2 research outputs found
Impact of the Cation Composition on the Electrical Performance of Solution-Processed Zinc Tin Oxide Thin-Film Transistors
This
study examined the structural, chemical, and electrical properties
of solution-processed (Zn,Sn)ÂO<sub>3</sub> (ZTO) films with various
Sn/[Zn+Sn] ratios for potential applications to large-area flat panel
displays. ZTO films with a Zn-rich composition had a polycrystalline
wurtzite structure. On the other hand, the Sn-rich ZTO films exhibited
a rutile structure, where the Zn atom was speculated to replace the
Sn site, thereby acting as an acceptor. In the intermediate composition
regions (Sn/[Zn+Sn] ratio from 0.28 to 0.48), the ZTO films had an
amorphous structure, even after annealing at 450 °C. The electrical
transport properties and photobias stability of ZTO thin film transistors
(TFTs) were also examined according to the Sn/[Zn+Sn] ratio. The optimal
transport property of ZTO TFT was observed for the device with an
amorphous structure at a Sn/[Zn+Sn] ratio of 0.48. The mobility, threshold
voltage, subthreshold swing, and on/off current ratio were 4.3 cm<sup>2</sup>/(V s), 0 V, 0.4 V/decade, and 4.1 × 10<sup>7</sup>,
respectively. In contrast, the device performance for the ZTO TFTs
with either a higher or lower Sn concentration suffered from low mobility
and a high off-state current, respectively. The photoelectrical stress
measurements showed that the photobias stability of the ZTO TFTs was
improved substantially when the ZTO semiconducting films had a lower
oxygen vacancy concentration and an amorphous structure. The relevant
rationale is discussed based on the phototransition and subsequent
migration mechanism from neutral to positively charged oxygen vacancies
Preliminary PET Study of <sup>18</sup>F‑FC119S in Normal and Alzheimer’s Disease Models
To evaluate the efficacy of <sup>18</sup>F-FC119S as a positron
emission tomography (PET) radiopharmaceutical for the imaging of Alzheimer’s
disease (AD), we studied the drug absorption characteristics and distribution
of <sup>18</sup>F-FC119S in normal mice. In addition, we evaluated
the specificity of <sup>18</sup>F-FC119S for β-amyloid (Aβ)
in the AD group of an APP/PS1 mouse model and compared it with that
in the wild-type (WT) group. The behavior of <sup>18</sup>F-FC119S
in the normal mice was characteristic of rapid brain uptake and washout
patterns. In most organs, including the brain, <sup>18</sup>F-FC119S
reached its maximum concentration within 1 min and was excreted via
the intestine. Brain PET imaging of <sup>18</sup>F-FC119S showed highly
specific binding of the molecule to Aβ in the cortex and hippocampus.
The brain uptake and binding values for the AD group were higher than
those for the WT group. These results indicated that <sup>18</sup>F-FC119S would be a candidate PET imaging agent for targeting Aβ
plaque