两步法制备聚酰亚胺柔性衬底的ZnO纳米阵列

Synthesis of ZnO nanorod arrays on polymide flexible substrate by two-step method

在低温条件下采用两步法在聚酰亚胺(PI)薄膜上制备ZnO纳米阵列。首先,在90℃条件下,用旋涂法在柔性PI衬底上生长1层ZnO缓冲层,然后,在柔性衬底上用水热法制备ZnO纳米阵列。研究十二烷基磺酸钠(SDS)的最佳用量并优化ZnO的制备条件。对PI薄膜进行酸碱处理以提高其表面粗糙度和润湿性能,通过锌浓度测定仪测量SDS的最佳用量为0.70 g。样品的形貌、尺寸和结构通过傅里叶红外光谱仪(FT-IR)、原子力显微镜(AFM)、场发射扫描电子显微镜(FESEM)和X线衍射仪(XRD)进行表征。结果表明:ZnO纳米棒为六角纤锌矿结构,沿C轴方向择优生长,反应浓度与反应时间影响纳米棒阵列的直径与垂直度。ZnO阵列的光致发光(PL)性能表明,在380 nm有紫外光(UV)发射峰,在450 nm有蓝光发射峰。380 nm处的UV发射峰由自由激子复合引起,450 nm处的蓝光发射峰可能由电子的跃迁引起。

ZnO nanorod arrays were synthetized by a two-step method on polymide（ PI） substrate at low temperatures. The solution was spin-coated on the PI substrate,the Zn / sodiumdodecylsulphate（ SDS）composite was dried at 90 ℃. The seed layer was grown to ZnO nanorods by hydrothermal synthesis. The optimum amount of the SDS and the preparation conditions of ZnO were investigated. Polyimide films were modified by acid-base surface treatment to improve the surface roughness. The optimum content of SDS was 0. 70 g measured by zinc concentration detector. The morphology,the size and the crystal structure of the samples were characterized by Fourier transform infrared spectrometer（ FT-IR）,atomic force microscope（ AFM）,field emission scanning electron microscopy（ FESEM）,and X-ray diffraction（ XRD）. Results indicated that the nanorods had wurtzite（ hexagonal） structure and the nanorods grew along the C axis direction of the ZnO crystallites. The diameter of the ZnO and the verticality of the array were affected by the reactant concentration and the reaction time. The ultraviolet light（ UV） peak at 380 nm and the blue peak at 450 nm were observed in the photoluminescence（ PL） spectrum of the ZnO micro-nano arrays. The UV peak at 380 nm was caused by free exciton recombination and the blue emission was attributed to electron transition from the extended state to the valance band.