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1.
闫大为  李丽莎  焦晋平  黄红娟  任舰  顾晓峰 《物理学报》2013,62(19):197203-197203
利用原子层沉积技术制备了具有圆形透明电 极的Ni/Au/Al2O3/n-GaN金属-氧化物-半导体结构, 研究了紫外光照对样品电容特性及深能级界面态的影响, 分析了非理想样品积累区电容随偏压增加而下降的物理起源. 在无光照情形下, 由于极长的电子发射时间与极慢的少数载流子热产生速率, 样品的室温电容-电压扫描曲线表现出典型的深耗尽行为, 且准费米能级之上占据深能级界面态的电子状态保持不变. 当器件受紫外光照射时, 半导体耗尽层内的光生空穴将复合准费米能级之上的深能级界面态电子, 同时还将与氧化层内部的深能级施主态反应. 非理想样品积累区电容的下降可归因于绝缘层漏电导的急剧增大, 其诱发机理可能是与氧化层内的缺陷态及界面质量有关的“charge-to-breakdown”过程. 关键词: 原子层沉积 2O3/n-GaN')" href="#">Al2O3/n-GaN 金属-氧化物-半导体结构 电容特性  相似文献   

2.
原子层沉积的SnOx薄膜具有良好的均匀性和致密性,常被用于提升倒置平面结构钙钛矿太阳能电池的稳定性。而SnOx薄膜的特性对器件能量转换效率(Power conversion efficiency,PCE)有着重要影响。本文通过氧源(H2O、O3)调控SnOx薄膜的能级和导电性,提升器件PCE。结果表明,O3作为单一氧源的SnOx薄膜(记为O3-SnOx)具有较优的能级排列;而只有H2O作氧源的SnOx薄膜(记为H2O-SnOx)具有较高的电导率。而采用O3和H2O混合氧源制备的SnOx(记为MIX-SnOx),则兼顾了能级匹配和良好的导电性,有效提升器件的PCE,达到20.9%。不仅如此,得益于SnOx  相似文献   

3.
基于固态分解原理,提出并验证了名为两步加热法(TSH)的CSD快速制备YBiO3缓冲层的技术方案。研究发现,聚丙烯酸-硝酸盐溶液前驱膜中的溶剂聚丙烯酸可以在40min内完全挥发。得到的无水硝酸盐混合物可以直接在高温下分解,并于1h内在钇稳定氧化锆上外延生长出YBiO3缓冲层,总工艺时间不足2h。测试结果表明,由此制得的YBiO3薄膜表面同样平整、致密,且具有良好的立方织构。两步加热法为涂层导体缓冲层的低成本连续制备提供了新的思路。  相似文献   

4.
本文通过倾斜衬底沉积技术在Hastelloy基底上成功生长出具有双轴织构的MgO缓冲层。系统研究了衬底倾角分别为30°和55°,薄膜厚度对MgO双轴织构、织构角以及表面形貌的影响。ISD-MgO薄膜最小面内、外半高宽分别为11.0°和6.6°。另外,800℃下,在ISD-MgO上自外延300 nm厚的MgO薄膜可以优化其表面质量,为涂层导体的制备提供高质量缓冲层。  相似文献   

5.
在采用高压高功率的甚高频等离子体增强化学气相沉积(VHF-PECVD)技术高速沉积微晶硅(μc-Si:H)太阳电池过程中,产生的高能离子对薄膜表面的轰击作用会降低薄膜质量和破坏p型掺杂层(p层)与本征层(i层)之间的界面特性.针对该问题提出在电池中引入低速沉积的p/i界面层的方法,即在p层上先低速沉积一薄层本征μc-Si:H薄膜,然后再高速沉积本征μc-Si:H薄膜.实验结果表明,引入低速方法沉积的界面层有效地提高了p/i界面特性和i层微结构的纵向均匀性,而随界面层厚度的增加,i层中的缺陷态先降低后增加, 关键词: μc-Si:H太阳电池 甚高频等离子体增强化学气相沉积 p/i界面层  相似文献   

6.
采用原子层沉积技术在熔石英和BK7玻璃基片上镀制了TiO2/Al2O3薄膜,沉积温度分别为110℃和280℃。利用X射线粉末衍射仪对膜层微观结构进行了分析研究,并在激光损伤平台上进行了抗激光损伤阈值测量。采用Nomarski微分干涉差显微镜和原子力显微镜对激光损伤后的形貌进行了观察分析。结果表明,采用原子层沉积技术镀制的TiO2/Al2O3增透膜的厚度均匀性较好,Φ50 mm样品的膜层厚度均匀性优于99%;光谱增透效果显著,在1 064 nm处的透过率〉99.8%;在熔石英和BK7基片上,TiO2/Al2O3薄膜在110℃时的激光损伤阈值分别为(6.73±0.47)J/cm2和(6.5±0.46)J/cm2,明显高于在280℃时的损伤阈值。  相似文献   

7.
等离子增强原子层沉积低温生长AlN薄膜   总被引:2,自引:0,他引:2       下载免费PDF全文
冯嘉恒  唐立丹  刘邦武  夏洋  王冰 《物理学报》2013,62(11):117302-117302
采用等离子增强原子层沉积技术在单晶硅基体上成功制备了AlN晶态薄膜, 利用椭圆偏振仪、原子力显微镜、小角掠射X射线衍射仪、高分辨透射电子显微镜、 X射线光电子能谱仪对样品的生长速率、表面形貌、晶体结构、薄膜成分进行了表征和分析, 结果表明, 采用等离子增强原子层沉积制备AlN晶态薄膜的最低温度为200 ℃, 薄膜表面平整光滑, 具有六方纤锌矿结构与(100)择优取向, Al2p与N1S的特征峰分别为74.1 eV与397.0 eV, 薄膜中Al元素与N元素以Al-N键相结合, 且成分均匀性良好. 关键词: 氮化铝 等离子增强原子层沉积 低温生长 晶态薄膜  相似文献   

8.
以乙酰丙酮铱[Ir(acac)3]和高纯氧为前驱体,采用原子层沉积(ALD)方法在基板温度为340℃的石英玻璃和硅基板上制备了金属铱薄膜。采用反射光谱测试仪、X射线电子能谱(XPS)、X射线衍射(XRD)、扫描电子显微镜(SEM)和原子力显微镜(AFM)等手段对不同厚度薄膜的微结构、表面形貌和光学性能进行了研究。结果表明,原子层沉积制备的Ir薄膜中元素纯度较高(大于95%),表面粗糙度低,并呈现多晶纳米颗粒。同时,Ir薄膜在紫外波段表现出较好的光学特性,可以用于制作Ir金属紫外光栅等光学器件。  相似文献   

9.
等离子增强原子层沉积低温生长GaN薄膜   总被引:2,自引:0,他引:2       下载免费PDF全文
汤文辉  刘邦武  张柏诚  李敏  夏洋 《物理学报》2017,66(9):98101-098101
采用等离子增强原子层沉积技术在低温下于单晶硅衬底上成功生长了Ga N多晶薄膜,利用椭圆偏振仪、低角度掠入射X射线衍射仪、X射线光电子能谱仪对薄膜样品的生长速率、晶体结构及薄膜成分进行了表征和分析.结果表明,等离子增强原子层沉积技术生长Ga N的温度窗口为210—270?C,薄膜在较高生长温度下呈多晶态,在较低温度下呈非晶态;薄膜中N元素与大部分Ga元素结合成N—Ga键生成Ga N,有少量的Ga元素以Ga—O键存在,多晶Ga N薄膜含有少量非晶态Ga_2O_3.  相似文献   

10.
反应溅射沉积技术(RSDT)可以生成纳米大小的颗粒并有效溅射形成性能稳定的催化层,是一项崭新的催化层制备技术。为从理论上研究RSDT过程的复杂物理化学过程,本文提出了RSDT过程的三维综合数学模型,模型描述了流体流动、热/质传递,并与燃料气的化学反应和液滴的燃烧相耦合。RNGκ-ε模型用于描述湍动燃烧气流,液滴的跟踪和分析在拉格朗日框架下进行,并利用Monte Carlo方法生成了催化层的表面结构。计算结果可以为该技术的优化提供一定的参考。  相似文献   

11.
樊继斌  刘红侠  马飞  卓青青  郝跃 《中国物理 B》2013,22(2):27702-027702
A comparative study of two kinds of oxidants(H2O and O3) with the combinations of two metal precursors [trimethylaluminum(TMA) and tetrakis(ethylmethylamino) hafnium(TEMAH)] for atomic layer deposition(ALD) hafnium aluminum oxide(HfAlOx) films is carried out.The effects of different oxidants on the physical properties and electrical characteristics of HfAlOx films are studied.The preliminary testing results indicate that the impurity level of HfAlOx films grown with both H2O and O3 used as oxidants can be well controlled,which has significant effects on the dielectric constant,valence band,electrical properties,and stability of HfAlOx film.Additional thermal annealing effects on the properties of HfAlOx films grown with different oxidants are also investigated.  相似文献   

12.
This paper studies systematically the drain current collapse in AlGaN/GaN metal-oxide-semiconductor high electron mobility transistors (MOS-HEMTs) by applying pulsed stress to the device. Low-temperature layer of Al2O3 ultrathin film used as both gate dielectric and surface passivation layer was deposited by atomic layer deposition (ALD). For HEMT, gate turn-on pulses induced large current collapse. However, for MOS-HEMT, no significant current collapse was found in the gate turn-on pulsing mode with different pulse widths, indicating the good passivation effect of ALD Al2O3. A small increase in Id in the drain pulsing mode is due to the relieving of self-heating effect. The comparison of synchronously dynamic pulsed Id - Vds characteristics of HEMT and MOS-HEMT further demonstrated the good passivation effect of ALD Al2O3.  相似文献   

13.
In this paper the fabrication and characterization of IV-VI semiconductor Pb1−xSnxSe (x = 0.2) thin films on gold substrate by electrochemical atomic layer deposition (EC-ALD) method at room temperature are reported. Cyclic voltammetry (CV) is used to determine approximate deposition potentials for each element. The amperometric I-t technique is used to fabricate the semiconductor alloy. The elements are deposited in the following sequence: (Se/Pb/Se/Pb/Se/Pb/Se/Pb/Se/Sn …), each period is formed using four ALD cycles of PbSe followed by one cycle of SnSe. Then the deposition manner above is cyclic repeated till a satisfactory film with expected thickness of Pb1−xSnxSe is obtained. The morphology of the deposit is observed by field emission scanning electron microscopy (FE-SEM). X-ray diffraction (XRD) pattern is used to study its crystalline structure; X-ray photoelectron spectroscopy (XPS) of the deposit indicates an approximate ratio 1.0:0.8:0.2 of Se, Pb and Sn, as the expected stoichiometry for the deposit. Open-circuit potential (OCP) studies indicate a good p-type property, and the good optical activity makes it suitable for fabricating a photoelectric switch.  相似文献   

14.
利用固相反应烧结技术制备La0.1Bi0.9-xEuxFeO3系列化合物. 利用X射线粉末衍射进行物相鉴定和结构分析,确定了材料的相关系:x≤0.05,材料为R3c结构相;0.08≤x≤0.12,材料为赝R3c结构相;x≥0.15是Pbnm相,其中0.15≤x≤0.20区域Pbnm相存在畸变. 磁测量结果表明,材料具有弱铁磁性,对于x≤0.20材料,磁矩在x=0.12成分存在极值. 利用阻抗分析仪测量了室温介电常数随成分的变化关系.讨论了材料的结构与弱铁磁性和室温介电常数间的关系. 关键词: 0.1Bi0.9-xEuxFeO3')" href="#">La0.1Bi0.9-xEuxFeO3 X射线衍射 磁性 介电常数  相似文献   

15.
La2O3 grown by atomic layer deposition (ALD) and thermally grown GeO2 are used to establish effective electrical surface passivations on n-type (1 0 0)-Ge substrates for high-k ZrO2 dielectrics, grown by ALD at 250 °C substrate temperature. The electrical characterization of MOS capacitors indicates an impact of the Ge-surface passivation on the interfacial trap density and the frequency dependent capacitance in the inversion regime. Lower interface trap densities can be obtained for GeO2 based passivation even though a chemical decomposition of the oxidation states occur during the ALD of ZrO2. As a consequence the formation of a ZrGeOx compound inside the ZrO2 matrix and a decline of the interfacial GeO2 are observed. The La2O3 passivation provides a stable amorphous lanthanum germanate phase at the Ge interface but also traces of Zr germanate are indicated by X-ray-Photoelectron-Spectroscopy and Transmission-Electron-Microscopy.  相似文献   

16.
负载型金纳米颗粒催化剂在许多催化反应中展现出非常好的催化活性,但是金纳米颗粒在高温等反应条件下容易烧结团聚,极大地限制了金催化剂的应用。利用原子层沉积技术在Au/TiO2催化剂表面分别精确沉积了一层超薄的二氧化钛和氧化铝包裹层,并对比研究了包裹层对金纳米颗粒的热稳定性影响。原位红外漫反射CO吸附和x-射线光电子能谱数据证实了氧化物包裹层的存在。发现亚纳米厚的氧化铝包裹层能够在600 C完全避免金纳米颗粒的团聚;相反,二氧化钛包裹层对金纳米颗粒稳定性的提高没有明显效果。通过CO氧化探针反应的活性测试,发现随着煅烧温度的升高氧化铝包裹的Au/TiO2 催化剂的活性逐渐提高,表明高温处理可以促进被包裹金原子的暴露并表现出催化活性。提供了提高金纳米颗粒稳定性的有效方法,为拓展金催化剂在条件苛刻的反应中的应用奠定了技术基础.  相似文献   

17.
In this work, we report a study on the influence of CHx thickness layer on optical properties of CHx/PS/Si structures. The hydrocarbon groups were deposited by plasma of methane–argon mixture.The properties of these structures are investigated by photoluminescence (PL), reflection and spectral response measurements from where a different behavior depending on CHx layer thickness has been observed.The entire total reflection spectrum is modulated by Fabry–Pérot fringes that are a result of thin film interference. As the CHx layer thickness increases, the amplitude of the interferences decreases and a positive shift of the maximum peak is observed.The PL spectra from CHx/PS samples with two CHx layer thicknesses show more intense luminescence than that observed from PS sample and the existence of an optimum thickness CHx that gives the maximum PL intensity. The spectral response spectra show the presence of an intense peak at 450 nm. Finally, the results point out the importance of CHx coating in optoelectronic applications.  相似文献   

18.
Double-ceramic-layer (DCL) thermal barrier coatings (TBCs) of La2(Zr0.7Ce0.3)2O7 (LZ7C3) and La2Ce2O7 (LC) were deposited by electron beam-physical vapor deposition (EB-PVD). The composition, interdiffusion, surface and cross-sectional morphologies, cyclic oxidation behavior of DCL coating were studied. Energy dispersive spectroscopy and X-ray diffraction analyses indicate that both LZ7C3 and LC coatings are effectively fabricated by a single LZ7C3 ingot with properly controlling the deposition energy. The chemical compatibility of LC coating and thermally grown oxide (TGO) layer is unstable. LaAlO3 is formed due to the chemical reaction between LC and Al2O3 which is the main composition of TGO layer. Additionally, the thermal cycling behavior of DCL coating is influenced by the interdiffusion of Zr and Ce between LZ7C3 and LC coatings. The failure of DCL coating is a result of the sintering of LZ7C3 coating surface, the chemical incompatibility of LC coating and TGO layer and the abnormal oxidation of bond coat. Since no single material that has been studied so far satisfies all the requirements for high temperature applications, DCL coating is an important development direction of TBCs.  相似文献   

19.
ABSTRACT

Bi1 ? xLaxFeO3 single-phase solid solution with 0 ≤ x ≤ 0.3 was obtained by mechanochemical synthesis and characterized by X-ray diffraction, FT NIR Raman spectroscopy and magnetic studies. The nanocrystalline powders of rhombohedrally distorted perovskite structure R3c were studied ‘as synthesized’ by mechanosynthesis and after annealing at 500 °C for 1 h. The annealing, which resulted in recrystallization of the amorphous shell of the nanograins, was found to modify the external lattice modes of Bi1?xLaxFeO3 and resulted in changes in the temperature variation of the magnetization.  相似文献   

20.
We deposit Fe50PdxPt50−x alloy thin films by magnetron sputtering onto a TiN seed layer. Chemically ordered L10 films are obtained which display large perpendicular magnetic anisotropy. We find that the surface roughness of the film depends strongly on the growth and anneal conditions as well as the Pd composition of the film. Smooth films are obtained by deposition above the chemical ordering temperature and by removing Pd from the alloy.  相似文献   

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