ALD Al2O3 gate dielectric on the reduction of interface trap density and the enhanced photo-electric performance of IGO TFT.

The amorphous indium gallium oxide thin film transistor was fabricated using a cosputtering method. Two samples with different gate dielectric layers were used as follows: sample A with a SiO2 dielectric layer; and sample B with an Al2O3 dielectric layer. The influence of the gate dielectrics on the electric and photo performance has been investigated. Atomic layer deposition deposited the dense film with low interface trapping density and effectively increased drain current. Therefore, sample B exhibited optimal parameters, with an I on/I off ratio of 7.39 × 107, the subthreshold swing of 0.096 V dec-1, and µ FE of 5.36 cm2 V-1 s-1. For ultraviolet (UV) detection, the UV-to-visible rejection ratio of the device was 3 × 105, and the photoresponsivity was 0.38 A W-1 at the V GS of -5 V.

Impact of Oxygen Vacancy on the Photo-Electrical Properties of In2O3-Based Thin-Film Transistor by Doping Ga.

In this study, amorphous indium gallium oxide thin-film transistors (IGO TFTs) were fabricated by co-sputtering. Three samples with different deposition powers of the In2O3 target, namely, sample A with 50 W deposition power, sample B with 60 W deposition power, and sample C with 70 W deposition power, were investigated. The device performance revealed that oxygen vacancies are strongly dependent on indium content. However, when the deposition power of the In2O3 target increased, the number of oxygen vacancies, which act as charge carriers to improve the device performance, increased. The best performance was recorded at a threshold voltage of 1.1 V, on-off current ratio of 4.5 × 106, and subthreshold swing of 3.82 V/dec in sample B. Meanwhile, the optical properties of sample B included a responsivity of 0.16 A/W and excellent ultraviolet-to-visible rejection ratio of 8 × 104. IGO TFTs may act as photodetectors according to the results obtained for optical properties.

Excited state luminescence of multi-(5-phenyl-1,3,4-oxadiazo-2-yl)benzenes in an electron-donating matrix: exciplex or electroplex?

Multi-(5-phenyl-1,3,4-oxadiazo-2-yl)benzenes show emission in organic solvents from ultraviolet to blue (339-447 nm). The reduction potentials E(1/2)(red) cover a large range of -2.11 V for 2,5-diphenyl-1,3,4-oxadiazole to -0.76 V for 1,2,3,4,5,6-hexa(5-phenyl-1,3,4-oxadiazo-2-yl)benzene. An unexpectedly wide spectral range of the oxadiazole (OXD) exciplex emissions in PVK is observed, ranging from 406 to 603 nm. The OXDs also exhibit similar electroluminescence (EL) when blended into polyvinylcarbazole (PVK). A linear correlation between the lambda(max) of the electroluminescence and photoluminescence is observed, implying that the emission mechanisms in both processes are similar. In addition, the linear correlation between the E(1/2)(red) versus lambda(max) of EL (eV) reflected that the term of the charge-transfer configuration of the contact electron-hole pair plays a major role in the exciplex emission. The exciplex EL of 1,2,5-tri(5-phenyl-1,3,4-oxadiazo-2-yl)benzene (5) could be as high as 1.0 cd/A. Since the exciplex emission usually has a large Stokes shift, this provides a window for us to generate duo emissions for near white light EL with high efficiency. Among the devices we tried, the device of PVK/2-tert-butylphenyl-5-biphenyl-1,3,4-oxadiazole/5/2,5,8,11-tetra-tert-butylperylene (100:40:40:4) gave EL with good current efficiency of 1.63 cd/A.

The unusual electrochemical and photophysical behavior of 2,2'-bis(1,3,4-oxadiazol-2-yl)biphenyls, effective electron transport hosts for phosphorescent organic light emitting diodes.

The fluorescence and phosphorescence of 2,2'-bis(5-phenyl-1,3,4-oxadiazol-2-yl)biphenyl shows good spectral matching with the absorption spectra of the MLCT1 and MLCT3 transitions of Ir(ppy)3. The red-shift of the 0-0 band in the phosphorescence at 77 K is due to the intramolecular pi-pi interactions between the oxadiazole side chains. Maximum brightness of 43,000 cd/m2 with an efficiency of 26 cd/A at 200 cd/m2 was achieved when BOBP was used as the host material for Ir(ppy)3 in the PHOLED study. [structure: see text].

Peripheral sympathectomy for Raynaud's phenomenon: a salvage procedure.

We retrospectively reviewed the effectiveness of peripheral sympathectomy for severe Raynaud's phenomenon. In this study, a total of 14 digits from six patients with chronic digital ischemic change were included. All patients had pain, ulcer, or gangrenous change in the affected digits and were unresponsive to pharmacologic or other nonsurgical therapies. In all cases, angiography showed multifocal arterial lesions, so microvascular reconstruction was unfeasible. Peripheral sympathectomy was performed as a salvage procedure to prevent digit amputation. The results were analyzed according to reduction of pain, healing of ulcers, and prevention of amputation. In 12 of the 14 digits, the ulcers healed and amputation was avoided. In the other two digits, the ulcers improved and progressive gangrene was limited. As a salvage procedure for Raynaud's phenomenon recalcitrant to conservative treatment, peripheral sympathectomy improves perfusion to ischemic digits and enables amputation to be avoided.

Functional correlations of spatial quantitative EEG and intelligences in a nonalphabetical language group.

This study investigated any functional correlations between intelligences and spatially recorded quantitative electroencephalograms (QEEGs) in a nonalphabetical language group. Participants, between 6 and 8 years old, were sampled in a teaching hospital located at the central Taiwan region. The Chinese Wechsler Intelligence Scale for Children-III (WISC-III) intelligence test and quantitative electroencephalograph recording procedures were both administrated to collect data. Intelligences were divided into two categories, verbal and performance intelligences, for statistical investigations. Statistical analyses of the noncontaminated QEEG dataset investigated the differentiability of each frequency on a single cortical region and coherence between cortical regions. Low QEEG frequencies were found to have a significant correlation with intelligences on some cortical regions. Coherence between symmetric cortical regions was found to be an important factor in predicting intelligences. Results showed the feasibility of functional brain mapping in the particular language population.

Diphenylamino group as an effective handle to conjugated donor-acceptor polymers through electropolymerization.

[reaction: see text] The diphenylamino group is an effective handle for electropolymerization to give electron donor-acceptor conjugated polymers. In addition, interesting electrochromic and photoresponsive behavior of 13 has been investigated.