Development of Lead-Iodide-Based Bendable Digital Detector for Mechanical Stability Improvement of Medical Imaging Systems

Commercial flat-panel detectors (FPDs) are fragile, and they can easily be damaged when external mechanical impact is applied. To address this problem, considerable time and effort have been devoted to researching FPDs, but current studies have yet to provide solutions. In this paper, our study focused on developing a bendable digital detector for improvement of mechanically stable. We present the fabrication and measurement of the bendable X-ray detector based on PbI2; it can be fabricated via segmentation method and screen printing method. The result of experiment, detector production using the screen-printing method negatively impacts bendable properties due to porosity, which is generated due to existing moisture in the sensor layers, causing 'stress concentration' In addition, this study finds a direction relationship between porosity and electrical properties; this study demonstrates that porosity has a proportional relationship to the particle filling factor. More specifically, controlling the binder amount decreases these electrical properties. This research confirms that controlling the binder amount is an inappropriate measure for developing bendable properties and recommends further studies on the topic. Therefore, future research should focus on methods for producing polymer for improved of cross-link efficiency.11sci

High Performance Field-Effect Transistors Based on Partially Suspended 2D Materials via Block Copolymer Lithography

Although various two-dimensional (2D) materials hold great promise in next generation electronic devices, there are many challenges to overcome to be used in practical applications. One of them is the substrate effect, which directly affects the device performance. The large interfacial area and interaction between 2D materials and substrate significantly deteriorate the device performance. Several top-down approaches have been suggested to solve the problem. Unfortunately, however, they have some drawbacks such as a complicated fabrication process, a high production cost, or a poor mechanical property. Here, we suggest the partially suspended 2D materials-based field-effect transistors (FETs) by introducing block copolymer (BCP) lithography to fabricate the substrate effect-free 2D electronic devices. A wide range of nanometer size holes (diameter = 31~43 nm) is successfully realized with a BCP self-assembly nanopatterning process. With this approach, the interaction mechanism between active 2D materials and substrate is elucidated by precisely measuring the device performance at varied feature size. Our strategy can be widely applied to fabricate 2D materials-based high performance electronic, optoelectronic, and energy devices using a versatile self-assembly nanopatterning process

Challenges to the chiral magnetic wave using charge-dependent azimuthal anisotropies in pPb and PbPb collisions at sNN=\sqrt{\smash[b]{s_{_{\mathrm{NN}}}}} = 5.02 TeV

Charge-dependent anisotropy Fourier coefficients ($v_n$) of particle azimuthal distributions are measured in pPb and PbPb collisions at $\sqrt{\smash[b]{s_{_{\mathrm{NN}}}}} =$ 5.02 TeV with the CMS detector at the LHC. The normalized difference in the second-order anisotropy coefficients ($v_2$) between positively and negatively charged particles is found to depend linearly on the observed event charge asymmetry with comparable slopes for both pPb and PbPb collisions over a wide range of charged particle multiplicity. In PbPb, the third-order anisotropy coefficient, $v_3$, shows a similar linear dependence with the same slope as seen for $v_2$. The observed similarities between the $v_2$ slopes for pPb and PbPb, as well as the similar slopes for $v_2$ and $v_3$ in PbPb, are compatible with expectations based on local charge conservation in the decay of clusters or resonances, and constitute a challenge to the hypothesis that the observed charge asymmetry dependence of $v_2$ in heavy ion collisions arises from a chiral magnetic wave

Challenges to the chiral magnetic wave using charge-dependent azimuthal anisotropies in pPb and PbPb collisions at sNN= \sqrt{\smash[b]{s_{_{\mathrm{NN}}}}} = 5.02 TeV

Charge-dependent anisotropy Fourier coefficients ($v_n$) of particle azimuthal distributions are measured in pPb and PbPb collisions at $\sqrt{\smash[b]{s_{_{\mathrm{NN}}}}} =$ 5.02 TeV with the CMS detector at the LHC. The normalized difference in the second-order anisotropy coefficients ($v_2$) between positively and negatively charged particles is found to depend linearly on the observed event charge asymmetry with comparable slopes for both pPb and PbPb collisions over a wide range of charged particle multiplicity. In PbPb, the third-order anisotropy coefficient, $v_3$, shows a similar linear dependence with the same slope as seen for $v_2$. The observed similarities between the $v_2$ slopes for pPb and PbPb, as well as the similar slopes for $v_2$ and $v_3$ in PbPb, are compatible with expectations based on local charge conservation in the decay of clusters or resonances, and constitute a challenge to the hypothesis that the observed charge asymmetry dependence of $v_2$ in heavy ion collisions arises from a chiral magnetic wave