Metal oxide double layer capacitors by electrophoretic deposition of metal oxides. Fabrication, electrical characterization and defect analysis using positron annihilation spectroscopy
Metal oxide double layer capacitors by electrophoretic deposition of metal oxides. Fabrication, electrical characterization and defect analysis using positron annihilation spectroscopy
复制标题
DOI：
10.1039/c8tc03330g
复制
发表时间：
2018-09-21
影响因子：
6.4
通讯作者：
Schneider, Joerg J.
中科院分区：
文献类型：
--
作者：
Hoffman, Rudolf C.;Koslowski, Nico;Schneider, Joerg J.
采用电泳法在ITO/玻璃电极上制备了纳米ZnO薄膜。微波辅助热处理的烷基乙酰乙酸锌导致在电泳沉积过程中形成稳定的分散体。通过首先在较低电压下开始电泳并在沉积的后期阶段增加到较高电压，可以实现均匀和光滑的涂层。ZnO/ITO双层被集成在金属氧化物半导体（MOS）电容器，通过完成设置与旋涂PMMA介电层和金触点。MOS电容器显示出具有负微分电阻区域的IV曲线，表明在ZnO晶粒和ZnO/PMMA界面处都存在电荷捕获。多普勒展宽正电子湮没（DB-PAS）和正电子湮没寿命谱（帕尔斯）被用来表征沉积的ZnO层内的点缺陷和空隙空间，这允许洞察到的薄膜组合物的体组成。帕尔斯显示存在0.5至1.5 nm范围内的微孔。
Films consisting of nanocrystalline ZnO were deposited on ITO/glass electrodes using an electrophoretic process. The microwave-assisted thermolysis of zinc alkyl-acetoacetates resulted in the formation of stable dispersions for the electrophoretic deposition procedure. Uniform and smooth coatings could be achieved by starting the electrophoresis at lower voltages first and increasing to higher voltages at later stages of the deposition. The ZnO/ITO double layers were integrated in metal oxide semiconductor (MOS) capacitors by completing the set-up with a spin-coated PMMA dielectric layer and gold contacts. The MOS capacitors showed IV curves with a region of negative differential resistance, indicating charge trapping, both in the ZnO grains and at the ZnO/PMMA interface. Doppler broadening positron annihilation (DB-PAS) and positron annihilation life time spectroscopy (PALS) were employed to characterize the point defects and void space within the deposited ZnO layer which allowed to give insight into the bulk composition of the film composition. PALS revealed the presence of micropores in the range of 0.5 to 1.5 nm.