Effects of Thermal Pressing on ZnO Nanoparticle Layers Deposited by Drop Casting

Abstract

ZnO nanoparticle (NP) layers were formed using a simple drop casting process. Applying thermal pressing clearly improved the surface morphology and electrical properties of the as-deposited ZnO NP layers as well as significantly enhanced the transistor characteristics of the NP layers. The effects of thermal pressing on the film surface properties were evaluated by X-ray photoelectron spectroscopy, Kelvin probe microscopy, and photoluminescence spectroscopy. Results suggest that thermal pressing improved the transistor characteristics by decreasing NP surface defects such as oxygen vacancies.

Characterization of nitrogen ion implanted TiO2 photocatalysts by XAFS and XPS

“…On the other hand, the XANES spectrum of TiO 2 -N(1) showed a distinct single peak around 401 eV. This peak could be empirically attributed to formation of NOx (1 6 x 6 2) species [5,9,10]. Thus, N K-edge XANES spectra clearly indicated the difference in the chemical states of implanted nitrogen between TiO 2 -N(1) and TiO 2 -N(5), although O K-and Ti L 2,3 -edge XANES spectra showed no remarkable difference among these samples.…”

“…In the UV-vis spectra of N + implanted TiO 2 samples, the absorbance in the visible-light region from 420 nm to 540 nm increased with the fluence of nitrogen, suggesting the generation of visible light response by the N + implantation [5].…”

Effective nitrogen doping into TiO2 (N-TiO2) for visible light response photocatalysis

“…On the other hand, the XANES spectrum of TiO 2 -N(1) showed a distinct single peak around 401 eV. This peak could be empirically attributed to formation of NOx (1 6 x 6 2) species [9].…”

“…In the UV-vis spectra of N + implanted TiO 2 samples, the absorbance in the visible-light region from 420 nm to 540 nm increased with the fluence of nitrogen, suggesting the generation of visible light response by the N + implantation [9].…”

“…Except the 400 eV peak, the N 1s peaks observed for TiO 2 -N(1) and TiO 2 -N(5) can be divided into two groups, one at 396 eV and another at 402-404 eV. We assigned the N 1s peak around 396 eV to nitrogen substituting O sites of TiO 2 [9][10][11] and the peak at 402-404 eV to NOx species [9][10][11]. It is interesting to note that XPS spectrum for the photocatalytically active TiO 2 -N(5) exhibits only one peak at 396 eV, while those for the photocatalytically inactive TiO 2 -N(1) show two peaks.…”