离子束溅射制备CdS多晶薄膜及性能研究

采用离子束溅射的方法在玻璃衬底上制备CdS多晶薄膜,研究了沉积过程中基底温度(100～400℃)与薄膜厚度(35～200nm)对其微结构与光电性能的影响。结果表明,不同基底温度下制备的CdS薄膜均属于六方相多晶结构且具有(002)择优取向生长特征;随着基底温度的升高,(002)特征衍射峰强度增加,半高宽变小相应薄膜结晶度增大,有利于颗粒的生长;分析CdS薄膜的光谱图线可知,薄膜在可见光区平均透射率高于75%,光学带隙值随着基底温度升高而增大(2.33～2.42eV)且薄膜电阻高达109Ω;在基底温度为400℃条件下制备不同厚度的CdS薄膜,发现(50～100nm)较薄的CdS薄膜具有较为明显的六方相CdS多晶薄膜结构、较优光学性能和高电阻值,满足CIS基太阳电池中缓冲层材料的基本要求。     

离子束反应溅射ZnO薄膜的晶体结构及光学、电学性质研究

采用离子束反应溅射法在玻璃基片上沉积了一系列ZnO薄膜样品.通过对薄膜样品XRD谱的分析,发现基片温度和溅射氧分压是同时影响ZnO薄膜沿c轴择优取向生长的重要因素.在基片温度350 ℃,氧分压1.3 的溅射条件下,得到了完全沿c轴取向生长的只有(002)晶面的ZnO薄膜.薄膜的吸收光谱测量结果表明,基片温度和氧分压对ZnO薄膜的光学禁带宽度有重要影响.不同氧分压、不同基片温度制备的薄膜电阻率相差很大.     

硫化温度对CuInS2吸收层薄膜微结构的影响

采用电沉积-硫化法制备了CuInS2(CIS)薄膜.用X射线衍射仪(XRD)、原子力显微镜(AFM)和能谱仪(EDS)等实验手段对CIS薄膜的晶体结构、形貌和组分进行了表征.结果表明:在500～560℃硫化温度范围内制备的CIS薄膜表面均生成金属性CuxS二元相,后续的KCN刻蚀处理CuxS二元相可去除.硫化温度为540℃制得的CIS薄膜高质量结晶、具有[112]择优取向,适合于制备CIS薄膜太阳能电池吸收层.     

新型工艺制备ZnO薄膜的结构与形貌研究

采用了一种新型工艺制备ZnO薄膜。新工艺采用二步法,首先在N型Si(100)衬底上用离子束沉积溅射一层金属Zn膜,然后通过热氧化金属Zn膜制备ZnO薄膜。通过X射线衍射、原子力显微镜对不同制备工艺下的ZnO薄膜进行结构与形貌的分析比较。研究表明,Zn膜的离子束溅射沉积时间、热氧化时间和辅助枪的离子束对热氧化后的ZnO薄膜再轰击处理对ZnO薄膜的结构与形貌都会产生影响。     

硒化温度对CuInSe2薄膜性能的影响

采用中频交流磁控溅射方法沉积Cu-In薄膜,并采用固态源硒化方法制备CuInSe2(CIS)薄膜,考察了硒化温度对CIS薄膜性能的影响.采用SEM和EDS观察和分析了它们的表面形貌和成分,采用XRD表征了薄膜的组织结构,采用霍尔测试仪测量了薄膜的载流子浓度和霍尔迁移率.结果表明,Cu-In薄膜由In和Cu11In9两相组成,在不同的硒化温度下制备的CIS薄膜,均具有单一的黄铜矿CuInSe2相结构.随着硒化温度的升高,CIS薄膜的晶粒直径增大,当硒化温度达到550℃时,晶粒直径已接近于2 μm.硒化温度继续升高,晶粒之间出现孔洞和缝隙等缺陷.530℃的硒化温度下制得的弱p型CIS薄膜,最符合CuInSe2的化学计量比,最适于制备太阳能电池吸收层.     

离子束溅射法制备碳氮薄膜及其结构表征

采用离子束溅射沉积技术,对不同氮离子束能量情况下制备的氮化碳薄膜,进行了拉曼(Raman)和红外光谱(FT-IR)分析,并采用透射电子显微镜(TEM)分析其表面形貌,研究所制备薄膜的化学组成和键合结构。结果显示:随着氮离子束能量增大,氮碳薄膜的沉积速率减小,薄膜结构中sp2含量增大,薄膜有序度增加,另外薄膜结构的团簇尺寸大幅下降,团簇趋于均匀分布。     

工艺参数对离子束溅射ZnO∶Al薄膜结构与性能的影响

以ZnO(掺杂2%Al2O3)陶瓷靶作为靶材,采用离子束溅射技术在BK7玻璃基底上制备AZO透明导电薄膜。研究不同工艺参数对ZnO∶Al(AZO)薄膜结构与光电性能的影响。结果表明,不同等离子体能量下制备的AZO薄膜均出现ZnO(002)特征衍射峰,具有纤锌矿结构且c轴择优取向;AZO薄膜的结晶质量和性能对基底温度有较强的依赖性,只有在适当的基底温度下,可改善结晶程度且利于颗粒的生长,呈现较低的电阻率;不同厚度的AZO薄膜均出现较强的ZnO(002)特征衍射峰且随着厚度的增加,ZnO(110)峰强度不断加强,相应晶粒尺寸变大,但缺陷也随之增多;同时得出利用离子束溅射方法制备AZO薄膜的最佳工艺为:等离子体能量为1.3 keV、基底温度200℃和沉积厚度为420 nm,该参数下制备的薄膜结晶程度较高、生长的颗粒较大,相应薄膜的电阻率较低且薄膜透射率在可见光区均达到80%以上。     

离子束溅射BST薄膜的制备及结构分析

本文采用离子束溅射的方法制备了不同衬底温度下的BST薄膜,用X射线、Raman、SPM等技术对晶体结构及微观形貌进行表征,研究了离子束溅射制备BST的工艺.     

利用脉冲直流磁控溅射制备ZnO:Al薄膜的研究

利用中频脉冲直流磁控溅射法制备了平面ZnO:Al(AZO)透明导电薄膜,研究了沉积压力、衬底温度和溅射功率对AZO薄膜光电性能、薄膜稳定性的影响.结果表明:在较低沉积压力、衬底温度及溅射功率下,可获得具有低电阻率、高透过率、高稳定性的AZO薄膜.     

双离子束溅射沉积二氧化硅薄膜

利用双离子束溅射沉积技术,在锗、硅、K9玻璃、不锈钢基底上沉积了二氧化硅薄膜。考察了不同束辐照条件下二氧化硅薄膜的电阻率、折的率、红外吸收谱和显微组织结构。     

反应磁控溅射法制备氧化铟锡钽薄膜

利用掺锡氧化铟(ITO)靶和Ta2O5靶双靶共溅法制备了氧化铟锡钽(ITTO)薄膜,研究了在不同衬底温度和退火温度下ITTO薄膜的微结构和光电性能。ITTO薄膜具有更好的晶化程度和较低的表面粗糙度,不同的处理过程导致了晶面择优取向的转变。室温下制备的ITTO薄膜展示了较好的光电性能,提高衬底温度和合理的退火处理可以显著地提高薄膜的光电特性。载流子浓度对于近红外反射、近紫外吸收和光学禁带宽度具有重要的影响。ITTO薄膜具有较宽的光学禁带宽度。在优化制备条件下,可以获得方阻10～20Ω/□、可见光透过率大于85%以及光学禁带宽度大于4.0eV的ITTO薄膜。     

衬底温度和氢气退火对ZnO:Al薄膜性能的影响

采用射频磁控溅射法在石英玻璃衬底上制备了性能良好的透明导电ZnO:Al薄膜,并研究了衬底温度和氢气退火对薄膜结构和光电性能的影响。结果表明,衬底加热可以改善薄膜结晶质量和c轴择优取向,减小内应力,并提高其电学性能。经稀释氢气退火后,500℃沉积的薄膜电阻率由9.4×10-4Ω.cm减小到5.1×10-4Ω.cm,迁移率由16.4cm2.V-1.s-1增大到23.3 cm2.V-1.s-1,载流子浓度由4.1×1020cm-3提高到5.2×1020cm-3,薄膜的可见光区平均透射率仍达85%以上。禁带宽度随着衬底温度的升高和氢气退火而展宽。     

退火温度对硅基溅射铜膜应力的影响

采用光学相移法 ,对Si基片上Cu膜应力随退火温度的变化进行了研究。研究表明 :随退火温度的升高 ,Cu膜应力减小 ,2 0 0℃时平均应力减小为 - 0 2 6 1× 10 8Pa,且应力分布均匀 ,在选区范围内应力差仅为 2 2 4 4× 10 8Pa。同时用X射线衍射技术测量分析了Cu膜经过不同退火温度热处理后的微结构组织 ,研究了Cu膜的微结构对其应力的影响     

The influence of annealing temperature on the structural, electrical and optical properties of ion beam sputtered CuInSe2 thin films

CuInSe₂ (CIS) thin films were prepared by ion beam sputtering deposition of copper layer, indium layer and selenium layer on BK7 glass substrates followed by annealing at different temperatures for 1 h in the same vacuum chamber. The influence of annealing temperature (100-400 °C) on the structural, optical and electrical properties of CIS thin films was investigated. X-ray diffraction (XRD) analysis revealed that CIS thin films exhibit chalcopyrite phase and preferential (112) orientation when the annealing temperature is over 300 °C. Both XRD and Raman show that the crystalline quality of CIS thin film and the grain size increase with increasing annealing temperature. The reduction of the stoichiometry deviation during the deposition of CIS thin films is achieved and the elemental composition of Cu, In and Se in the sample annealed at 400 °C is very near to the stoichiometric ratio of 1:1:2. This sample also has an optical energy band gap of about 1.05 eV, a high absorption coefficient of 10⁵ cm⁻¹ and a resistivity of about 0.01 Ω cm.     

N掺杂Cu2O薄膜的低温沉积及快速热退火研究

采用氧化亚铜(Cu_2O)陶瓷靶,利用射频磁控溅射沉积法在氮气和氩气的混合气氛下制备了N掺杂Cu_2O(Cu_2O∶N)薄膜,并在N_2气氛下对薄膜进行了快速热退火处理,研究了N_2流量和退火温度对Cu_2O∶N薄膜的生长行为、物相结构、表面形貌及光电性能的影响。结果显示,在衬底温度300℃、N_2流量12sccm条件下生长的薄膜为纯相Cu_2O薄膜;在N_2气氛下对预沉积薄膜进行快速热退火处理不影响薄膜的物相结构,薄膜的结晶质量随退火温度(450℃)的升高而显著改善;快速热退火处理能改善薄膜的结晶质量和缺陷,降低光生载流子的散射,增强载流子的传输,预沉积Cu_2O∶N薄膜经400℃退火处理后展示出较好的电性能,薄膜的霍尔迁移率(μ)为27.8cm~2·V~(-1)·s~(-1)、电阻率(ρ)为2.47×10~3Ω·cm。研究表明低温溅射沉积和快速热退火处理能有效改善Cu_2O∶N薄膜的光电性能。     

Characterization of stepwise flash-evaporated CuInSe2 films

CuInSe₂ (CIS) films were deposited by stepwise flash evaporation from polycrystalline powder source onto glass substrates held at various temperatures ranging from 100 to 560 K. The phase purity and microstructure were analyzed by transmission electron microscopy. The investigations show that films grown at 300 K and below were amorphous, whereas those grown at 370 K and above were polycrystalline in nature. The grain size in polycrystalline films were found to improve with increase in substrate temperature and during post-deposition annealing. The films had near stoichiometric composition as revealed by Rutherford backscattering spectrometry. Analysis of the optical transmittance spectra of CIS films deposited at 520 K yielded a value of ∼0.97 eV for the fundamental band gap.     

Effect of heat treatment on characteristics of nanocrystalline ZnO films by electron beam evaporation

Zinc oxide thin films have been grown on glass substrate at room temperature by electron beam evaporation and then were annealed in annealing pressure 600 mbar at different temperatures ranging from 250 to 550 °C for 30 min. Electrical, optical and structural properties of thin films such as electrical resistivity, optical transmittance, band gap and grain size have been obtained as a function of annealing temperature. X-ray diffraction has shown that the maximum intensity peak corresponds to the (002) predominant orientation for ZnO films annealed at various temperatures. The full width at half maximum, decreases after annealing treatment which proves the crystal quality improvement. Scanning electron microscopy images show that the grain size becomes larger by increasing annealing temperature and this result agrees with the X-ray diffraction analysis.     

Low cost CuInSe2 thin films production by stacked elemental layers process for large area fabrication of solar cell application

Low cost deposition of large area CuInSe₂ (CIS) thin films have been grown on Mo-coated glass substrate by simple and economic stacked elemental layer deposition technique in vacuum. The grown parameters such as concentration of Cu, In and Se elements have been optimized to achieve uniform thin film in vacuum chamber. The as-grown Cu/In/Se stacked layers have been annealed at 200 °C and 350 °C for 1 h in air ambient. The as-grown and annealed films have been further subjected to characterization by X-ray diffraction (XRD), optical absorption, atomic force microscopy (AFM) and I-V measurement techniques. XRD patterns revealed that as-grown Cu/In/Se stacked layers represent amorphous nature while annealed CIS film reproduces nano-polycrystalline nature with chalcopyrite structure. The optical band gap of annealed films increases with respect to air annealing which confirms the reduction of crystallite size. Surface morphology of as-grown Cu/In/Se stacked layers and annealed CIS thin films have been confirmed by AFM images. The electrical measurements show enhancement of conductivity which is useful for solar cell application.     

A new technique for growing epitaxial films of Pb1−xSnxTe

An improved technique has been found for the vacuum deposition of epitaxial films of Pb_1?xSn_xTe on cleaved KC1 substrates. In order to nucleate a crystalline film which adheres well to the substrate, the substrate temperature is initially raised to only 280°C. After a one-micron film has grown, the substrate temperature is then raised to 400°C and maintained there for all subsequent film growth. This increase in substrate temperature is needed to achieve the highest quality optical surfaces. Results on both as-grown and annealed films are presented. One result of our annealing program has been the achievement of the lowest reported carrier concentration in films with Sn fractions greater than 0.3.     

Annealing effects of sapphire substrate on the structure and properties of ZnO films grown via pulsed laser deposition

The structure, morphology, and properties of ZnO films were examined in relation to an annealed sapphire substrate prepared via pulsed laser deposition. The annealing effects of the sapphire substrate on the ZnO films were studied via X-ray diffraction (XRD), atomic-force microscopy (AFM), and photoluminescence (PL) measurements. The XRD patterns and PL spectra results showed that the optical quality of the ZnO films was significantly affected by the annealing temperature of the sapphire substrate. The optimum annealing temperature of the sapphire substrate was 1400 degrees C. Atomically-flat-surface and high-density atomic steps were formed after annealing treatment, which were qualified to be good nucleation sites for ZnO film growth.