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1.
不同衬底温度下PLD法制备的氧化锌薄膜的特性 总被引:1,自引:1,他引:0
利用GCR-170型脉冲激光器Nd:YAG的三次谐波(355nm),以蓝宝石Al2O3(0001)为衬底,在不同温度下采用脉冲激光沉积法制备了ZnO薄膜.通过原子力显微镜、Raman谱、光致发光谱、红外透射谱、霍尔效应和表面粗糙度分析仪对制备的ZnO薄膜进行了测试.分析了在不同衬底温度下薄膜的表面形貌、光学特性,同时进行了薄膜结构和厚度的测试.研究表明:衬底温度对ZnO薄膜的表面形貌、光学特性、结构特性都是重要的工艺参量,尤其在500℃时沉积的ZnO薄膜致密均匀,并表现出较强的紫外发射峰. 相似文献
2.
采用脉冲激光法(PLD)在Si衬底上沉积Zn1-xMgxO薄膜.x射线衍射(XRD)表明薄膜为c轴取向,(002)峰的半高宽仅为0.211°,且没有MgO的相偏析.透射电子显微镜可以清楚看到Zn1-xMgxO薄膜的c轴择优取向.在选区电子衍射图中可以看到Zn1-xMgxO结晶薄膜整齐的衍射斑点.室温下对Zn1-xMgxO薄膜进行了光致荧光光谱分析,发现其带边发射峰相对ZnO晶体有0.4eV的蓝移,带边发射峰与杂质发射峰的强度之比高达159.Zn1-xMgxO结晶薄膜质量良好,显示了应用于光电器件的潜力.
关键词:
Zn1-xMgxO合金薄膜
硅衬底
脉冲激光沉积法
c轴取向
光致荧光光谱 相似文献
3.
采用反应射频磁控溅射方法,在Si (100) 基片上制备了具有高c轴择优取向的ZnO薄膜.利用 原子力显微镜、透射电子显微镜、X射线衍射分析、拉曼光谱等表征技术,研究了沉积温度 对ZnO薄膜的表面形貌、晶粒尺度、应力状态等结晶性能的影响;通过沉积温度对透射光谱 和光致荧光光谱的影响,探讨了ZnO薄膜的结晶特性与光学性能之间的关系.研究结果显示, 在室温至500℃的范围内,ZnO薄膜的晶粒尺寸随沉积温度的增加而增加,在沉积温度为500 ℃时达到最大;当沉积温度为750℃时,ZnO薄膜的晶粒尺度有所减小;在室温至750℃的范 围内,薄膜中ZnO晶粒与Si基体之间均存在着相对固定的外延关系;在沉积温度低于500℃时 ,制备的ZnO薄膜处于压应变状态,而750℃时沉积的薄膜表现为张应变状态.沉积温度的不 同导致ZnO薄膜的折射率、消光系数、光学禁带宽度以及光致荧光特性的变化,沉积温度对 紫外光致荧光特性起着决定性的作用.此外,探讨了影响薄膜近紫外光致荧光发射的可能因 素.
关键词:
ZnO薄膜
表面形貌
微观结构
光学常数 相似文献
4.
分别采用直流反应溅射法和脉冲激光沉积法在硅衬底上沉积ZnO薄膜, 用X射线衍射、扫描电镜、光致发光谱等手段对两种方法沉积的ZnO薄膜的结晶状态、 表面形貌和光致发光等进行了表征. 进一步对比研究了以上述两种方法制备的ZnO薄膜作为发光层的金属-绝缘体-半导体结构器件的电抽运紫外随机激射. 结果表明, 与以溅射法制备的ZnO薄膜作为发光层的器件相比, 以脉冲激光沉积法制备的ZnO薄膜为发光层的器件具有更低的紫外光随机激射阈值电流和更高的输出光功率. 这是由于脉冲激光沉积法制备的ZnO薄膜中的缺陷更少, 从而显著地减少了紫外光在光散射过程中的光损耗.
关键词:
随机激射
ZnO薄膜
脉冲激光沉积
溅射 相似文献
5.
《发光学报》2017,(7)
利用脉冲激光沉积(PLD)设备在蓝宝石衬底上制备了高质量Zn_(1-x)Mg_xO单晶薄膜,并对其结构和光学特性进行了深入细致的研究。通过能量衍射谱(EDS)确认Zn_(1-x)Mg_xO薄膜的Mg组分为45%。在Zn0.55Mg0.45O薄膜的X射线衍射谱(XRD)中观测到了明显的位于36.67°的衍射峰,对应的是(111)晶向的立方相ZnMgO。从透射光谱中可以看出,Zn0.55Mg0.45O具有陡峭的吸收边,没有发生相分离,在透射电镜图谱中也得到了证实。该ZnMgO薄膜还表现出了优异的光学特性,在Zn0.55Mg0.45O材料体系中实现了峰位位于310 nm的紫外光泵浦受激发射,其激光发射的阈值仅为22 k W/cm2。 相似文献
6.
用MOCVD方法在c面蓝宝石衬底上生长ZnO薄膜。生长前衬底表面进行预处理,观察不同表面预处理对ZnO薄膜质量的影响。测量氧化锌的XRD谱,观察表面预处理后对氧化锌薄膜结晶质量的影响。室温下用325nm的He-cd激光器作为激发源测量ZnO薄膜的紫外发光谱,观察表面处理后对ZnO薄膜发光特性的影响。用HL5500 Hall System分别对ZnO薄膜的电学特性进行了测试。得到了ZnO薄膜的电阻率和霍尔迁移率,并得到氧气气氛处理后电阻率变小,霍尔迁移率变大;氮气气氛射频处理后电阻率变大,霍尔迁移率变小的结果。 相似文献
7.
利用脉冲激光沉积(PLD)设备在蓝宝石衬底上制备了高质量Zn1-xMgxO单晶薄膜,并对其结构和光学特性进行了深入细致的研究。通过能量衍射谱(EDS)确认Zn1-xMgxO薄膜的Mg组分为45%。在Zn0.55Mg0.45O薄膜的X射线衍射谱(XRD)中观测到了明显的位于36.67°的衍射峰,对应的是(111)晶向的立方相ZnMgO。从透射光谱中可以看出,Zn0.55Mg0.45O具有陡峭的吸收边,没有发生相分离,在透射电镜图谱中也得到了证实。该ZnMgO薄膜还表现出了优异的光学特性,在Zn0.55Mg0.45O材料体系中实现了峰位位于310 nm的紫外光泵浦受激发射,其激光发射的阈值仅为22 kW/cm2。 相似文献
8.
针对目前关于退火温度对原子层沉积法(ALD)制备ZnMgO薄膜晶体结构和光学性质影响鲜有报道的现象,进行了相应的实验研究分析。采用ALD在石英衬底上制备ZnMgO合金薄膜,对制得的样品在空气中进行不同温度的退火处理。利用X射线多晶衍射仪(XRD)、光致发光谱(PL)和紫外可见(UV-Vis)吸收光谱测试,系统的分析了不同退火温度对ALD法制备ZnMgO薄膜晶体结构和光学性能的影响。XRD测试结果表明:退火温度为600 ℃时,薄膜的晶体质量得到改善,且(100)衍射峰的强度明显增强。结合PL和UV-Vis吸收光谱的测试分析得出:退火温度为600 ℃时,能明显促进薄膜中Mg组分的增加使薄膜的禁带宽度进一步增大。从而说明适当温度的退火处理可有效的改善ZnMgO薄膜的晶体质量及光学特性。 相似文献
9.
使用脉冲激光沉积(PLD)方法在石英(SiO2)和单晶Si(111)基底上制备了具有高c轴择优取向的ZnO薄膜。测试结果显示:在30~70sccm氧气流量范围内,氧气流量50sccm时制备的ZnO薄膜具有较好的结晶质量、较高的光学透过率(≥80%)、较高的氧含量(~40.71%)、较快的生长速率(~252nm/h)和较好的发光特性:450~580nm附近发射峰最弱,同时~378nm附近的紫外发光峰最强,表明薄膜材料中含有较少的氧空位等缺陷。 相似文献
10.
11.
J. Xu J.S. Thakur G. Hu Q. Wang Y. Danylyuk H. Ying G.W. Auner 《Applied Physics A: Materials Science & Processing》2006,83(3):411-415
AlN thin films have been grown on a-plane sapphire (Al2O3(112̄0)) substrates. X-ray diffraction measurements indicate the films are fully c-plane (0001) oriented with a full width at half maximum of the AlN(0002) rocking curves of 0.92. The epitaxial growth relationships
have been determined by the reflection high energy electron diffraction analysis as AlN[11̄00]//Al2O3[0001] and AlN[112̄0]//Al2O3[11̄00]. Angular dependence of important surface acoustic wave (SAW) characteristics, such as the phase velocity and electromechanical
coupling coefficient, has been investigated on the AlN(0001)/Al2O3(112̄0) structure. While the SAW is excited at all propagation angles with an angular dispersion of the phase velocity in
the range of 5503–6045 m/s, a higher velocity shear-horizontal (SH) mode is observed only at 0°, 105° and 180° off the reference
Al2O3[11̄00] over a 180° angular period. The phase velocity of the SH mode shows dispersion (6089–6132 m/s) as a function of the
SAW wavelength. Temperature coefficients of frequency are also demonstrated for both modes.
PACS 81.15.Hi; 77.84.-s; 77.65.Dq 相似文献
12.
测量了在不同氧压下退火生长的YBa2Cu3O7-x(YBCO)薄膜中的激光感生热电电压(LITV)信号,发现随退火氧压的增大可使LITV信号的峰值有2—4倍的增强,并且变化趋势与薄膜热电势的各向异性随氧含量的变化规律相同.波长在473—808nm范围内的连续激光辐照,在5000Pa的氧压下退火生长的YBCO薄膜中探测到的LITV信号最大;而紫外脉冲激光辐照时,LITV信号的最大值出现在退火氧压为105Pa
关键词:
2Cu3O7-x薄膜')" href="#">YBa2Cu3O7-x薄膜
激光感生热电电压
各向异性的Seebeck系数
氧含量 相似文献
13.
E. Popova H. Ndilimabaka B. Warot-Fonrose M. Bibes N. Keller B. Berini F. Jomard K. Bouzehouane Y. Dumont 《Applied Physics A: Materials Science & Processing》2008,93(3):669-674
The understanding and control of the ilmenite–hematite solid solutions (Fe2−x
Ti
x
O3±δ
or IH) thin film structure and properties are crucial for spintronics applications. Good quality films of Fe2−x
Ti
x
O3±δ
on Al2O3(0001) substrates were obtained by pulsed laser deposition. For the studied compositions (x=1, 0.7, 0.5) in a wide oxygen pressure range all the films were epitaxial, with flat interfaces, and without secondary phases.
Unconventional lattice strain relaxation with the increase of in-plane lattice parameter above its relaxed bulk value was
observed for different film compositions, oxygen pressures, substrate temperatures, and film growth rates. This phenomenon
is most likely explained by the buckling of a few first film monolayers because of a significant compressive stress induced
on the film by the sapphire substrate. The IH thin films with x=0.7 and 0.5 exhibited the properties of a room temperature magnetic semiconductor. The resistivity changed over three orders
of magnitude in the studied pressure range, thus clearly demonstrating the important role of oxygen stoichiometry in the creation
of carriers. 相似文献
14.
The synthesis of epitaxial Al2O3 films by oxidizing AlN/sapphire(0001) films was investigated in a synchrotron X-ray scattering experiment. Porous Al2O3 nucleates on the surface of the AlN film when annealed above 700 °C in oxygen ambient. As the annealing temperature increases above 900 °C, the entire AlN film is oxidized into an epitaxial Al2O3 film that has a cubic spinel structure. With increasing oxidation temperature, more oxygen atoms are incorporated into the oxide structure, resulting in denser oxide films with a larger lattice constant. The crystal domain size increases from 50 Å to 210 Å, suggesting that the initial nucleation of the Al2O3 crystalline domains is followed by gradual grain growth. PACS 61.10.Eq; 81.65.Mq; 68.55.Jk; 68.35.Ct 相似文献
15.
采用脉冲激光沉积技术制备了SrTiO3和SrNb0.2Ti0.8O3薄膜.X射线衍射分析表明在LaAlO3(100)单晶平衬底上生长的SrTiO3及SrNb0.2Ti0.8O3薄膜是沿[001]取向的近外延生长.随着氧压在一定范围内逐渐增大,SrTiO3薄膜的晶格参数减小,而SrNb0.2Ti0.8O3薄膜的晶格参数先减小后增大.同时摸索出制备具有二维电子气超晶格(SrTiO3/SrNb0.2Ti0.8O3)L的最佳氧压为1.0×10-2Pa.另外在LaAlO3(100)倾斜衬底上制备的SrNb0.2Ti0.8O3薄膜中观察到激光感生热电电压效应.
关键词:
0.2Ti0.8O3薄膜')" href="#">SrNb0.2Ti0.8O3薄膜
晶格参数
激光感生热电电压
脉冲激光沉积 相似文献
16.
《Current Applied Physics》2014,14(5):744-748
Raman scattering spectroscopy has been performed on high quality Co-doped ZnO epitaxial films, which were grown on Al2O3 (0001) by oxygen-plasma assisted molecular beam epitaxy. Raman measurements revealed two local vibration modes (LVMs) at 723 and 699 cm−1 due to the substitution of Co2+ in wurtzite ZnO lattice. The LVM at 723 cm−1 is found to be an elemental sensitive vibration mode for Co substitution. The LVM at 699 cm−1 can be attributed to enrichment of Co2+ bound with oxygen vacancy, the cobalt–oxygen vacancy–cobalt complexes, in Zn1−xCoxO films associated with ferromagnetism. The intensity of LVM at 699 cm−1, as well as saturated magnetization, enhanced after the vacuum annealing and depressed after oxygen annealing. 相似文献
17.
采用反应射频磁控溅射方法,在经过不同方法处理的蓝宝石基片上,在同一条件下沉积了ZnO薄膜.利用原子力显微镜、X射线衍射、反射式高能电子衍射等分析技术,对基片和薄膜的结构、表面形貌进行了系统表征.研究结果显示,不同退火条件下的蓝宝石基片表面结构之间没有本质的差异,均为α-Al2O3 (001)晶面,但基片表面形貌的变化较大.在不同方法处理的蓝宝石基片上生长的ZnO薄膜均具有高c轴取向的织构特征,但薄膜的表面形貌差异较大.基片经真空退火处
关键词:
ZnO薄膜
反应磁控溅射
基片处理
形貌分析 相似文献
18.
Ph. Komninou Th. Kehagias A. Delimitis G.P. Dimitrakopulos J. Kioseoglou E. Dimakis A. Georgakilas Th. Karakostas 《Superlattices and Microstructures》2004,36(4-6):509
The structural properties of InN thin films, grown by rf plasma-assisted molecular beam epitaxy on Ga-face GaN/Al2O3(0001) substrates, were investigated by means of conventional and high resolution electron microscopy. Our observations showed that a uniform InN film of total thickness up to 1 μm could be readily grown on GaN without any indication of columnar growth. A clear epitaxial orientation relationship of , was determined. The quality of the InN film was rather good, having threading dislocations as the dominant structural defect with a density in the range of 109–1010 cm−2. The crystal lattice parameters of wurtzite InN were estimated by electron diffraction analysis to be a=0.354 nm and c=0.569 nm, using Al2O3 as the reference crystal. Heteroepitaxial growth of InN on GaN was accomplished by the introduction of a network of three regularly spaced misfit dislocation arrays at the atomically flat interface plane. The experimentally measured distance of misfit dislocations was 2.72 nm. This is in good agreement with the theoretical value derived from the in-plane lattice mismatch of InN and GaN, which indicated that nearly full relaxation of the interfacial strain between the two crystal lattices was achieved. 相似文献
19.
S. Rout N. Popovici S. Dalui M.L. Paramês R.C. da Silva A.J. Silvestre O. Conde 《Current Applied Physics》2013,13(4):670-676
This paper reports on the structural and optical properties of Co-doped TiO2 thin films grown onto (0001)Al2O3 substrates by non-reactive pulsed laser deposition (PLD) using argon as buffer gas. It is shown that by keeping constant the substrate temperature at as low as 310 °C and varying only the background gas pressure between 7 Pa and 70 Pa, it is possible to grow either epitaxial rutile or pure anatase thin films, as well as films with a mixture of both polymorphs. The optical band gaps of the films are red shifted in comparison with the values usually reported for undoped TiO2, which is consistent with n-type doping of the TiO2 matrix. Such band gap red shift brings the absorption edge of the Co-doped TiO2 films into the visible region, which might favour their photocatalytic activity. Furthermore, the band gap red shift depends on the films’ phase composition, increasing with the increase of the Urbach energy for increasing rutile content. 相似文献
20.
利用卢瑟夫背散射/沟道技术和金属有机化学气相沉积方法, 对蓝宝石衬底上 在不同温度、压强下生长的Ga2+xO3-x薄膜进行结构和结晶品质的测量与分析; 并结合高分辨X射线衍射分析技术, 通过对其对称(402)面的θ–2θ及ω扫描, 确定了其结构类型及结晶品质. 实验表明: 在相同的生长温度(500 ℃)下, 结晶品质随压强的下降而变好, 生长压强为15 Torr (1 Torr=133.322 Pa)的样品其结晶品质最好, 沿轴入射之比χmin值为14.5%; 在相同的生长压强(15 Torr)下, 结晶品质受生长温度的影响不大, 所以, 生长温度不是改变结晶品质的主要因素; 此外, 在相同的生长条件下制备的样品, 分别经过700, 800和900 ℃退火后, 其结晶品质随退火温度的变化而变化. 退火温度为800 ℃的样品的结晶品质最好, χmin值为11.1%; 当退火温度达到900 ℃时, 样品部分分解; 经热处理的样品其X射线衍射谱中有一个强的Ga2O3 (402)面衍射峰, 其半峰全宽为0.5°, 表明该Ga2O3外延膜是(402)择优取向.
关键词:
氧化镓
卢瑟夫背散射
X射线衍射
结晶品质 相似文献