We describe monocrystalline graphitic films, which are a few atoms thick but are nonetheless stable under ambient conditions, metallic, and of remarkably high quality. The films are found to be a two-dimensional semimetal with a tiny overlap between valence and conductance bands, and they exhibit a strong ambipolar electric field effect such that electrons and holes in concentrations up to 10 13 per square centimeter and with room-temperature mobilities of ∼10,000 square centimeters per volt-second can be induced by applying gate voltage.

http://science.sciencemag.org/content/sci/306/5696/666.full.pdf

Electric Field Effect in Atomically Thin Carbon Films

다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1（PfPMP1）与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用，在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员，通过启动转录不同的var基因变异体为抗原变异提供了分子基础。

疟原虫var基因转换速率变化导致抗原变异[英]／Paul H, Robert P, Christodoulou Z, et al//Proc Natl Acad Sci U S A

[신간의 별자리x] 우리/미술, 그리고 ‘슬픔의 박물관’

Many potential applications have been proposed for carbon nanotubes, including conductive and high-strength composites; energy storage and energy conversion devices; sensors; field emission displays and radiation sources; hydrogen storage media; and nanometer-sized semiconductor devices, probes, and interconnects. Some of these applications are now realized in products. Others are demonstrated in early to advanced devices, and one, hydrogen storage, is clouded by controversy. Nanotube cost, polydispersity in nanotube type, and limitations in processing and assembly methods are important barriers for some applications of single-walled nanotubes.

http://science.sciencemag.org/content/sci/297/5582/787.full.pdf

Carbon Nanotubes--the Route Toward Applications

Properties of polyparaphenylene thin films obtained by discrete evaporation in vacuum

A novel photodetecting device architecture that combines the optoelectronic property advantages of a perovskite and the amplification properties of a Si metal–oxide–semiconductor field‐effect transistor (MOSFET) to innovate a photodetecting system with ultrahigh sensitivity, especially in low‐light intensity, is demonstrated. This perovskite‐based MOSFET photodetector (PM‐PD) can respond as low as 116 nW cm−2 with extremely high responsivity 4200 A W−1. The perovskite is part of the gate dielectric to modulate the MOSFET drain current when the light intensity is changed. A direct bandgap, organic–inorganic hybrid halide perovskite with a large optical absorption coefficient, can enhance photodetector performance. However, perovskite materials are not good conductors for transporting photogenerated electrons and holes compared with single‐crystal silicon. Therefore, the perovskite was utilized as a dielectric where the capacitance is used instead. In the proposed PM‐PD architecture, changing the width‐to‐length (W/L) ratio of perovskite capacitor electrodes, can modulate the dark current from picoamperes to microamperes providing a tunable parameter for optimizing photodetecting performance. Furthermore, the capacitance of the perovskite can be modulated by frequency, which facilitates matching the capacitance of perovskite and MOSFET gate oxide—another important requirement for optimal photodetecting performance. Finally, our novel PM‐PD is commensurate with potential 3D monolithic integration.

https://onlinelibrary.wiley.com/doi/pdfdirect/10.1002/adpr.202200034

Ultrasensitive Perovskite Photodetector Achieved When Configured with a Si Metal Oxide Semiconductor Field‐Effect Transistor

Solution‐processed organic–inorganic metal halide perovskites have recently attracted tremendous attention in the photodetector community due to their excellent optoelectronic properties and facile fabrication. The main challenge in perovskite photodetectors (PSPDs) is to achieve high responsivity and fast speed simultaneously. In this work, this challenge is overcome by employing a directly patterned nanograting methylammonium lead iodide (MAPbI3) film in metal‐semiconductor‐metal (MSM) PSPD on interdigitated indium tin oxide (ITO) electrodes. Because of the improved perovskite morphology after directly patterning by nanoimprint lithography, as well as the enhanced electric field intensity by the perovskite nanograting and interdigitated electrodes, the PSPDs have responsivity of 441 A W−1, detectivity of 8.32 × 1012 Jones, response time of 10.7 µs, all of which are among the best performances in MSM PSPDs. Moreover, the PSPDs maintain excellent photocurrent performance after 20 days of air exposure. The approach opens a path to manufacturing‐friendly, high‐performance, and reliable PSPDs and paves the way toward perovskite‐based optoelectronic circuits.

https://onlinelibrary.wiley.com/doi/pdfdirect/10.1002/adom.202201516

High‐Performance Directly Patterned Nanograting Perovskite Photodetector with Interdigitated Electrodes

Hybrid halide perovskite has made great advances for making new composition of materials, which have wide usage in advanced optoelectronic devices. Here we show amplified spontaneous emission (ASE) in a perovskite nanograting metasurface, defined by the cost effective nanoimprint lithography method which cannot typically be applied to hard, ionic based materials such as perovskite.

Amplified spontaneous emission in nanoimprinted perovskite nanograting metasurface

Organic-inorganic perovskite light-emitting devices have recently emerged as a reliable light source. Here, we developed a Single Layer Perovskite Light-Emitting Electrochemical Cells (SL-PeLEC) with laminated free-standing Carbon Nanotube Sheet (CNT) sheets as an effective charge electron injecting cathode electrode. The structure consists of bottom ITO-on-glass as a transparent electrode, the composite of CsPbBr3:PEO:LiPF6 with additive ionic salt as an emitting layer (EML) and 5 layers of CNT aerogel sheets as a top laminated cathode . Utilizing CNT free standing sheets laminated right on top of perovskite thin film in this simple single layer configuration has multiple benefits. Such CNT top cathode does not show any chemical degradation by reaction with halogens from perovskite, which is detrimental for metallic cathodes. Moreover, the formation of an internal p-i-n junction in perovskite EML composite layer by ionic migration under applied voltage bias and electric double layer (EDL) formation at each electrode interface is beneficially effecting CNT sheets by Li+ ionic doping and raises their Fermi level, further enhancing electron injection. Besides, inspired by successes of ionic additives in LECs and electrochemical doping of perovskite with alkali metals, we leveraged a lithium salt, LiPF6, within a CsPbBr3:PEO composite matrix to achieve optimal ionic redistribution and doping effects in this SL-PeLEC. Although initially CNT electrode has slightly high sheet resistance, the SL-PeLEC device has a low turn-on voltage of 2.6v and a maximum luminance intensity of 530 cd/m2, confirming the n-doping increased conductivity. This work provides a unique route toward flexible and bright perovskite LECs with stable and transparent CNT electrodes that can have injection efficiency tuned by poling induced ionic EDL-doping

Anvar A. Zakhidov

Papers

Properties of polyparaphenylene thin films obtained by discrete evaporation in vacuum

Ultrasensitive Perovskite Photodetector Achieved When Configured with a Si Metal Oxide Semiconductor Field‐Effect Transistor

High‐Performance Directly Patterned Nanograting Perovskite Photodetector with Interdigitated Electrodes

Amplified spontaneous emission in nanoimprinted perovskite nanograting metasurface

Bright perovskite light-emitting electrochemical cell utilizing CNT sheets as a tunable charge injector