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《退火溫度對同質(zhì)緩沖層ZnO薄膜微觀結(jié)構(gòu)和光學(xué)特性的影響.pdf》由會員上傳分享,免費在線閱讀,更多相關(guān)內(nèi)容在行業(yè)資料-天天文庫。
1、第48卷2012年第4期西北師范大學(xué)學(xué)報(自然科學(xué)版)Vo1.482012No.4JournalofNorthwestNormalUniversity(NaturalScience)27退火溫度對同質(zhì)緩沖層ZnO薄膜微觀結(jié)構(gòu)和光學(xué)特性的影響馬書懿,趙強(qiáng),靳鈺珉,馬李剛,張小雷,劉靜,楊付超,李發(fā)明(西北師范大學(xué)物理與電子工程學(xué)院,甘肅省原子分子與功能材料重點實驗室,甘肅蘭州730070)摘要:采用射頻磁控濺射法在300℃真空退火處理過的同質(zhì)緩沖層上制備了不同退火溫度下的ZnO薄膜.使用x射線衍射儀(XRD)和光致發(fā)光(PL)等表征技術(shù),研究
2、了ZnO薄膜的微觀結(jié)構(gòu)和發(fā)光特性.結(jié)果表明:在6rain緩沖層上制備的ZnO薄膜有較好的結(jié)晶質(zhì)量,并且在適當(dāng)?shù)耐嘶饻囟认卤∧さ慕Y(jié)晶質(zhì)量進(jìn)一步提高.薄膜在可見光范圍內(nèi)的平均透過率均超過9O,光學(xué)帶隙值隨退火溫度的增加由3.221eV減小為3.184eV.在光致發(fā)光譜(PL)中觀測到了5個主要的發(fā)光峰位,分別是紫外光(384nm)、紫光(420nm)、藍(lán)光(455nm和473nm)和綠光(530nm).對發(fā)光機(jī)制進(jìn)行詳細(xì)討論認(rèn)為,紫外光是自由激子復(fù)合形成的,紫光與晶界缺陷的輻射躍遷有關(guān),藍(lán)光與氧空位和間隙鋅缺陷有關(guān),綠光發(fā)射主要是電子從氧空位深
3、施主能級向鋅空位淺受主能級上的輻射躍遷.退火溫度從400℃增加到600℃時,455nm處的藍(lán)光峰藍(lán)移至447nm處,發(fā)光強(qiáng)度隨退火溫度增加而增加.繼續(xù)升高退火溫度至700℃,530nm處的綠光峰強(qiáng)度降低,認(rèn)為和鋅空位的減少有關(guān).關(guān)鍵詞:同質(zhì)緩沖層;Zn0薄膜;光致發(fā)光;輻射躍遷中圖分類號:0484.4;O484.5文獻(xiàn)標(biāo)識碼:A文章編號:1001-988X(2o12)04—0027-06Effectsofannealingtemperatureonstructuralandopticalpropertiesofhomo—bufferlaye
4、rZnOthinfilmsMAShu—yi,ZHAOQiang,JINYu—min,MALi—gang,ZHANGXiao—lei,LIUJing,YANGFu—chao,LIFa—ming(CollegeofPhysicsandElectronicEngineering,KeyLaboratoryofAtomicandMolecularPhysicsandFunctionalMaterialofGansuProvince,NorthwestNormalUniversity,Lanzhou730070,Gansu,China)Abstrac
5、t:Zn0thinfilmwasdepositedonSisubstratewiththeinsertionofZnObufferlayer,whichwasannealedat300℃invacuum.ZnOthinfilmwasgrownbyRFmagnetronsputteringdepositiontechniqueandtheZnO/ZnO—buffer/Sifilmshavebeenfurtherannealedwithdifferentannealingtemperatures.Themierostructureandlumi
6、nescencepropertiesofZnothinfilmswereinvestigatedbyX—raydiffraction(XRD)andphotoluminescence(PL)spectrum,respectively.Theresultsrevealthatthesample,whichwasgrownonbufferlayerofthedepositiontimeis6rain,hasthebestcrystallinequality.Thecrystallinequalityismarklyimprovedwithann
7、ealingtemperatureincreasing.Allfilmshaveanaverageopticaltransparencyover90%inthevisiblerange.Theopticalbandgapsgraduallydecreasefrom3.221eVto3.184eVwithintheincreaseofannealingtemperature.Fivemainpeakslocatedatabout384nm(UV),420nm(violet),455rim(blue),473nm(blue)and530nm(g
8、reen)photoluminescenceareobservedfromthePLspectra.TheUVemissioniSattributedtofreeexciton—