衬底温度和溅射偏压对ZnO:Al透明导电膜结构和光电特性的影响

利用射频磁控溅射法在有机薄膜衬底和7059玻璃衬底上制备出了具有良好附着性的低电阻率的 ZnO:Al透明导电膜。研究了薄膜的结构和光电特性与衬底温度的关系,薄膜为多晶纤锌矿结构,垂直于衬底的 c 轴具有[002]方向的择优取向,薄膜的最低电阻率分别为 1.01×10–3ù·cm 和 8.48×10–4ù·cm,在可见光区的平均透过率分别达到了72%和 85%。并研究了溅射偏压对有机衬底 ZnO:Al 薄膜结构及光电特性影响,最佳负偏压为 60 V。     

退火处理对磁控溅射制备Ga掺杂ZnO薄膜性能的影响

采用磁控溅射法在普通玻璃上制备了Ga掺杂ZnO(GZO)薄膜,研究了退火处理对GZO薄膜组织结构、表面形貌及光电性能的影响,并利用扫描电子显微镜、X射线衍射仪、紫外分光光度计、四探针测试仪等对GZO薄膜的表面形貌、晶体结构、透光率及电阻率等进行测量与表征。结果表明:400~800℃退火对GZO薄膜的生长方式影响较小,所制薄膜均在(002)晶向沿c轴择优取向,退火温度对薄膜表面形貌影响较大,退火温度为600℃时,薄膜表面致密、平整,结晶质量最好,薄膜的透光率超过95%,电阻率最低为4.9×10~(-4)?·cm。     

快速热退火前后ZnO及ZnO/Al薄膜性质的研究

鉴于直流反应溅射制ZAO膜对反应条件敏感,研究发现,经快速热退火(RTA)处理能放宽对反应条件的要求。实验中ZnO及ZnO/Al薄膜用直流反应磁控溅射法制备。选用金属Zn及金属合金Zn/Al靶。经快速热退火(RTA)后,通过XRD,UV-VIS-NIR分光光度计、四探针测方电阻等,研究了经不同温度RTA后ZnO及ZnO/Al薄膜的结晶状况、方电阻、电阻率、可见光透过率等的变化。对传统热退火和RTA进行了比较:经RTA600℃后电阻率减小5~9个数量级,达1×10–3·cm。     

掺杂及工艺条件对室温制备ZnO∶Al性能的影响

采用直流磁控溅射工艺,在室温条件下制备了ZnO∶Al(ZAO)薄膜,研究了Al掺杂量和溅射工艺参数等对ZAO薄膜光电性能的影响.结果表明:Al掺杂量和溅射工艺参数均对薄膜的电阻率有显著影响,在Al掺杂质量分数为3%、溅射功率为100 W以及Ar压强为1.5 Pa的条件下,室温溅射淀积的ZAO薄膜可获得1.4×10-3 Ω*cm的最小电阻率;Al掺杂量和工艺参数对薄膜的透光率均无明显的影响,薄膜的平均透光率在86～90%,但随Al掺杂量和溅射功率的增加,薄膜的截止吸收边均向短波长方向移动.对薄膜优值因子的分析表明,适合采用的Ar压强值在0.6～2.0 Pa.     

真空退火时间对ZAO薄膜的结构与性能的影响

采用射频磁控溅射法制备了Al掺杂ZnO(ZAO)薄膜,研究了真空退火对其组织结构和光电性能的影响规律.结果表明,所制备的ZAO薄膜厚度均匀、组织致密,具有(002)择优取向的六方纤锌矿结构,400℃真空退火后,薄膜晶粒粗大,(002)晶面择优取向性进一步加强.延长退火时间对薄膜的相结构、组织形貌及晶粒大小没有明显的影响.随着退火时间的增加,薄膜的电阻率呈降低趋势,退火3 h时电阻率最低,为2.25×10-3Ω·cm,但长时间退火,电阻率变化不大.薄膜样品的透光率随真空退火时间的延长先降低,后升高,再降低;样品在真空退火4 h时对可见光的平均透过率最佳,在80%以上.退火后,ZAO薄膜的吸收边发生了蓝移现象,光学禁带宽度增大.     

掺铝氧化锌陶瓷靶材的制备及其薄膜的光学性能

以Al(NO3)3.9H2O和ZnO粉体为原料,采用常压烧结方法制备了高致密度和高导电性的ZnO:Al(AZO)陶瓷靶材。研究了烧结温度对AZO靶材微观结构、相对密度和电性能的影响。当Al和Zn的摩尔比为3:100,烧结温度为1 400℃时,所制AZO靶材的致密度达96%,电阻率为2.5×10–2.cm。以烧结温度为1400℃的AZO陶瓷靶为靶材并通过直流磁控溅射在玻璃基片上制备出了高度c轴择优取向的AZO薄膜,其可见光透过率为90%,禁带宽度为3.63 eV,电阻率为1.7×10–3.cm。     

退火对N离子注入ZnO:Al薄膜性能的影响

利用溶胶-凝胶法在(0001)Al2O3衬底上制备了Al/Zn原子比为1%的ZnO:Al薄膜,将能量56keV、剂量1×1017ions/cm2的N离子注入到薄膜中.离子注入后,样品在500～900℃氮气气氛中退火,利用X射线衍射(XRD)、光致发光(PL)、透射谱和四探针研究了退火温度对薄膜性能的影响.结果显示,在800℃以下退火,随退火温度提高,薄膜结晶性能逐渐变好;在600℃以上退火,随退火温度提高,紫外近带边发光峰(NBE)和缺陷相关的深能级可见光发光带都逐渐增强;600℃退火时,样品的电阻率仅为83Ω·cm.     

真空退火温度对GZO/Ag/GZO三层膜性能的影响

室温下在玻璃衬底上,采用射频磁控溅射GZO(Ga掺杂ZnO)膜和离子束溅射Ag膜的方法,制备了GZO/Ag/GZO三层膜,分析了真空退火温度对样品结构、光学、电学性能的影响。结果显示:随着退火温度的升高,Ag层的结构得到明显改善,但GZO层结晶度受到了Ag扩散的影响。经过350℃退火后,样品在可见光区平均透射率达92.63%,电阻率由8.0×10–5Ω·cm降至4.0×10–5Ω·cm。     

中频脉冲磁控溅射制备ZnO:Al透明导电薄膜

采用中频磁控溅射工艺,以2%的Al掺杂的Zn(纯度99.99%)金属材料为靶材制备平面及绒面透明导电ZnO:Al(ZAO)薄膜,系统研究了衬底温度、工作气压和溅射功率等对平面ZAO结构和光电特性的影响,并对湿法腐蚀制备绒面ZAO薄膜进行了介绍。获得了适合太阳电池的高性能薄膜,其电阻率为4.6×10-4Ω·cm,载流子浓度为4.9×1020cm-3,霍尔迁移率为56cm2/V·s,可见光范围内(400~800nm)的平均透过率大于85%。     

掺杂浓度对AZO薄膜结构和性能的影响

采用溶胶–凝胶工艺在玻璃基片上制备出Al3+掺杂型的ZnO(AZO)透明导电薄膜,对薄膜进行了XRD和SEM分析,并对其光电性能作了详细的研究。结果表明薄膜为纤锌矿型结构,呈c轴方向择优生长;薄膜的可见光透过率可达80%以上;Al3+掺杂型的ZnO透明导电薄膜的电阻率为1.5×10–2~8.2×10–2?·cm。     

Electrical and optical properties of sputter-deposited cadmium sulfide thin films optimized by annealing temperature

Cadmium sulfide (CdS) is one of the most widely used materials as a window layer in heterojunction thin film solar cells. Sputtering method for the preparation of CdS thin film was employed for the mass-production of large-area deposited CdS thin films. The electrical and optical properties of sputter-deposited CdS thin films varied with the annealing temperature, which were caused by changes in phase composition, grain size, and stoichiometry of CdS thin films. The improved optical transmittance of 72.25% (at average thickness of 843.93 nm) and the optical band gap energy of 2.43 eV were obtained at the optimum annealing temperature of 400 °C. The resistivity below 10³-order Ω cm and carrier concentration above 10¹⁶ carriers/cm³ are suitable for the requirements of window layers at this optimum annealing temperature.     

Effect of annealing temperature on structural,electrical and optical properties of spray pyrolytic nanocrystalline CdO thin films

Nanocrystalline CdO thin films were prepared onto a glass substrate at substrate temperature of 300 °C by a spray pyrolysis technique. Grown films were annealed at 250, 350, 450 and 550 °C for 2.5 h and studied by the X-ray diffraction, Hall voltage measurement, UV-spectroscopy, and scanning electron microscope. The X-ray diffraction study confirms the cubic structure of as-deposited and annealed films. The grain size increases whereas the dislocation density decreases with increasing annealing temperature. The Hall measurement confirms that CdO is an n-type semiconductor. The carrier density and mobility increase with increasing annealing temperature up to 450 °C. The temperature dependent dc resistivity of as-deposited film shows metallic behavior from room temperature to 370 K after which it is semiconducting in nature. The metallic behavior completely washed out by annealing the samples at different temperatures. Optical transmittance and band gap energy of the films are found to decrease with increasing annealing temperature and the highest transmittance is found in near infrared region. The refractive index and optical conductivity of the CdO thin films enhanced by annealing. Scanning electron microscopy confirms formation of nano-structured CdO thin films with clear grain boundary.     

Optical and electrical properties of nickel oxide thin films synthesized by sol–gel spin coating

Nickel oxide thin films were prepared by the sol–gel technique combined with spin coating onto glass substrates. The as-deposited films were pre-heated at 275 °C for 15 min and then annealed in air at different temperatures. The effects of the annealing temperature on the structural and optical properties of the films are studied. The results show that 600 °C is the optimum annealing temperature for preparation of NiO films with p-type conductivity and high optical transparency. Then, by using these optimized deposition parameters, NiO thin films of various thicknesses were deposited at the same experimental conditions and annealed under different atmospheres. Surface morphology of the films was investigated by atomic force microscopy. The surface morphology of the films varies with the annealing atmosphere. Optical transmission was studied by UV–vis spectrophotometer. The transmittance of films decreased as the thickness of films increased. The electrical resistivity, obtained by four-point probe measurements, was improved when NiO layers were annealed in N₂ atmosphere at 600 °C.     

The structural,optical, and electrical properties of vacuum evaporated Cu-doped ZnTe polycrystalline thin films

We have studied the structural, optical, and electrical properties of thermally evaporated, Cu-doped, ZnTe thin films as a function of Cu concentration and post-deposition annealing temperature. X-ray diffraction measurements showed that the ZnTe films evaporated on room temperature substrates were characterized by an average grain size of 300Å with a (111) preferred orientation. Optical absorption measurements yielded a bandgap of 2.21 eV for undoped ZnTe. A bandgap shrinkage was observed for the Cu-doped films. The dark resistivity of the as-deposited ZnTe decreased by more than three orders of magnitude as the Cu concentration was increased from 4 to 8 at.% and decreased to less than 1 ohm-cm after annealing at 260°C. For films doped with 6–7 at.% Cu, an increase of resistivity was also observed during annealing at 150–200°C. The activation energy of the dark conductivity was measured as a function of Cu concentration and annealing temperature. Hall measurements yielded hole mobility values in the range between 0.1 and 1 cm²/V·s for both as-deposited and annealed films. Solar cells with a CdS/CdTe/ZnTe/metal structure were fabricated using Cudoped ZnTe as a back contact layer on electrodeposited CdTe. Fill factors approaching 0.75 and energy conversion efficiencies as high as 12.1% were obtained.     

Preparation and characterization of cubic lattice ZnS：Na Films with （111） preferred orientation

ZnS：Na thin films with （111） preferred orientation were deposited on glass substrates by vacuum evaporation method. The as-prepared films were annealed in flowing argon at 400--500 ℃ to improve the film crystallinity and electrically activate the dopants. The structural, optical and electrical properties of ZnS：Na films are investigated by X-ray diffrac- tion （XRD）, photoluminescence （PL）, optical transmittance measurements and the four-point probe method. Results show that the as-prepared ZnS：Na films are amorphous, and exhibit （111） preferred orientation after annealing at 400 --500 ℃. The PL emissions at 414 nm and 439 nm are enhanced due to the increase of the intrinsic defects induced by the thermal annealing. However, all the samoles exhibit high resistivitv due to the heavy self-compensation.     

相变型VO2薄膜的制备及其特性的研究

利用反应离子束溅射和后退火工艺制备一种新的相变型VO2薄膜,对该薄膜进行电学测试、XRD和光学透过率的测试。这种工艺制备出的相变型VO2薄膜相变温度更接近室温,XRD显示这种薄膜中有VO2、V2O5成分的存在。对这种薄膜的光学透过率测试表明,低温下薄膜的透过率是高温下薄膜透过率的近5倍。通过实验可以看出,氧气分压、退火温度、退火时间是影响制备新型相变型VO2薄膜的重要因素。     

射频磁控溅射法制备掺锆氧化锌透明导电薄膜

利用射频磁控溅射法在室温下制备出了掺锆氧化锌(ZnO∶Zr)透明导电薄膜。研究了溅射压强对ZnO∶Zr薄膜表面形貌、结构、光学和电学性能的影响。结果表明:ZnO∶Zr薄膜为六角纤锌矿结构的多晶薄膜,且具有c轴择优取向,溅射压强对薄膜电阻率有显著影响,压强为1.5Pa时,电阻率具有最小值1.77×10–3Ω·cm。所制备的ZnO∶Zr薄膜具有良好的附着性能,在可见光区平均透过率超过93%。     

退火温度对ZnO掺杂ITO薄膜性能的影响

利用电子束蒸镀方法,在K8玻璃衬底上沉积ZnO掺杂ITO(ZnO-ITO)与ITO薄膜。研究不同退火温度对ZnO-ITO薄膜的微观结构的影响;对比分析了在不同退火温度条件下,ZnO-ITO和无掺杂ITO薄膜的光电性能。结果发现,ZnO-ITO薄膜具有较大的晶粒尺寸,随着退火温度的上升,晶体结构得到改善,表面粗糙度减小,薄膜的光电性能显著提高。ZnO-ITO薄膜经过500℃退火后得到最佳的综合性能,其表面均方根粗糙度(RMS)为32.52nm,电阻率为1.43×10-4Ω.cm;对442nm波长的光,透射率可达98.37%;与ITO薄膜相比,ZnO-ITO薄膜具有显著的抗PEDOT:PSS溶液腐蚀的能力。     

Investigation of optical and electronic properties in Al–Sn co-doped ZnO thin films

Al-Sn co-doped ZnO thin films were deposited onto quartz substrates by sol-gel processing. The surface morphology and electrical and optical properties were investigated at different annealing temperatures. The surface morphology showed a closely packed arrangement of crystallites in all the doped films. As prepared co-doped films show a preferred orientation along an (0 0 2) plane. This preferred orientation was enhanced by increasing the annealing temperature to between 400 °C and 500 °C, but there was a shift to the (1 0 1) plane when the annealing temperature rose above 500 °C. These samples show, on average, 91.2% optical transmittance in the visible range. In this study, the optical band gap of all the doped films was broadened compared with pure ZnO, regardless of the different annealing temperature. The carrier concentration and carrier mobility of the thin films were also investigated.