钨钒共溅热致变色薄膜的制备及其红外光学性能

为解决VO2薄膜相变温度过高,热滞回线温宽过大以及掺杂后红外透过率变低等问题,开展了低成本钨钒共溅热致变色薄膜制备工艺的探索。先在室温条件下采用磁控共溅射的方法于玻璃基片上制备得到含钨量为1.4%的金属薄膜,再在空气中采用后退火工艺使金属薄膜充分氧化为热致变色薄膜。对薄膜样品的物理结构和光学性能进行了分析,发现钨钒共溅没有改变VO2薄膜在玻璃表面择优取向生长,但显著改变了VO2薄膜的表面形貌特征。观察到钨钒共溅热致变色薄膜的相变温度较普通VO2薄膜从68℃降低至40℃,热滞回线温宽由6℃缩小为3℃,低温半导体相的红外透过率分别为62%和57%。结果表明,钨钒共溅可达到相变温度降低,热滞回线温宽变窄,掺杂前后红外透过率变化不大之目的。     

二元不互溶Cu-Ta体系非晶相的形成

利用X射线衍射(XRD)、高分辨透射电子显微术(HRTEM)和X射线能谱(EDS)研究了共溅射Cu-Ta薄膜中非晶相的形成.结果表明,共溅射Cu-Ta薄膜为非晶相,但是其中存在着纳米尺度的Cu晶粒和富Cu的非晶纳米颗粒,即存在纳米尺度的相分离.正的混合热是导致Cu-Ta二元不互溶体系非晶态薄膜相分离的本质原因.     

共溅射法制备AZO薄膜及其光电性能的研究

目的研究Al靶直流溅射功率对Al掺杂ZnO(AZO)薄膜光电性能的影响。方法以金属Al和ZnO陶瓷作为靶材,采用直流与射频双靶磁控共溅射的方法,在玻璃基片上制备AZO薄膜。通过改变Al靶直流溅射功率,获得不同的薄膜。采用X射线衍射仪(XRD)、光电子能谱仪(XPS)、原子力显微镜(AFM)、紫外-可见分光光度计(UV-Vis)、四探针测试仪,对薄膜的微观形貌结构及光电性能进行表征和分析。结果所制备的AZO薄膜均具有C轴取向生长的六角纤锌矿结构,在可见光区域平均透过率超过90%,AZO薄膜的吸收边相比于ZnO薄膜出现了蓝移。当Al靶溅射功率为18 W时,AZO薄膜的最低电阻率为2.49×10~(-3)?·cm,品质因子为370.2 S/cm。结论 Al直流溅射功率对AZO薄膜光电性能的影响较大,溅射功率为18 W时,制备的AZO薄膜性能最优。     

Tunable near-infrared epsilon-near-zero and plasmonic properties of Ag-ITO co-sputtered composite films

Series of co-sputtered silver-indium tin oxide (Ag-ITO) films are systematically fabricated. By tuning the atomic ratio of silver, composite films are manifested to have different microstructures with limited silver amount (<3 at.%). Two stages for film morphology changing are proposed to describe different status and growth mechanisms. The introduction of silver improves the preferred orientations of In₂O₃ component significantly. Remarkably, dielectric permittivity of Ag-ITO films is highly adjustable, allowing the cross-over wavelengths λ_c to be changed by more than 300 nm through rapid post-annealing, and thus resulting in tunable epsilon-near-zero and plasmonic properties in the near-infrared region. Lower imaginary permittivity compared with pure metal films, as well as larger tunability in λ_c than pure ITO films suggest the potentiality of Ag-ITO films as substituted near-infrared plasmonic materials. Extended Maxwell-Garnett model is applied for effective medium approximation and the red-shifting of epsilon-near-zero region with the increase of silver content is well-fitted. Angle-variable prism coupling is carried out to reveal the surface plasmon polariton features of our films at optical communication wavelength. Broad dips in reflectance curves around 52–56° correspond to the SPP in Ag-ITO films.