSurfaces&Films,1995,13(3):705-710.NakamuraS.InGaN-basedbluelaserdiodes[J].IEEEJournalofSelectedTopicsinQuantumElectronics,1997,3(3):712-718.JaniO,FergusonI,HonsbergC,etal.DesignandcharacterizationofGaN∕InGaNsolarcells[J].AppliedPhysicsLetters,2007,91(13):1-20.KhanMA,KuzniaJN,OlsonDT,etal.SchottkybarrierphotodetectorbasedonMg-dopedp-typeGaNfilms[J].AppliedPhysicsLetters,1993,63(18):2455-2456.譚斐,楊映霞.廣西地面太陽輻射分布特征以及對人體健康的影響S14[C]//中國氣象學會.中國氣象學會,2011.ChatterleyC,LindenR.DemonstrationandevaluationofgermicidalUV-LEDsforpoint-of-usewaterdisinfection.[J].JournalofWaterandHealth,2010,8(3):479-486.Honigsmann,H.Historyofphototherapyindermatology[J].Photochemical&PhotobiologicalSciences,2013.FowlesM,WayneRP.OzonemonitorusinganLEDsource[J].J.phys.eInstrum,1981,14(10):1143.G.Wiegleb.EinsatzvonLED-StrahlungsquelleninAnalysenger?ten.LaserundOptoelektronik3,308–3110(1985)KneisslM,YangZ,TeepeM,etal.UltravioletInAlGaNLightEmittingDiodesGrownonHydrideVaporPhaseEpitaxyAlGaN/SapphireTemplates[J].JapaneseJournalofAppliedPhysics,2006,45(5A):3905-3908.KusanoM,TohgeT,FukushimaA,etal.MetabolomicsrevealscomprehensivereprogramminginvolvingtwoindependentmetabolicresponsesofArabidopsistoUV-Blight[J].ThePlantJournal,2011,67(2):354-369.Nam,K.B,Li,etal.UniqueopticalpropertiesofAlGaNalloysandrelatedultravioletemitters.[J].AppliedPhysicsLetters,2004,84(25):5264.KolbeT,KnauerA,ChuaC,etal.Opticalpolarizationcharacteristicsofultraviolet(In)(Al)GaNmultiplequantumwelllightemittingdiodes[J].AppliedPhysicsLetters,2010,97(17):171105-171105-3.RyuHY,ChoiIG,ChoiHS,etal.InvestigationofLightExtractionEfficiencyinAlGaNDeep-UltravioletLight-EmittingDiodes[C]//Lasers&Electro-opticsPacificRim.2013.FYun,ReshchikovMA,HeL,etal.EnergybandbowingparameterinAlxGa1-xNalloys[J].JournalofAppliedPhysics,2002,92(8):4837-4839.ChichibuSF,AbareAC,MinskyMS,etal.EffectivebandgapinhomogeneityandpiezoelectricfieldinInGaN/GaNmultiquantumwellstructures[J].AppliedPhysicsLetters,1998,73(14):2006-2008.MillerD,ChemlaDS,DamenTC,etal.Band-EdgeElectroabsorptioninQuantumWellStructures:TheQuantum-ConfinedStarkEffect[J].PhysicalReviewLetters,1984,53(22):2173--2176.程文進,鞏小亮,陳峰武,彭立波,魏唯.高溫MOCVD外延生長AlN材料研究[J].電子工業(yè)專用設(shè)備,2017,46(04):43-49.EsakiL,TsuR.Superlatticeandnegativedifferentialconductivityinsemiconductors[J].IBMJ.Res.Dev.,1970,14(1):61~65ZhangJP,WangHM,GaevskiMEetal.Crack-freethickAlGaNgrownonsapphireusingAIN/AlGaNsuperlatticesforstrainmanagement[J].AppliedPhysicsLetters,2002,80(19):3542-3544.WangHM,ZhangJP,ChenCQ,etal.AlN/AlGaNsuperlatticesasdislocationfilterforlow-threading-dislocationthickAlGaNlayersonsapphire[J].AppliedPhysicsLetters,2002,81(4):604-606.李洋.AlGaN基深紫外LED的MOCVD外延生長[D].華中科技大學,2015.MukaiT,NakamuraS.UltravioletInGaNandGaNSingle-Quantum-Well-StructureLight-EmittingDiodesGrownonEpitaxiallyLaterallyOvergrownGaNSubstrates[J].JapaneseJournalofAppliedPhysics,1999,38(Part1,No.10):5735-5739.C.H.Wang,C.C.Ke,C.Y.Lee,S.P.Chang,W.T.Chang,J.C.Li,Z.Y.Li,H.C.Yang,H.C.Kuo,T.C.Lu,andS.C.Wang.HoleinjectionandefficiencydroopimprovementinInGaN/GaNlight-emittingdiodesbyband-engineeredelectronblockinglayer[J].AppliedPhysicsLetters,2010,97(26):183507.ZhangL,WeiXC,LiuNX,etal.ImprovementofefficiencyofGaN-basedpolarization-dopedlight-emittingdiodesgrownbymetalorganicchemicalvapordeposition[J].AppliedPhysicsLetters,2011,98(24):101110.KuoYK,ChenJY,TsaiMC.Enhancementinhole-injectionefficiencyofblueInGaNlight-emittingdiodesfromreducedpolarizationbysomespecificdesignsfortheelectronblockinglayer[J].OpticsLetters,2010,35(19):3285-3287.ZhangYY，YinYA.Performanceenhancementofbluelight-emittingdiodeswithaspecialdesignedAlGaNV/GaNsuper-latticeelectron-blockinglayer[J].Appl.Phys.Lett.,2011,99(22):2211031-3章敏杰,梅霆,王乃印,朱凝,王達飛,李浩,文潔.三明治結(jié)構(gòu)電子阻擋層中勢阱深度對LED性能的影響[J].發(fā)光學報,2013,34(10):1367-1372.蔣建華,黃慧詩,梁紅偉,王東盛,柳陽,夏曉川,申人升.不同電子阻擋層的紫光LED特性研究[J].光電子技術(shù),2015,35(04):253-257+262.DOI:10.19453/ki.1005-488x.2015.04.008.K.B.Lee,P.J.Parbrook,P.J.Parbrook,T.Wang,J.Bai,F.Ranalli,R.J.Airey,G.Hill.TheoriginofthehighidealityfactorinAlGaN-basedquantumwellultravioletlightemittingdiodes[J].physicastatussolidi(b)basicsolidstatephysics.Volume247,Issue7.July2010(1761-1763)崔文龍.GaN基紫光LEDITO透明電極透光率優(yōu)化的研究[D].西安電子科技大學,2016.盛彬彬,王玲,許金通,李向陽.利用AlGaN薄膜透射譜提取材料參數(shù)的研究[J].光學學報,2021,41(03):152-159.洪靈愿,劉寶林.AlN/GaN分布布拉格反射器反射率的研究[J].集美大學學報(自然科學版),2005(02):164-168.李晉閩,王軍喜,閆建昌等.氮化物深紫外發(fā)光材料及器件[M].科學出版社,2021.俞曉東.大功率LED燈用敷銅陶瓷基板的制備及性能研究[D].南京航空航天大學,2011.T.-Y.Liuetal.,EpoxyMoldingCompoundLeadFramesWithSiliconeResinforEncapsulatingAlGaN-BasedUVBLight-EmittingDiodes[J].IEEEAccess,vol.9,pp.129874-129880,2021,doi:10.1109/ACCESS.2021.3111258.Lai,M.-J.,Liu,R.-S.,Liu,T.-Y.,Huang,S.-M.,Lin,R.-M.,Chang,Y.-T.,Wu,J.-B.,Sun,W.-H.,Zhang,X.,Chen,L.-C.ObservationofHighlyDurableSiliconeResinforEncapsulatingAlGaN-BasedUVBLight-EmittingDiodes[J].AppliedSciences11,9278..doi:10.3390/app11199278WuT,LinY,PengZ,etal.Interplayofcarriersanddeep-levelrecombinationcentersof275-nmlight-emittingdiodes—Analysisontheparasiticpeaksoverwiderangesoftemperatureandinjectiondensity[J].OpticsExpress,2019,27(16):A1060.PerlinP,Osin?SkiM,EliseevPG,etal.Low‐temperaturestudyofcurrentandelectroluminescenceinInGaN/AlGaN/GaNdouble‐heterostructurebluelight‐emittingdiodes[J].AppliedPhysicsLetters,1996,69(12):1680-1682.X.A.Cao,J.M.Teetsov,M.P.D'Evelyn,D.W.Merfeld,and