P-type ZnO thin films prepared by in situ oxidation of DC sputtered Zn3N2:Ga

The feasibility of a new fabrication route for N and Ga codoped p-type ZnO thin films on glass substrates, consisting of DC sputtering deposition of Zn3N2:Ga precursors followed by in situ oxidation in high purity oxygen, has been studied. The effects of oxidation temperature on the structural, optical and electrical properties of the samples were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), optical transmittance and Hall effect measurements. The results were compared to a control film without Ga. XRD analyses revealed that the Zn3N2 films entirely transformed into ZnO films after annealing Zn3N2 films in oxygen over 500 ℃ for 2 h. Hall effect measurements confirmed p-type conduction in N and Ga codoped ZnO films with a low resistivity of 19.8 Ω·cm, a high hole concentration of 4.6 × 1018 cm-3 and a Hall mobility of 0.7 cm2/(V·s). These results demonstrate a promising approach to fabricate low resistivity p-type ZnO with high hole concentration.     

氮化Si基ZnO/Ga_2O_3制备GaN薄膜

利用射频磁控溅射法在Si衬底上先溅射ZnO缓冲层,接着溅射Ga2O3薄膜,然后ZnO/Ga2O3膜在管式炉中常压下通氨气进行氮化,反应自组生成GaN薄膜。XRD测量结果表明,利用该方法制备的GaN薄膜是沿c轴方向择优生长的六角纤锌矿多晶结构的薄膜,利用SEM观测了其表面形貌,PL测量结果发现了位于351nm处的室温光致发光峰。     

柔性PEN衬底ZnO：Ga薄膜的性能研究

以PEN柔性薄膜作为衬底,采用直流对靶磁控溅射的方法,在室温下制备ZnO：Ga薄膜。研究了不同溅射功率和不同溅射压强下制备出的薄膜表现出不同的光学和电学特性。经过溅射压强和溅射功率的优化,获得薄膜厚约900nm、电阻率为7．72×10^-4Ω·cm和可见光平均透过率超过75％的PEN衬底ZnO：Ga薄膜。将其应用于PE...     

Low-temperature deposition of transparent conducting Mn-W co-doped ZnO thin films

Mn-W co-doped ZnO(ZMWO) thin films with low resistivity and high transparency were successfully prepared on glass substrate by direct current(DC) magnetron sputtering at low temperature.The sputtering power was varied from 65 to 150 W.The crystallinity and resistivity of ZMWO films greatly depend on sputtering power while the optical transmittance and optical band gap are not sensitive to sputtering power.All the deposited films are polycrystalline with a hexagonal structure and have a preferred orientat...     

Si基氨化ZnO／Ga2O3薄膜制备GaN纳米线

利用射频磁控溅射法在Si(111)衬底上溅射ZnO中间层和Ga2O3薄膜，然后在管式炉中常压下通氨气对ZnO/Ga2O3薄膜进行氨化，高温下ZnO层在氨气气氛中挥发，而Ga2O3薄膜和氨气反应合成出GaN纳米线．X射线衍射测量结果表明利用该方法制备的GaN纳米线具有沿c轴方向择优生长的六角纤锌矿结构．利用扫描电子显微镜、透射电子显微镜、傅里叶红外透射谱、能量弥散谱及选区电子衍射观测并分析了样品的形貌、成分和晶格结构．研究发现ZnO层的挥发有利于Ga2O3和NH3反应合成GaN纳米线．     

Zn沉积时间对低温硫化制备ZnS薄膜性能的影响

采用磁控溅射方法在不同时间下沉积了Zn薄膜,接着先后在200℃和400℃温度下的硫蒸气和氩气氛中进行了低温硫化退火,时间都为1 h,最后得到不同厚度的六方相ZnS薄膜。以XRD、SEM、EDS和紫外可见分光光度计对薄膜进行表征。研究表明:随着Zn沉积时间的增加,硫化制备的ZnS薄膜的晶粒尺寸、光透过率、带隙、S/Zn摩尔比都发生了明显变化,但变化趋势不同。并且,对其低温硫化生长ZnS薄膜的机理进行了讨论。此外,硫化前的抽真空处理可以明显改善ZnS薄膜的质量。所有低温硫化制备的ZnS薄膜在400~1100 nm范围光透过率约为70%,带隙值为3.49~3.57 eV。其中,3 min沉积的Zn在抽真空后低温硫化生长的ZnS薄膜质量最佳。     

Al-Zr共掺杂ZnO透明导电薄膜制备及光电性能研究

采用直流磁控溅射法,在室温水冷玻璃衬底上制备出Al-Zr共掺杂的ZnO透明导电薄膜。研究结果表明,Ar气压强对Al-Zr共掺杂ZnO透明导电薄膜的结构和电阻率有显著影响。X射线衍射(XRD)表明,Al-Zr共掺杂ZnO透明导电薄膜为六角纤锌矿结构的多晶薄膜,且具有C轴择优取向。扫描电镜(SEM)观察表明,Ar气压强对Al-Zr共掺杂ZnO透明导电薄膜的微观结构影响较大。薄膜的厚度随Ar气压强的增加而变薄,在Ar气压强为2.5Pa时,制备的Al-Zr共掺杂ZnO薄膜电阻率具有最小值1.01×10-3Ω.cm,在可见光区(500～800nm)平均透过率超过93%。     

直流反应磁控溅射Al,N共掺方法生长p型ZnO薄膜及其特性

报道了利用直流反应磁控溅射以Al,N共掺杂技术生长p型ZnO薄膜 .ZnO薄膜在不同衬底温度下沉积于α Al2 O3 (0 0 0 1)衬底上 ,N来自NH3 与O2 的生长气氛 ,Al来自ZnxAl1-x(x =0 9)靶材 .利用XRD ,AFM ,Hall,SIMS和透射光谱对其性能进行了研究 .结果表明 ,ZnO薄膜具有高度c轴择优取向 ,4 5 0℃、6 0 0℃分别实现了p型转变 ,电阻率为 1e2 ～ 1e3 Ω·cm ,载流子浓度为 1e15～ 1e16cm-3 ,迁移率为 0.5～ 1.32cm2 / (V·s) .薄膜中Al原子促进了N原子的掺入 .实验还表明 ,p ZnO薄膜在可见光区域具有很高的透射率 (约为 90 % ) ,室温下光学带宽为 3 2 8eV     

Si基ZnO/Ga2O3氨化反应制备GaN薄膜

利用射频磁控溅射法在Si(111)衬底上先溅射ZnO缓冲层，接着溅射Ga2O3薄膜，然后ZnO／Ga2O3膜在开管炉中850℃常压下通氨气进行氨化，反应自组装生成GaN薄膜。XRD测量结果表明利用该方法制备的GaN薄膜是沿c轴方向择优生长的六角纤锌矿多晶结构的薄膜，利用傅里叶红外吸收光谱仪测量了薄膜的红外吸收谱，利用SEM和TEM观测了薄膜形貌，PL测量结果发现了位于350nm和421nm处的室温光致发光峰。     

直流反应磁控溅射Zn_(1-x)Cd)_xO薄膜的研究

用直流反应磁控溅射法在n Si(111)和玻璃衬底上生长高度择优取向的Zn1-xCdxO合金晶体薄膜,最佳生长温度为45 0℃(x=0 2 ) .当x≤0 6时,Zn1-xCdxO薄膜具有纯ZnO的六角结构,x =0 8时,薄膜是由ZnO六角结构晶体和CdO立方结构晶体组成的混合物.透射光谱测试表明,通过改变合金薄膜中Cd的含量,可以调节Zn1-x CdxO薄膜的禁带宽度.     

Fabrication of p-Type ZnO Thin Films via DC Reactive Magnetron Sputtering by Using Na as the Dopant Source

The Na-doped p-type ZnO thin films were prepared by DC reactive magnetron sputtering. Two types of substrates were used for separate testing purposes: silicon wafers for crystallinity measurements and glass slides for electrical and optical transmittance measurements. The lowest room-temperature resistivity under the optimal condition was 59.9 Ω cm, with a Hall mobility of 0.406 cm² V⁻¹s⁻¹ and a carrier concentration of 2.57 × 10¹⁷ cm⁻³. The Na-doped ZnO thin films possessed a good crystallinity with c-axis orientation and a high transmittance (∼85%) in the visible region. The effects of the substrate temperature on the crystallinity and the electrical properties were discussed.     

不同温度硫化生长ZnS薄膜的性能

采用磁控溅射方法在玻璃衬底上室温下沉积了Zn薄膜,接着将薄膜在硫蒸气和氩气氛中于200℃预热1 h,然后升温至250~500℃退火1 h。以XRD、SEM、EDS和紫外可见分光光度计对薄膜进行表征,并结合热力学计算结果研究了Zn薄膜硫化生长机理。Zn转变为ZnS的过程包括硫化反应以及S原子和Zn原子的扩散。研究还表明:第一步的200℃预热可在Zn薄膜表面形成ZnS,随后第二步退火的硫化温度对硫化薄膜光透过率、S/Zn摩尔比和结晶性都有明显影响;在大于或等于300℃的硫化温度下制备的ZnS薄膜在400~1100 nm范围光透过率高达约80%,带隙为3.54~3.60 eV,晶体结构为六方。     

ZnO films deposited on GaAs substrates with a SiO2 thin buffer layer

Sputter deposition of ZnO films on GaAs substrates has been investigated. ZnO films were radio frequency (rf)-magnetron sputter deposited on GaAs substrates with or without SiO₂ thin buffer layers. Deposition parameters such as rf power, substrate-target distance, and gas composition/pressure were optimized to obtain highly c-axis oriented and highly resistive films. Deposited films were characterized by x-ray diffraction, scanning electron microscopy (SEM), capacitance, and resistivity measurements. Thermal stability of sputter-deposited ZnO films (0.5–2.0 μm thick) was tested with a post-deposition heat treatment at 430°C for 10 min, which is similar to a standard ohmic contact alloying condition for GaAs. The ZnO/SiO₂/GaAs films tolerated the heat treatment well while the ZnO/GaAs films disintegrated. The resistivity (10¹¹ Ω-cm) of the ZnO films on SiO₂-buffered GaAs substrates remained high during the heat treatment. The post-deposition anneal treatment also enhances c-axis orientation of the ZnO films dramatically and relieves intrinsic stress almost completely. These improvements are attributed to a reduction of grain boundaries and voids with the anneal treatment as supported by SEM and x-ray diffraction measurement results.     

Magnetic properties of ZnO:Cu thin films prepared by RF magnetron sputtering

ZnO films and ZnO:Cu diluted magnetic semiconductor films were prepared by radio frequency magnetron sputtering on Si (111) substrates, with targets of ZnO and Zn0.99Cu0.01 O, respectively. The plasma emission spectra were analyzed by using a grating monochromator during sputtering. The X-ray photoelectron spectroscopy measurements indicate the existence of Zni defect in the films, and the valence state of Cu is 1. The X-ray diffraction measurements indicate that the thin films have a hexagonal wurtzite structure and have a preferred orientation along the c-axis. The vibrating sample magnetometer measurements indicate that the sample is ferromagnetic at room temperature, and the origin of the magnetic behavior of the samples is discussed.     

射频磁控溅射法制备ZnO:Cu薄膜的磁性研究

ZnO films and ZnO：Cu diluted magnetic semiconductor films were prepared by radio frequency mag-netron sputtering on Si （111） substrates, with targets of ZnO and Zn0.99Cu0.01O, respectively. The plasma emission spectra were analyzed by using a grating monochromator during sputtering. The X-ray photoelectron spectroscopy measurements indicate the existence of Zni defect in the films, and the valence state of Cu is 1＋. The X-ray diffraction measurements indicate that the thin films have a hexagonal wurtzite structure and have a preferred orientation along the c-axis. The vibrating sample magnetometer measurements indicate that the sample is ferromagnetic at room temperature, and the origin of the magnetic behavior of the samples is discussed.     

氮气中退火对ZnO薄膜结构与光学性能的影响

采用直流磁控溅射法制备了ZnO薄膜,并将样品在氮气中进行了退火.对样品的表面形貌、结构性能、发光特性、透射光谱分别进行了检测.结果表明:退火后,样品的结晶质量提高,光致发光峰增强,在可见光范围内的平均透过率也有所增加.计算表明:退火后ZnO薄膜的禁带宽度略有减小.这可能是氮掺入ZnO薄膜后,N2p与O2p形成杂化轨道,二者能带部分重叠,从而使价带变宽、禁带变窄.     

磁控溅射法制备Ag掺杂p型ZnO薄膜的研究

采用磁控溅射法在石英玻璃基片上生长ZnO和ZnO:Ag薄膜。借助于SEM、XRD、霍尔测试、透射谱测试等方法,分析了O2气氛下退火温度对薄膜结构和电学性能的影响。霍尔测试结果表明,Ag掺杂ZnO薄膜经过600℃的O2气氛中热处理转变为p型电导。薄膜的XRD测试表明晶粒大小随退火温度升高而增大,所有薄膜样品只出现(002)衍射峰,呈现c轴取向生长。薄膜对可见光的透过率大于83%,其吸收限为378nm。     

Influence of N2 introduction on structural and optical properties of V-doped ZnO thin films grown by low-temperature reactive RF magnetron sputtering

The influences of N₂ introduction to a sputtering gas on structural and optical properties of vanadium-doped ZnO (VZO) films, grown by using reactive RF magnetron sputtering on a quartz substrate at room temperature, were investigated. In the VZO films, V doping caused to form a large number of O vacancies (V_O) and degraded both the c-axis orientation and optical transmittance. While, on the contrary, the ZnO(002) diffraction intensity of 3.5-at.% VZO films increased adding N₂ with a partial pressure ratio (α_N2) >2% reaching a maximum at α_N2 =5%. The average optical transmittance (wavelengths: 450−800 nm) of the 3.5-at.% VZO films was also improved by the N₂ introduction and reached 74% at α_N2 =5%. As a result of the analyses of the chemical binding states of the incorporated N atoms via the Raman spectroscopy and XPS, it was confirmed that the O sites were substituted by the N atoms and the amount of incorporated N increased by the high V doping. From the above, the N₂ introduction was effective to suppress the V_O formation even in room-temperature-grown VZO films, so it enables to improve both the c-axis orientation and optical transmittance.     

Effects of annealing temperature on the photoluminescence of RF sputtered Barium titanate thin films

BaTiO₃ thin films were deposited onto quartz substrates by an RF magnetron sputtering method. The films deposited at room temperature and annealed at 773–1173 K were characterized using X-ray diffraction (XRD)Scanning electron microscopy (SEM), UV–vis spectroscopy and Photoluminescence spectroscopy (PL). X-ray diffraction studies revealed that the film is amorphous in nature at 773 K and that the crystallinity increases with increase in annealing temperature. The average crystallite size of the films increased from 13–18 nm and the optical band gap decreased in the range of 4.33–3.43 eV, with increase in annealing temperature. The films exhibited good adherence to the substrates and the SEM images showed smooth surface morphology. Energy dispersive X-ray (EDX) analysis confirmed the presence of barium, titanium and oxygen in the film. The red-shifts of excitonic UV emission peaks were observed in all samples which can be attributed to the stress produced due to lattice distortions. The visible PL emission intensity showed appreciable enhancement with post-deposition annealing.