溅射功率对AZO／Cu／AZO多层薄膜结构与光电性能的影响

在玻璃衬底上利用磁控溅射法制备AZO／Cu／AZO多层薄膜,研究了溅射功率对AZO薄膜的微观结构和光电性能的影响。采用X射线衍射（XRD）仪、扫描电子显微镜（SEM）、紫外可见光谱仪（UVVis）等方法,对AZO薄膜的形貌结构、光电学性能进行了测试。结果表明：不同溅射功率下沉积的AZO薄膜均呈C轴择优取向,溅射功率对AZO／cu／AZO多层薄膜结构与光电性能有一定的影响。在溅射功率为120W、衬底温度为2500C、溅射气压为0．5Pa时薄膜的光透过率为75％,最低电阻率为2．2×10-4Ω·cm、结晶质量、表面形貌等得到明显改善。     

AZO薄膜制备工艺及其性能研究

综述了掺铝氧化锌(AZO)薄膜制备方法与光电特性,重点阐述了磁控溅射法制备工艺参数如衬底温度、溅射功率、气体压强、溅射时间、衬底和靶间距、负偏压等对AZO薄膜结构、光电性能的影响,并指出目前AZO薄膜的研究关键以及所面临的挑战,展望了未来的研究方向。     

氢化及沉积温度对掺铝ZnO透明导电薄膜性能影响

采用射频磁控溅射方法在玻璃衬底上制备了掺铝ZnO透明导电薄膜(AZO)。为了降低AZO薄膜的电阻率, 采用在溅射气氛中通入一定比例H₂的方法对AZO薄膜进行氢化处理, 并研究了溅射气氛中H₂含量及衬底温度对AZO薄膜氢化效果的影响。结果表明: 在低温条件下, 氢化处理能有效降低AZO薄膜的电阻率; 在衬底温度为100℃的低温条件下, 通过调节溅射气氛中H₂的比例, 制备了电阻率为6.0×10^-4 Ω·cm的高质量氢化AZO薄膜, 该电阻值低于同等条件下未氢化AZO薄膜电阻值的1/3; 但随着衬底温度的升高, 氢化处理对薄膜电学性能的改善效果逐渐减弱。     

直流磁控溅射技术低温制备高电导和高透明的氢掺杂AZO薄膜

采用直流磁控溅射的方法制备掺铝氧化锌(AZO)透明导电薄膜,通过溅射过程中加入氢气的方法来降低AZO薄膜的电阻率。结果表明:通过加入氢气的方法能有效降低AZO薄膜的电阻率;在衬底温度为225℃的低温条件下,通过优化其它沉积参数,制备了电阻率最低为4.5×10~(-4)Ω·cm、可见光区平均透光率在90%的优质AZO薄膜。这说明在溅射过程中引入一定流量的氢气,H可以起到掺杂作用,提高AZO薄膜的电导率。     

溅射功率对AZO透明导电薄膜的影响

采用射频磁控溅射法在玻璃衬底上沉积了AZO透明导电薄膜,并用原子力显微镜观测了薄膜表面形貌,XRD测试了薄膜相结构和单色仪测试了薄膜透射率。结果表明,制备的薄膜具有高度c轴择优取向性,其表面平整,晶粒均匀致密。当溅射功率为180W、溅射气体流量为15sccm、基片温度为200℃时制得的薄膜方阻为10Ω/□,在可见光区平均透射率大于85%。     

射频溅射工艺参数对AZO薄膜结构和性能的影响

采用射频磁控溅射法制备了掺铝氧化锌(AZO)薄膜,研究了衬底温度及溅射工作压强对沉积薄膜的晶体结构、表面形貌及电学性能的影响。结果显示,随衬底温度增加,薄膜的结晶结构发生显著变化,而溅射工作气压增加主要影响沉积薄膜(103)面与(002)面的相对强度。薄膜的表面形貌受温度影响严重,而气压对形貌的影响相对较小。衬底温度增加,薄膜的电阻率急剧降低,迁移率和载流子浓度都显著增加,而工作气压增加则导致电阻率先减小后增大。     

工艺参数对直流反应磁控溅射ZnO:Al薄膜沉积速率的影响

实验以合金靶材在玻璃衬底上运用直流反应磁控溅射法制备了ZAO(ZnO:Al)透明导电薄膜样品.研究了O2气流量,衬底温度,以及反应气压和溅射功率等工艺参数对ZAO薄膜沉积速率的影响规律.结果表明:沉积速率随O2气流量的增加显著降低,靶面溅射模式由金属模式转变为氧化物模式,而且这种转变趋势在改变其他参数时依然明显;沉积速率随溅射功率的增大几乎成线性增加,但随衬底温度的变化并不大;在反应气压增大的情况下,沉积速率不断上升,达到最大值后,又随气压的增大不断下降.     

脉冲磁控溅射沉积微晶硅薄膜工艺研究

采用脉冲磁控溅射法制备氢化微晶硅薄膜,利用X射线衍射、拉曼光谱、扫描电子显微镜和四探针测试仪对薄膜结构和电学性能进行表征和测试,研究了衬底温度、氢气稀释浓度和溅射功率对硅薄膜结构和性能的影响。结果表明:在一定范围内,通过控制合适的衬底温度、增大氢气稀释浓度及提高溅射功率,可以制备高质量的微晶硅薄膜。在衬底温度为400℃、氢气稀释浓度为90%及溅射功率为180W的条件下制备的微晶硅薄膜,其晶化率为72.2%,沉积速率为0.48nm/s。     

反应磁控溅射制备c轴择优取向氮化铝薄膜的研究进展

AlN薄膜在力学、光学和电子学中有着广泛的应用,而反应磁控溅射技术由于沉积温度低,成本低,非常适合沉积应用于GHz通信系统中体声波(BAW)和表面声波(SAW)器件的(002)取向的AlN薄膜.本文先概述了反应溅射的两个模型,然后综述了工艺参数包括溅射气压、溅射功率、氮气浓度、衬底温度、衬底种类、靶基距、薄膜厚度、衬底偏压、退火处理等对AlN薄膜生长和性能的影响.     

磁控溅射法制备CdS多晶薄膜工艺研究

采用磁控法制备了CdS薄膜,研究工艺参数对样品沉积质量、沉积速率及晶体结构的影响。实验发现,在不同衬底上制备CdS薄膜时需要采取不同的后续工艺措施以获得较好的沉积质量。同时,制备样品的沉积速率随衬底类型、衬底温度、溅射功率及溅射气压的变化而变化。讨论并给出了工艺参数对上述实验结果的影响机制。X射线衍射谱显示,制备样品是六方和立方两种晶型的混合,沿(002)和(111)晶面择优取向生长。随溅射功率的增大和衬底温度的升高,两种晶型互相竞争生长并分别略微占优势。当溅射功率增大到200 W,衬底温度升高到200℃时,占优势晶型消失,薄膜择优取向特性变得更好。此外,随着溅射气压的增大,样品结晶质量下降,在0.5 Pa时呈现明显非晶化现象。     

Deposition of Al-doped ZnO films on polyethylene naphthalate substrate with radio frequency magnetron sputtering

100 nm Al-doped ZnO (AZO) thin films were deposited on polyethylene naphthalate (PEN) substrates with radio frequency magnetron sputtering using 2 wt.% Al-doped ZnO target at various deposition conditions including sputtering power, target to substrate distance, working pressure and substrate temperature. When the sputtering power, target to substrate distance and working pressure were decreased, the resistivity was decreased due to the improvement of crystallinity with larger grain size. As the substrate temperature was increased from 25 to 120 °C, AZO films showed lower electrical resistivity and better optical transmittance due to the significant improvement of the crystallinity. 2 wt.% Al-doped ZnO films deposited on glass and PEN substrates at sputtering power of 25 W, target to substrate distance of 6.8 cm, working pressure of 0.4 Pa and substrate temperature of 120 °C showed the lowest resistivity (5.12 × 10^− 3 Ω cm on PEN substrate, 3.85 × 10^− 3 Ω cm on glass substrate) and high average transmittance (> 90% in both substrates). AZO films deposited on PEN substrate showed similar electrical and optical properties like AZO films deposited on glass substrates.     

Electrical mechanism analysis of Al2O3 doped zinc oxide thin films deposited by rotating cylindrical DC magnetron sputtering

Cost efficient and large area deposition of superior quality Al₂O₃ doped zinc oxide (AZO) films is instrumental in many of its applications, including solar cell fabrication due to its numerous advantages over indium tin oxide (ITO) films. In this study, AZO films were prepared by a highly efficient rotating cylindrical direct current (DC) magnetron sputtering system using an AZO target, which has a target material utilization above 80%, on glass substrates in argon (Ar) ambient. A detailed analysis on the electrical, optical, and structural characteristics of AZO thin films was performed for the solar cell, as well as display applications. The properties of films were found to critically depend on deposition parameters, such as sputtering power, substrate temperature, working pressure, and film thickness. A low resistivity of ~ 5.5 × 10^− 4 Ω cm was obtained for films deposited at 2 kW, keeping the pressure, substrate temperature and thickness constant at 3 mTorr, 230 °C and ~ 1000 nm respectively. This was due to an increase in carrier mobility and large grain size. Mobility is found to be controlled by ionized impurity scattering within the grains, since the mean free path of carriers is much smaller than the grain size of the films. The AZO films showed a high transparency of ~ 90% in the long wavelength region. Our results offer a cost-efficient AZO film deposition method that can fabricate films with significant low resistivity and high transmittance that can be applied in thin-film solar cells, as well as thin film transistor (TFT) and non-volatile memory (NVM).     

Highly conductive and transparent ZnO:Al thin films prepared on high-temperature substrates by d.c. magnetron sputtering

Highly conductive and transparent aluminium-doped ZnO (AZO) thin films have been prepared on high-temperature substrates using d.c. magnetron sputtering. In AZO films, the spatial distribution of resistivity across substrates placed parallel to the target was improved by deposition at substrate temperatures above 300 °C. AZO films with resistivities of 2−5 x 10⁻⁴ Ω cm were prepared under sputter gas pressures of between 0.6 and 3.0 Pa and at a substrate temperature of 350 °C. In addition, milky AZO films with a textured surface were prepared on high-temperature substrates under sputtering conditions which suppressed the c-axis orientation. A total transmittance of 72% and a haze factor of 63% at a wavelength of 500 nm and a sheet resistance as low as 2.0 Ω sq⁻¹ were obtained in milky AZO films 3 μm thick prepared at a sputter gas pressure of 12 Pa and a substrate temperature of 350 °C.     

Comparative study of resistivity characteristics between transparent conducting AZO and GZO thin films for use at high temperatures

This paper compares in detail the resistivity behavior of transparent conducting Al-doped and Ga-doped ZnO (AZO and GZO) thin films for use in an air environment at high temperatures. AZO and GZO thin films with thicknesses in the range from approximately 30 to 100 nm were prepared on glass substrates at a temperature of 200 °C by rf superimposed dc or conventional dc magnetron sputtering deposition, pulsed laser deposition or vacuum arc plasma evaporation techniques. In heat-resistance tests, the resistivity was measured both before and after heat tests for 30 min in air at a temperature up to 400 °C. The resistivity stability of AZO thin films was found to be always lower than that of GZO thin films prepared with the same thickness under the same deposition conditions, regardless of the deposition technique. However, the resistivity of all AZO and GZO thin films prepared with a thickness above approximately 100 nm was stable when heat tested at a temperature up to approximately 250 °C. It was found that the resistivity stability in both GZO and AZO thin films is dominated by different mechanisms determined by whether the thickness is below or above approximately 50 nm. With thicknesses above approximately 100 nm, the increase in resistivity found in GZO and AZO films after heat testing at a temperature up to 400 °C exhibited different characteristics that resulted from a variation in the behavior of Hall mobility.     

Effect of ZnO buffer layer on AZO film properties and photovoltaic applications

Aluminum-doped ZnO (AZO) transparent conducting films were deposited on glass substrates with and without intrinsic ZnO (i-ZnO) buffer layers by a home made and low cost radio-frequency (RF) magnetron sputtering system at room temperature in pure argon ambient and under a low vacuum level. The films were examined and characterized for electrical, optical, and structural properties for the application of CIGS solar cells. The influence of sputter power, deposition pressure, film thickness and residual pressure on electrical and optical properties of layered films of AZO, i-ZnO and AZO/i-ZnO was investigated. The optimization of coating process parameters (RF power, sputtering pressure, thickness) was carried out. The effects of i-ZnO buffer layer on AZO films were investigated. By inserting thin i-ZnO layers with a thickness not greater than 125 nm under the AZO layers, both the carrier concentration and Hall mobility were increased. The resistivity of these layered films was lower than that of single layered AZO films. The related mechanisms and plasma physics were discussed. Copper indium gallium selenide (CIGS) thin film solar cells were fabricated by incorporating bi-layer ZnO films on CdS/CIGS/Mo/glass substrates. Efficiencies of the order of 7–8% were achieved for the manufactured CIGS solar cells (4–5 cm² in size) without antireflective films. The results demonstrated that RF sputtered layered AZO/i-ZnO films are suitable for application in low cost CIGS solar cells as transparent conductive electrodes.     

Effect of Enhanced Plasma Density on the Properties of Aluminium Doped Zinc Oxide Thin Films Produced by DC Magnetron Sputtering

Aluminum doped zinc oxide (AZO) thin films were prepared by DC magnetron sputtering at low substrate temperature. A coaxial solenoid coil was placed near the magnetron target to enhance the plasma density (Ji). The enhanced plasma density improved significantly the bulk resistivity (ρ) and its homogeneity in spatial distribution of AZO films. X-ray diffraction (XRD) analysis revealed that the increased Ji had inuenced the crystallinity, stress relaxation and other material properties. The AZO films deposited in low plasma density (LPD) mode showed marked variation in ρ (ranging from ～6.5×10?2 to 1.9×10-3 ·cm), whereas those deposited in high plasma density (HPD) mode showed a better homogeneity of films resistivity (ranging from ～1.3×10?3 to 3.3×10?3 ?·cm) at di?erent substrate positions. The average visible transmittance in the wavelength range of 500-800 nm was over 80%, irrespective of the deposition conditions. The atomic force microscopy (AFM) surface morphology showed that AZO films deposited in HPD mode were smoother than that in LPD mode. The high plasma density produced by the coaxial solenoid coil improved the electrical property, surface morphology and the homogeneity in spatial distribution of AZO films deposited at low substrate temperature.     

室温下高速沉积AZO薄膜的研究

在室温下,采用射频磁控溅射技术以较大的功率密度(7W/cm2)沉积了一系列掺铝氧化锌(AZO)透明导电薄膜,探索了溅射压强对沉积速率及薄膜性能的影响。结果表明,当工作压强为2.0Pa时,高速(67nm/min)沉积得到的薄膜的电阻率为2.63×10-3Ω.cm,可见光平均透过率为83%,并且在薄膜表面有一定的织构。     

Effect of ZnO film deposition methods on the photovoltaic properties of ZnO–Cu2O heterojunction devices

The effect of ZnO film depositions using various film deposition methods such as magnetron sputtering (MSP), pulsed laser deposition (PLD) and vacuum arc plasma evaporation (VAPE) on the photovoltaic properties of ZnO–Cu₂O heterojunction solar cells is described in this report. In addition, the relationship between the resulting photovoltaic properties and the film deposition conditions such as supply power and substrate arrangement was investigated in Al-doped ZnO (AZO)–Cu₂O heterojunction devices fabricated using AZO thin films prepared by d.c. magnetron sputtering (d.c.MSP) or r.f. magnetron sputtering (r.f.MSP). The results showed that the measured photovoltaic properties of devices fabricated with films deposited on substrates oriented perpendicular to the target were better than those of devices fabricated with films deposited on substrates oriented parallel to the target. It was also found that ZnO film depositions under conditions where a relatively weaker oxidizing atmosphere was used yield better properties than films derived from MSP, which utilizes a high-density and high-energy plasma. Using VAPE and PLD, for example, high efficiencies of 1.52 and 1.42%, respectively, were obtained under AM2 solar illumination in devices fabricated at a substrate temperature around 200 °C.