Pulse-plating electrodeposition and annealing treatment of CuInSe2 films

CuInSe2 (CIS) thin film was prepared on molybdenum substrate using pulse-plating electrodeposition in aqueous solution. The most suitable pulse potential range for co-deposition is found to be from -0.55 to -0.75 V (vs SCE) from linear potential scanning curve. The electrodeposited films were characterized by X-ray diffractometry (XRD), scanning electron microscopy(SEM) and energy dispersive X-ray analysis (EDS). The annealing effects on electrodeposited precursors were investigated. And the influence of pulse parameters on film quality was studied. The chalcopyrite phase CuInSe2 films with smooth surface and stoichiometric composition are obtained at a pulse potential from -0.65 to -0.7 V (vs SCE), a pulse period of 1-9 ms with a duty cycle of 33% and annealing treatment.     

Preparation of CuInSe<Subscript>2</Subscript> films by ultrasonic electrodeposition-selenization and the improvement of their surface morphology

The CuInSe₂ compound was prepared by selenization of Cu-In precursor, which was ultrasonic electrodeposited at constant current. CuInSe₂ films were compacted to improve surface morphology. The films were characterized by X-ray diffractometry (XRD), scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS). It is indicated that ideal stoichiometric CuInSe₂ films can be obtained by the selenization of Cu-In precursor deposited at a current density of 20 mA/cm². Single-phase CuInSe₂ is formed in the selenization process, and it exhibits preferred orientation along the (112) plane. The CuInSe₂ films with smooth surface can be obtained under the pressure of 500 MPa at 60°C.     

电沉积法制备CuInSe2薄膜的组成与形貌

采电沉积法制备了CuInSe2薄膜材料，研究了制备工艺条件对材料组成、结构与性能的影响。研究结果表明：最佳的沉积电位范围为-0．6～0．8V（vsSCE）；硒化退火是获得高质量CuInSe，薄膜的必要过程，硒化退火温度应控制在440～610℃范围内；在不同沉积电位和不同电解质浓度组成溶液中，通过电沉积并在500℃下硒化退火均可获得黄铜矿结构CuInSe2多晶薄膜；沉积电位的负移会使膜层中CuInSe2的相对含量增加，晶型完善，且杂相减少；随着电解质浓度的增加，电沉积CuInSe2退火后结晶程度变好，颗粒变得粗壮，致密性也有所改善；电沉积并硒化退火后薄膜中的铜铟摩尔比受沉积电位和电解质浓度影响较大，当沉积电位为-0．7和-0．8V时，铜铟摩尔比约为1较为理想，且铜铟摩尔比的变化与电解液中CuCl2和InCl3的摩尔比变化一致。     

Preparation of CulnSe2 thin films by paste coating

Precursor pastes were obtained by milling Cu-In alloys and Se powders.CuInSe2 thin films were successfully prepared by precursor layers,which were coated using these pastes,and were annealed in a H2 atmosphere.The pastes were tested by laser particle diameter analyzer,simultaneous thermogravimetric and differential thermal analysis instruments (TG-DTA),and X-ray diffractometry (XRD).Selenized films were characterized by XRD,scanning electron microscopy (SEM),and energy dispersive spectroscopy (EDS).The results indicate that chalcopyrite CuInSe2 is formed at 180℃ and the crystallinity of this phase is improved as the temperature rises.All the CuInSe2 thin films,which were annealed at various temperatures,exhibit the preferred orientation along the (112) plane.The compression of precursor layers before selenization step is one oftbe most essential factors for the preparation of perfect CulnSe2 thin films.     

Laser annealing of flash-evaporated CuInSe2 thin films

In this paper, the impact of laser annealing on the structural, electrical, and optical properties of CuInSe₂ (CIS) thin films has been investigated. The films were deposited using a modified flash evaporation system onto glass substrates. Structural analysis using x-ray diffraction (XRD) showed that the films have a strong preferred growth direction in the 〈112〉 plane. After laser annealing with a diffused beam of 20 ns width, the structure was relaxed and an increase in the intensity of 〈112〉 diffraction line was observed. A gas-microphone-type, high-resolution, near-infared (IR) photoacoustic spectrometer was used for the analysis of nonradiative defect states in as-grown and laser-annealed CIS thin film samples at room temperature. The absorption coefficient has been derived from photoacoustic spectra to establish activation energies for several defect-related energy levels. The calculated intrinsic defect ionization energies were also compared with the existing data available in the literature. The changes in the optical properties of the films have been explained in terms of the variations in the structural characteristics within the material. This paper was presented at the fourth International Surface Engineering Congress and Exposition held August 1–3, 2005 in St. Paul, MN.     

退火处理对ITO和ITO:Zr薄膜性能的影响

利用磁控溅射在室温条件下沉积ITO薄膜和ITO：Zr薄膜,对比研究在空气中退火处理对ITO和ITO：Zr薄膜性能的影响。结果表明,Zr的掺杂促进了（400）晶面的取向,随着退火温度的升高,薄膜表面颗粒增大,表面粗糙度有所降低。室温下Zr的掺杂显著改善了薄膜的光电性能,随着退火温度的升高,ITO和ITO：Zr薄膜的方阻都表现为先降后升的趋势,ITO：Zr薄膜在较低的退火温度下可见光透过率就可达到80%以上,直接跃迁模型确定的光学禁带宽度Eg呈现了先升后降的变化。ITO：Zr薄膜比ITO薄膜显示了更高的效益指数,揭示了ITO：Zr薄膜具有更好的光电性能。     

Al掺杂ZnO薄膜的热处理工艺与性能研究

采用陶瓷烧结靶材、射频磁控溅射法制备了(002)择优取向的Al掺杂ZnO薄膜,着重研究了不同的热处理工艺对显微结构、光电性能的影响。结果表明,真空400℃退火能大幅提高ZAO薄膜的导电性能,并保持其平均透光率在85%以上,而非真空退火(大气环境)将使ZAO薄膜材料绝缘化,400℃真空退火时间或退火次数对导电性能无明显影响,但随退火时间和退火次数的增加薄膜组织恶化,在真空循环退火条件下尤为严重;经400℃真空退火的薄膜样品,其最低电阻率达8.4×10-4Ω.cm。     

磁控溅射和退火制备ZnO/SiO2复合薄膜

采用射频磁控溅射和退火处理的方法在单晶硅衬底上制备了ZnO/SiO2复合薄膜,利用X射线衍射(XRD)、扫描电镜(SEM)、能谱分析(EDS)和接触角测量等测试手段研究溅射气压、溅射功率、氧氩比和退火温度等对复合薄膜成分组成、组织结构及润湿性能的影响。研究表明,复合薄膜中主要有ZnO、SiO2、Zn2SiO4 3种物相,且分别以六方纤锌矿结构、无定形态和硅锌矿型等形式存在。随着溅射和退火工艺的改变,复合薄膜的接触角在41°～146°间变化,组织形态由颗粒状向纳米竹叶状变化。溅射气压0.5 Pa,溅射功率120 W,氧氩比(O2∶Ar)为0∶30,退火温度为700℃的条件下获得具有六方纤锌矿结构的ZnO纳米组织,该组织呈现出竹叶状,在薄膜表面交错排列形成了无序多空隙的微观形貌,使复合薄膜具有超疏水性,接触角为146°。     

Effect of annealing temperature on structure and electrochemical properties of LiCoO2 cathode thin films

LiCoO2 thin films, which can be used as a cathode material in microbatteries, were deposited using radio frequency (r.f.) magnetron sputtering system from a LiCoO2 target and in an O2+Ar atmosphere.The films were characterized by various methods such as XRD, SEM and AFM.The LiCoO2 films were annealed in air at 300, 500, 700 and 800 ℃ respectively.The effect of the annealing temperature on the structure, the surface morphology and the electrochemical properties of the films were investigated.The LiCoO2 thin film deposited at room temperature is amorphous and has smaller grain size.With increasing of annealing temperature, the crystallinity of the films is promoted.When the annealing temperature increases to 700 ℃, the films have a perfect crystalline LiCoO2 phase.The LiCoO2 thin film without annealing has no discharge plateau and small discharge capacity (about 27 μAh·cm-2μm).The discharge capacity increases with the increasing of annealing temperature and reaches 47 μAh·cm-2μm for the film annealed with 700 ℃, which also shows the typical discharge plateau of 3.9 V.The cycle performance of LiCoO2 thin films of as grown and annealed at different temperatures were studied.In the case of the film without thermal treatment, the capacity fading is much faster than that of the film annealed at different temperature, showing about 40% capacity loss only after 25 cycles.However, in the case of the film annealed at 700 ℃, the capacity reaches to steady state gradually and maintained constantly with cycling.After 25 times cycling, the discharge capacity of the film annealed at 700 ℃ decreases to about 36.9 μAh·cm-2·μm, only 0.8% capacity loss per cycle.     

Effect of sputtering pressure and rapid thermal annealing on optical properties of Ta2O5 thin films

Ta2O5 thin films were deposited by DC reactive magnetron sputtering followed by rapid thermal annealing(RTA). Influence of sputtering pressure and annealing temperature on surface characteristics, microstructure and optical property of Ta2O5 thin films were investigated. As-deposited Ta2O5 thin films are amorphous. It takes hexagonal structure (δ-Ta2O5) after being annealed at 800 ℃. A transition from δ-Ta2O5 to orthorhombic structure (L-Ta2O5) occurs at 900-1 000 ℃. Surface roughness is decreased after annealing at low temperature. Refractive index and extinction coefficient are decreased when annealing temperature is increased.     

磁控溅射TiO2薄膜的相结构转变温度

利用射频磁控溅射制备了TiO2致密薄膜,并通过退火处理实现TiO2的相转变,采用扫描电镜,X射线衍射等手段对薄膜相结构进行表征并做了详细的分析,结果表明,退火后TiO2薄膜结构致密,表面呈现出大小均匀的纳米晶粒。400 ℃退火时,TiO2薄膜为单一的锐钛矿相,500～600 ℃退火时为锐钛矿和金红石混合相,700 ℃以上退火时则完全转变为金红石相。     

Bi-Ni合金膜在有机溶剂中的电沉积制备

利用循环伏安法和恒电位电解法探讨了室温条件下LiClO4-二甲基亚砜(DMSO)体系中Bi-Ni合金膜的电化学制备；利用SEM，EDS和XRD分析了沉积膜的微观表面形貌，组成和相结构；研究了沉积电位、电流密度、主盐浓度以及NiCl2与Bi(NO3)3的浓度比对沉积膜质量的影响。实验结果表明：在Bi(NO3)3一NiCl2-LiClO4-DMSO体系中，控制恰当的体系组成和沉积条件，可得到表面均匀、附着力强、有金属光泽的灰色非晶态Bi-Ni合金膜，其中Ni的质量分数可达1．82％～38．08％，合金膜在268℃热处理1h后，可形成晶态的Bi-Ni合金相。     

Effect of annealing treatment onoptical and electrical properties of ZnO films

The ZnO-Al films were prepared by R. F. magnetron sputtering system using a Zn-Al target (with purity of 99.99 %). The obtained films were characterized by X-ray diffraction, SEM and optical and electrical measurements. The experimental results show that the properties of ZnO films can be further improved by annealing treatment. The crystallinity of ZnO films becomes better, and the optical gap energy is decreased, but thermoelectric power is enhanced after heat treatment. The optical gap energy decreases from 3.75 eV to 3.68 eV when the annealing temperature increases from 25℃ to 400℃. This can be ascribed to the decrease of carrier concentration, resulting in Burstein shift.     

Effect of annealing treatment on the structural, optical, and electrical properties of Al-doped ZnO thin films

Highly conductive and transparent Al-doped ZnO (AZO) thin films were prepared from a zinc target containing Al (1.5 wt.%) by direct current (DC) and radio frequency (RF) reactive magnetron sputtering. The structural, optical, and electrical properties of AZO films as-deposited and submitted to annealing treatment (at 300 and 400 ℃, respectively) were characterized using various techniques. The experimental results show that the properties of AZO thin films can be further improved by annealing treatment. The crystallinity of ZnO films improves after annealing treatment. The transmittances of the AZO thin films prepared by DC and RF reactive magnetron sputtering are up to 80% and 85% in the visible region, respectively. The electrical resistivity of AZO thin films prepared by DC reactive magnetron sputtering can be as low as tering have better structural and optical properties than that prepared by DC reactive magnetron sputtering.     

Influence of post-grown treatments on CuInS2 thin films prepared by sulphurization of Cu-In films

Polycrystalline CuInS2 (CIS) films were prepared by sulphurization of Cu-In films.The surface morphology and phase composition of the as-grown film,the KCN-etched film,and the annealed KCN-etched film were investigated.During the sulphurization,the secondary CuχS phase segregated on the surface of the as-grown films.To improve the crystalline quality of CulnS2 films,a series of post-grown treatments,such as KCN-etching and vacuum annealing KCN-etched films,were performed on the as-grown films.Both as-grown and post-treated films were characterized by X-ray diffraction (XRD),scanning electron microscopy (SEM),and energy dispersive spectroscopy (EDS).The results indicated that a CuχS secondary phase segregated on the surface of the as-grown film,which could be removed effectively by KCN etching.After the vacuum annealing treatment,the KCN-etched film had a sphalerite structure with (112) preferred orientation.Meanwhile,the crstalline quality of the CIS film was significantly improved,which provided a novel method to improve the performance of thin film solar cells.     

Effects of substrate temperature and annealing treatment on the microstructure and magnetic characteristics of TbDyFe films

A series of TbDyFe films were prepared by DC magnetron sputtering. The effects of substrate temperature and annealing temperature on the phase structure and the magnetic properties of the sample films were investigated. The an-nealing treatment has a significant influence on the microstructure and the magnetic properties of the sample. The results obtained by XRD indicate that the films deposited at a temperature lower than 525℃ are amorphous and have an easy magnetization direction perpendicular to the film plane. An RFe2 phase is formed in the sample annealed at 550℃ and the residual phases observed are Fe and rare earth oxide. The magnetic properties Hc and Mr/Ms of the film annealed at 550℃ obtain the maximum values,for which the formation of the RFe2 phase is mainly responsible. An annealing treatment leads to a rotation of the sample’s easy axis from being parallel to the film surface to becoming vertical.     

微波退火时间对HfO2薄膜结构和光电性能的影响

采用原子层沉积(ALD)方法在硅衬底上沉积了氧化铪(HfO₂)薄膜,对其进行不同时间的微波退火(MWA)。采用X射线衍射(XRD)、拉曼光谱(Raman)、原子力显微镜(AFM)、紫外可见光谱(UV-Vis)、椭偏仪(SE)和阻抗分析仪对薄膜的物相结构、形貌和光电性能进行表征,研究了微波退火时间对薄膜结构、光学和电学性能的影响。结果表明：沉积态的HfO₂薄膜具有非晶态性质;当微波退火时间从5 min增至20 min时,HfO₂薄膜的折射率几乎不变,结晶性增强,表面粗糙度降低,但介电常数却减小。     

Transmission photoacoustic spectroscopy analysis of CuIn0.75Ga0.25Se2 thin films

Photoacoustic spectroscopy (PAS) has proved to be an effective technique for the evaluation of the inherent defect population in a wide range of materials for various applications. This paper demonstrates the use of this technique in transmission mode, and hence, evaluates the optical properties of flash-evaporated CuIn_0.75Ga_0.25Se₂ (CIGS) thin films. Both the photoacoustic and transmission spectra were recorded at room temperature using high-resolution near-IR of the gas-microphone-type PAS, which revealed a very broad transmission region (about 300 meV) near the fundamental band edge in the as-grown CIGS thin films due to the presence of several shallow defect levels. The postdeposition heat treatment of the samples under Se ambient, followed by annealing under inert and forming gas ambient, showed significant changes in the behavior of the PAS spectra, particularly near the fundamental band edge. The absorption coefficient has been derived from these spectra to determine the energy band gap values and the activation energies for several defect related energy levels. Using PAS, the energy band gap values were in the range of 1.197 to 1.202 eV. The optical transmission spectra were also recorded from the routinely used spectrophotometer. The transmission data was used to determine the energy band-gap values, which were calculated to be in the range from 1.159 to 1.194 eV. These values were found to be in good agreement with each other, as well as with values reported in the literature. This paper was presented at the fourth International Surface Engineering Congress and Exposition held August 1–3, 2005 in St. Paul, MN.     

Evolution of structural, surfacial and mechanical properties of titanium-nickel-copper thin films during rapid thermal annealing

The structural, surfacial and nanoscale mechanical properties evolution of Ti-Ni-Cu thin films, prepared by the co-sputtering of TiNi and Cu targets during rapid thermal annealing (RTA) were investigated. Crystallization took place in a few seconds at 480 °C. With increasing annealing time (up to 180 s), roughness increased dramatically, and was far more prominent than in films crystallized by conventional thermal annealing (CTA). Although RTA is energy efficient due to the lower annealing time, the film roughness is less ideal than CTA, which may prove limiting in specific applications. The surface and subsurface chemical states of Ti, Ni and Cu was similar for RTA and CTA processed materials, demonstrating they are exposed to comparable redox potentials during annealing. Using X-ray absorption spectroscopy (XAS), it was found that the RTA (180 s) and CTA (1 h) films possessed longer range order. The evolution of nanoscale mechanical properties of the RTA films during rapid thermal annealing was also studied.     

退火温度对磁控溅射Mo薄膜结构和性能的影响

采用磁控溅射技术在石英基体上制备了厚度为600 nm的Mo薄膜,并在不同温度下(400～ 900℃)对其进行退火处理.通过XRD、SEM、四探针测试仪对Mo薄膜的结构和性能进行了分析.结果表明,随着退火温度的升高,(110)晶面择优取向特性增强.Mo薄膜在退火温度为800℃时电阻率达到最小值3.56×10-5 Ω·cm,在900℃退火时薄膜出现宽度约为50 nm的微裂纹且薄膜电阻率较大.