56 research outputs found
Ultra-Short Pulsed Laser Annealing Effects on MoS2 Transistors with Asymmetric and Symmetric Contacts
The ultra-short pulsed laser annealing process enhances the performance of MoS 2 thin film transistors (TFTs) without thermal damage on plastic substrates. However, there has been insufficient investigation into how much improvement can be brought about by the laser process. In this paper, we observed how the parameters of TFTs, i.e., mobility, subthreshold swing, I on /I off ratio, and V th , changed as the TFTs’ contacts were (1) not annealed, (2) annealed on one side, or (3) annealed on both sides. The results showed that the linear effective mobility (µeff_lin) increased from 13.14 [cm 2 /Vs] (not annealed) to 18.84 (one side annealed) to 24.91 (both sides annealed). Also, I on /I off ratio increased from 2.27 x 10 5 (not annealed) to 3.14 x 10 5 (one side annealed) to 4.81 x 10 5 (both sides annealed), with V th shifting to negative direction. Analyzing the main reason for the improvement through the Y function method (YFM), we found that both the contact resistance (R c ) and the channel interface resistance (R ch ) improves after the pulsed laser annealings under different conditions. Moreover, the Rc enhances more dramatically than the R ch does. In conclusion, our picosecond laser annealing improves the performance of TFTs (especially, the R c ) in direct proportion to the number of annealings applied. The results will contribute to the investigation about correlations between the laser annealing process and the performance of devices. © 2019 by the authors. Licensee MDPI, Basel, Switzerland.1
Conformal and Ultra Shallow Junction Formation Achieved Using a Pulsed-Laser Annealing Process Integrated With a Modified Plasma Assisted Doping Method
Recently, a shallow and conformal doping profile is required for promising 3D structured devices. In this study, we deposited the dopant phosphorus (P) using modified plasma assisted doping (PaD) followed by an annealing process to electrically activate the dopants. A rapid thermal annealing process (RTP) was the first approach tested for activation but it resulted in a deep junction ( > 35 nm). To reduce the junction depth, we tried the fiash lamp annealing process (FLP) to shorten the annealing time. We also predicted the annealing temperature by numerical thermal analysis, which reached 1,020 degrees C. However, the FLP resulted in a deep junction (similar to 30 nm), which was not shallow enough to suppress short channel effects. Since an even shorter annealing process was required to form a ultra-shallow junction, we tried the laser annealing process (LAP) as a promising alternative. The LAP, which had a power density of 0.3 J/cm(2), increased the surface temperature up to 1,100 degrees C with a shallow isothermal layer. Using the LAP, we achieved a USJ with an activated surface dopant concentration of 3.86 x 10(19) cm(-3) and a junction depth of 10 nm, which will allow further scaling-down of devices.1
Moxifloxacin: Clinically compatible contrast agent for multiphoton imaging
Multiphoton microscopy (MPM) is a nonlinear fluorescence microscopic technique widely used for cellular imaging of thick tissues and live animals in biological studies. However, MPM application to human tissues is limited by weak endogenous fluorescence in tissue and cytotoxicity of exogenous probes. Herein, we describe the applications of moxifloxacin, an FDA-approved antibiotic, as a cell-labeling agent for MPM. Moxifloxacin has bright intrinsic multiphoton fluorescence, good tissue penetration and high intracellular concentration. MPM with moxifloxacin was demonstrated in various cell lines, and animal tissues of cornea, skin, small intestine and bladder. Clinical application is promising since imaging based on moxifloxacin labeling could be 10 times faster than imaging based on endogenous fluorescence.David H. Koch Institute for Integrative Cancer Research at MIT (Bridge Initiative
An analysis of the civilianization of the Ministry of National Defense in the Republic of Korea in support of Defense Reform 2020
The purpose of this study is to investigate the feasibility of the civilianization plan of the Ministry of National Defense (MND) in the Republic of Korea (ROK). MND developed a plan to construct modernized military power and to operate it efficiently and effectively. MND promotes the plan to increase civilian personnel ratio inside the Headquarters by 2009, which is relatively faster than other main policies. Moreover, the environment inside and outside the organization is not mature enough to drive this policy quickly. There are also widely differing points of view on this policy between military members and civilian personnel. Defense ministries in other countries, especially the United States, have well-developed systems to educate and recruit civilian experts. By doing so, they attained a high level of civilian participation while minimizing possible problems. Many people in the organization worry about this plan because there are not enough organizations and systems to educate and train civilian defense experts. Although the direct comparison of workforce capability between military members and civilian personnel is limited, there are advantages and disadvantages that can be obtained through civilianization. Therefore, it is necessary to change this policy to a long-term one with more elaborate procedures.http://archive.org/details/annalysisofcivil109454926Republic of Korea Army author.Approved for public release; distribution is unlimited
Moxifloxacin based two-photon imaging of human skin cancer, ex-vivo
In skin cancer surgery, the rapid and accurate detection of surgical margin is required for precise and complete removal. Reflectance confocal microscopy (RCM) is currently used to guide the surgical margin, but has a limited detection contrast. In this study, we used a moxifloxacin based two-photon microscopy (moxi-TPM) as a high-speed and high-contrast method of human skin cancer. High-speed TPM was realized by using moxifloxacin as a cell-labeling agent. Various skin cancer tissues including squamous cell carcinoma, basal cell carcinoma, and highly pigmented melanoma were visualized in cellular level resolution by using moxi-TPM, and these moxi-TPM images were compared with dermoscopic images and histology. These results showed that moxi-TPM could be used for guiding skin cancer surgery owing to its high imaging speed and resolution.2
Directional neurite growth using carbon nanotube patterned substrates as a biomimetic cue
Researchers have made extensive efforts to mimic or reverse-engineer in vivo neural circuits using micropatterning technology. Various surface chemical cues or topographical structures have been proposed to design neuronal networks in vitro. In this paper, we propose a carbon nanotube (CNT)-based network engineering method which naturally mimics the structure of extracellular matrix (ECM). On CNT patterned substrates, poly-L-lysine (PLL) was coated, and E18 rat hippocampal neurons were cultured. In the early developmental stage, soma adhesion and neurite extension occurred in disregard of the surface CNT patterns. However, later the majority of neurites selectively grew along CNT patterns and extended further than other neurites that originally did not follow the patterns. Long-term cultured neuronal networks had a strong resemblance to the in vivo neural circuit structures. The selective guidance is possibly attributed to higher PLL adsorption on CNT patterns and the nanomesh structure of the CNT patterns. The results showed that CNT patterned substrates can be used as novel neuronal patterning substrates for in vitro neural engineering
Optical property dataset of inorganic phosphor
Abstract Developing inorganic phosphor with desired properties for light-emitting diode application has traditionally relied on time-consuming and labor-intensive material development processes. Moreover, the results of material development research depend significantly on individual researchers’ intuition and experience. Thus, to improve the efficiency and reliability of materials discovery, machine learning has been widely applied to various materials science applications in recent years. However, the prediction capabilities of machine learning methods fundamentally depend on the quality of the training datasets. In this work, we constructed a high-quality and reliable dataset that contains experimentally validated inorganic phosphors and their optical properties, sourced from the literature on inorganic phosphors. Our dataset includes 3952 combinations of 21 dopant elements in 2238 host materials from 553 articles. The dataset provides material information, optical properties, measurement conditions for inorganic phosphors, and meta-information. Among the preliminary machine learning results, the essential properties of inorganic phosphors, such as maximum Photoluminescence (PL) emission wavelength and PL decay time, show overall satisfactory prediction performance with coefficient of determination ( R 2 ) scores of 0.7 or more. We also confirmed that the measurement conditions significantly improved prediction performance
- …