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热氧化制备纳米氧化锌薄膜的光致发光和室温紫外激光发射 总被引:8,自引:2,他引:6
利用低压 -金属有机汽相外延 (L P- MOCVD)工艺首先在二氧化硅衬底上生长硫化锌 (Zn S)薄膜 ,然后 ,将硫化锌薄膜在氧气中于不同温度下进行热氧化 ,制备出高质量的纳米氧化锌 (Zn O )薄膜 .X射线衍射 (XRD)结果表明 ,氧化锌具有六角纤锌矿晶体结构 .90 0℃氧化样品的光致发光 (PL )谱中 ,在波长为 3.3e V处观察到一束强紫外光致发光和相当弱的深能级发射 .紫外发光强度与深能级发射强度之比是 80 ,表明纳米 Zn O薄膜的高质量结晶 .在受激发射实验中观察到紫外激光发射 . 相似文献
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固体源化学气相沉积生长c轴平行于衬底的ZnO薄膜 总被引:14,自引:7,他引:7
报道了利用固体源化学气相沉积 (SS- CVD)技术制备出 c轴平行于衬底的 Zn O薄膜 .固体 Zn(CH3COO) 2 ·2 H2 O为前驱体 ,在不同的生长条件沉积 Zn O薄膜 ,并利用 X射线衍射 (XRD)、原子力显微镜 (AFM)、光学透射谱对其性能进行研究 .结果表明 ,在玻璃衬底上 ,当衬底温度较低 (2 0 0℃ )、源温较高 (2 80℃ )时 ,Zn O薄膜呈 (10 0 )与(110 )的混合取向 ,即 c轴平行于衬底 .对此 ,文中给出了一个可能的定性解释 .AFM测试表明薄膜表面平整度不够理想 ,该薄膜在可见光区域透射率为 85 % ,光学带宽约为 3.2 5 e V. 相似文献
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ZnAl_2O_4/α-Al_2O_3衬底上GaN的生长 总被引:1,自引:0,他引:1
研究了直接在 Zn Al2 O4/α-Al2 O3 衬底上用 MOCVD法一步生长 Ga N薄膜 .利用脉冲激光淀积法在α-Al2 O3衬底上淀积了高质量 Zn O薄膜 ,对 Zn O/α-Al2 O3 样品在 110 0℃退火得到了具有 Zn Al2 O4覆盖层的 α-Al2 O3 衬底 ,并在此复合衬底上利用光加热低压 MOCVD法直接生长了纤锌矿结构 Ga N. X射线衍射谱表明反应得到的Zn Al2 O4层为 ( 111)取向 .扫描电子显微镜照片显示随退火时间从小于 3 0 min增加到 2 0 h,Zn Al2 O4表面由均匀的岛状结构衍变为突起的线状结构 ,相应的 Ga N X射线衍射谱表明 Ga N由 c轴单晶变为多晶 ,单晶 Ga N的摇摆曲线半高宽 相似文献
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脉冲激光沉积法制备氧化锌薄膜 总被引:7,自引:0,他引:7
ZnO是一种新型的Ⅱ-Ⅵ族半导体材料,具有优良的晶格、光学和电学性能,其显著的特点是在紫外波段存在受激发射。利用脉冲激光沉积法(PLD)在氧气氛中烧蚀锌靶制备了纳米晶氧化锌薄膜,衬底为石英玻璃,晶粒尺寸约为28-35 nm。X射线衍射(XRD)结果和光致发光(PL)光谱的测量表明,当衬底温度在100-250℃范围内时,所获得的ZnO薄膜具有c轴的择优取向,所有样品的强紫外发射中心均在378-385 nm范围内,深能级发射中心约518-558 nm,衬底温度为200℃时,得到了单一的紫外光发射(没有深能级发光)。这归因于其较高的结晶质量。 相似文献
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Sun-Hong Park Chul-Hwan Choi Kyoung-Bo Kim Seon-Hyo Kim 《Journal of Electronic Materials》2003,32(11):1148-1154
High-quality ZnO thin films were prepared by metal-organic chemical vapor deposition (MOCVD) on a sapphire (a-Al2O3) substrate. The synthesis of ZnO films was performed over a substrate temperature of 400–700°C and at chamber pressures of
0.1–10 torr. The structural and optical properties of ZnO films were investigated in terms of deposition conditions, such
as substrate temperature, working pressure, and the ratio of Zn precursor (Diethylzinc (DEZn)) to oxygen. The ZnO films, preferentially
oriented to 34.42° diffraction because of the (002) plane, were obtained under processing conditions of 700°C and 3 torr.
This film shows a full-width at half-maximum (FWHM) of 0.4–0.6°. The results of photoluminescence (PL) spectroscopy also show
a strong near band-edge emission at 3.36 eV at 10 K as well as a very weak emission at deep levels around 2.5 eV at room temperature.
In addition, we are interested in the introduction of ZnO buffer-layer growth by the sputtering process to reduce lattice
mismatch stress. This paper addresses how to advance the crystalline and optical properties of film. The ZnO film grown with
the aid of a buffer layer shows a FWHM of 0.06–0.1° in the x-ray diffraction (XRD) pattern. This result indicates that crystalline
properties were highly improved by the ZnO buffer layers. The PL spectroscopy data of ZnO film also shows a strong near band-edge
emission and very weak deep-level emission similar to films synthesized without a buffer layer. Accordingly, synthesized ZnO
films with buffer layers indicate fairly good optical properties and low defect density as well as excellent crystallinity. 相似文献
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利用ZnO微晶粉末以化学电泳法成功地在导电玻璃上制备了不同x值的紫外发光的宽禁带氧化物半导体三元化合物MgxZn1-xO薄膜.电子显微镜和X 射线衍射研究显示,薄膜由MgxZn1-xO微晶组成,薄膜中微晶大小的分散度比ZnO粉末有所减小,并更具择优取向的趋势.室温下光致发光测量给出,MgxZn 1-xO薄膜在小于380nm的紫外波段出现较强的半宽小于20nm的激子性发光峰,而且带边峰的半宽以及带边峰与杂质缺陷峰强度之比均较原始的ZnO粉末有明显改善,表明这种MgxZn1-xO薄膜具有优良的紫外发光特性. 相似文献
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用脉冲激光沉积(PLD)方法在Si(111)和蓝宝石衬底上制备的氧化锌薄膜,在不同的退火温度和不同的退火氛围中进行了退火处理.退火温度及退火氛围对ZnO薄膜的结构和发光特性的影响用X射线衍射(XRD)谱和光致发光谱进行了表征.实验结果表明,随着退火温度的提高,ZnO薄膜的压应力减小,并向张应力转化.在不同的退火温度退火... 相似文献
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在Si(111)衬底上利用等离子体辅助分子束外延(P-MBE)生长氧化锌(ZnO)薄膜,研究了在不同衬底生长温度下(350~750℃)制备的ZnO薄膜的结构和光学性质.随着衬底温度的升高,样品的X射线及光致发光的半高宽度都是先变小后变大,衬底温度为550℃样品的结构及光学性质都比较好,这表明550℃为在Si(111)衬底上生长ZnO薄膜的最佳衬底温度;同时,我们还通过550℃样品的变温光致发光谱(81~300K)研究了ZnO薄膜室温紫外发光峰的来源,证明其来源于自由激子发射. 相似文献
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In this paper the effects of silicon substrates with different orientations on the morphological and optical properties as well as biaxial stress of ZnO nanowires were investigated. The ZnO nanowires were grown on Si(1 0 0) and Si(1 1 1) substrates by the vapor–solid (VS) method using a physical vapor deposition reactor. In addition ZnO nanowires were grown on Si(1 1 1) substrate by the vapor–liquid–solid (VLS) method using an Au film as catalyst, which were deposited on Si(1 1 1) substrate using a sputtering method, with the same conditions. Room temperature photoluminescence (PL) spectrum showed a stronger ultraviolet (UV) peak at 381 nm for the nanowires that were grown on Si(1 1 1) by the VS method than those that were grown on Si(1 0 0) with the same green emission (deep-level emission (DLE)) intensities at about 520 nm peak. On the other hand, the PL result of the ZnO nanowires, which were grown by the VLS method, showed the same intensities for the both UV and DLE peaks. Furthermore, the effects of silicon substrate orientation and Au catalyst on biaxial stress of the nanowires were studied by Raman spectrometer. It was discussed that Au catalyst was one of the important factors that could affect the biaxial stress value of the ZnO nanowires that were grown on Si substrates. 相似文献
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The properties of ZnO thin film on sapphire (0001) substrate fabricated by single source chemical vapour deposition (SSCVD) method are studied. X-ray diffraction (XRD) analysis demonstrates that the film exhibits hexagonal structures but with preferential nonpolar (100) plane orientation, which is different from the crystalline structure of substrate, and its formation mechanism is also analyzed. The film has the characteristic of p-type conductivity originating from excess of oxygen, and its p-type conductivity is comparatively stable due to its nonpolar plane orientation. A strong ultraviolet (UV) emission and a high light transmission in visible wavelength region are observed from photo-luminescence (PL) spectrum and transmittance spectra at the room temperature, and the strong ultraviolet emission originates from the recombination of free and bound excitons. Compared with the ZnO film on silicon substrates, the exciton emission peaks of the film on sapphire substrate show a slight blue shift about 50 meV, which might be related to the different crystallite sizes or surface stress of the films. 相似文献
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在从室温到800℃的温度范围内,用脉冲激光沉积方法在Al2O3(0001)衬底上制备了ZnO薄膜。采用X射线衍射仪、原子力显微镜以及荧光光谱仪分别研究了衬底温度对ZnO薄膜表面形貌、结晶质量和光致发光特性的影响。X射线衍射仪和原子力显微镜的结果表明,当衬底温度从室温升高到400℃时,ZnO薄膜的结构及结晶质量逐渐提高,而当衬底温度超过400℃时,其结构和结晶质量变差;在400℃下生长的ZnO薄膜具有最佳的表面形貌和结晶质量。室温光致发光的测量结果表明,400℃下生长的ZnO薄膜的紫外发光强度最强,且发光波长最短(386 nm)。 相似文献
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研究了暴露在空气中退火和表面覆盖蓝宝石基板退火对MOCVD生长的ZnO薄膜光学性质的影响.研究发现,暴露在空气中退火虽可以去除薄膜中的氢杂质,并在低温光致发光(PL)谱中观察到与氢相关的束缚激子峰消失,但是退火后样品室温PL谱中可观察到很强的可见光发射,表明样品中引入了大量的深能级,样品的自由激子发光没有增强.而表面覆盖蓝宝石基板退火的样品,有效去除了氢杂质,但没有观察到可见光发射,说明表面覆盖蓝宝石基板退火可以有效地保护ZnO表面不分解,不生成深能级中心.由于激子束缚中心的减少,表面覆盖退火样品的自由激子发射大大增强. 相似文献