ABSTRACT
The hydrothermal growth of crystalline ß-V2O5 microstructures was performed on fluorine doped tin dioxide glass substrates using oxalic acid to adjust the pH of the solution for various deposition periods. It was observed that the sample grown for 48 h at pH 2 exhibited the best electrochemical response in terms of the highest specific charge and capacitance, being 772 C g(-1) and 386 F g(-1) respectively. The importance of achieving high crystalline quality samples and increased surface area toward the improvement of the electrochemical performance of ß-V2O5 is highlighted.
ABSTRACT
The results of electron field emission from single walled carbon nanotubes (SWCNTs) mats deposited on different composite films of SWCNTs and poly(3-octylthiophene) (P3OT) semiconducting polymer are presented. Three different structures were tested: (a) dense and sparse SWCNT mats on n+ -Si; (b) SWCNT mats on composite films with different SWCNT-P3OT ratios; (c) composite films with different SWCNT-P3OT ratios on n+ -Si. The experiments show that there is a critical SWCNT-P3OT concentration in which the field emission stability of SWCNT mats is remarkably improved with a small reduction in the emission threshold compared to the optimum pristine SWCNT film. The contribution of the composite film morphology as well as the role of polymer-nanotube interaction on the emission performance are evaluated. The physical mechanism behind the stability of composite field emitters is also discussed.
