There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

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

The need to develop inexpensive renewable energy sources stimulates scientific research for efficient, low-cost photovoltaic devices.1 The organic, polymer-based photovoltaic elements have introduced at least the potential of obtaining cheap and easy methods to produce energy from light.2 The possibility of chemically manipulating the material properties of polymers (plastics) combined with a variety of easy and cheap processing techniques has made polymer-based materials present in almost every aspect of modern society.3 Organic semiconductors have several advantages: (a) lowcost synthesis, and (b) easy manufacture of thin film devices by vacuum evaporation/sublimation or solution cast or printing technologies. Furthermore, organic semiconductor thin films may show high absorption coefficients4 exceeding 105 cm-1, which makes them good chromophores for optoelectronic applications. The electronic band gap of organic semiconductors can be engineered by chemical synthesis for simple color changing of light emitting diodes (LEDs).5 Charge carrier mobilities as high as 10 cm2/V‚s6 made them competitive with amorphous silicon.7 This review is organized as follows. In the first part, we will give a general introduction to the materials, production techniques, working principles, critical parameters, and stability of the organic solar cells. In the second part, we will focus on conjugated polymer/fullerene bulk heterojunction solar cells, mainly on polyphenylenevinylene (PPV) derivatives/(1-(3-methoxycarbonyl) propyl-1-phenyl[6,6]C61) (PCBM) fullerene derivatives and poly(3-hexylthiophene) (P3HT)/PCBM systems. In the third part, we will discuss the alternative approaches such as polymer/polymer solar cells and organic/inorganic hybrid solar cells. In the fourth part, we will suggest possible routes for further improvements and finish with some conclusions. The different papers mentioned in the text have been chosen for didactical purposes and cannot reflect the chronology of the research field nor have a claim of completeness. The further interested reader is referred to the vast amount of quality papers published in this field during the past decade.

Conjugated polymer-based organic solar cells

A polymer solar-cell based on a bulk hetereojunction design with an internal quantum efficiency of over 90% across the visible spectrum (425 nm to 575 nm) is reported. The device exhibits a power-conversion efficiency of 6% under standard air-mass 1.5 global illumination tests.

Bulk heterojunction solar cells with internal quantum efficiency approaching 100

Fossil fuel alternatives, such as solar energy, are moving to the forefront in a variety of research fields. Polymer-based organic photovoltaic systems hold the promise for a cost-effective, lightweight solar energy conversion platform, which could benefit from simple solution processing of the active layer. The function of such excitonic solar cells is based on photoinduced electron transfer from a donor to an acceptor. Fullerenes have become the ubiquitous acceptors because of their high electron affinity and ability to transport charge effectively. The most effective solar cells have been made from bicontinuous polymer–fullerene composites, or so-called bulk heterojunctions. The best solar cells currently achieve an efficiency of about 5 %, thus significant advances in the fundamental understanding of the complex interplay between the active layer morphology and electronic properties are required if this technology is to find viable application.

Polymer–Fullerene Composite Solar Cells

Metal halide perovskite solar cells (PSCs) attract an enormous attention because of their high power conversion efficiency (PCE) and low fabrication cost. However, their commercialization is limited by fabricating highly efficient large‐area solar cells. Controlling the morphology and crystallization of perovskite for large‐area fabrication is difficult but important. Herein, a vacuum‐assisted approach is developed to obtain mirror‐like, pinhole‐free, highly crystalline, and uniform blade‐coated perovskite films, without the use of antisolvent and air knife. This method can be a universal approach for various perovskite compositions. Meanwhile, the phenethylammonium iodide passivation effect at the top and bottom interfaces of perovskite layer based on FTO/NiOx/perovskite/C60/BCP/Cu inverted p‐i‐n structure is systematically investigated. The optimized device fabricated by blade coating under an ambient environment exhibits the champion PCE of 20.7% and is among the top few records of blade coating inverted structure based on NiOx hole transport layer. The encapsulated device retains 97% of its maximum efficiency under open‐circuit condition after 1000 h of photostability test in an ambient environment at room temperature with a relative humidity of 40–60%. Herein, low‐cost, easy, and reproducible strategies to fabricate efficient and stable blade‐coated PSCs are demonstrated.

Blade Coating Inverted Perovskite Solar Cells with Vacuum‐Assisted Nucleation Based on Bottom Quasi‐2D Passivation

Polymer white light-emitting diodes

L'invention concerne des diodes electroluminescentes polymeres electrophosphorescentes (PLED) emettant de la lumiere blanche au moyen de polymeres semi-conducteurs melanges a des emetteurs organometalliques comme materiaux emissifs dans une zone commune. Ces materiaux peuvent etre coules d'une solution. Les coordonnees CIE, les temperatures de couleur et les indices de rendu de couleurs de l'emission blanche sont insensibles a la brillance, a la tension appliquee et a la densite du courant applique.

Electrophosphorescence blanche de melanges polymeres semi-conducteurs

Verfahren zum Ausbilden benachbarter Schichten aus Materialien auf einem Substrat umfassend: A method of forming adjacent layers of materials on a substrate comprising: Bereitstellen einer ersten Losung, die ein erstes Material, das ein wasserlosliches, kationisches, konjugiertes Polymer ist, und ein erstes Losungsmittel umfasst; Providing a first solution comprising a first material which is a water soluble cationic conjugated polymer, and a first solvent; Bereitstellen einer zweiten Losung, die ein zweites Material umfassend ein emittierendes, halbleitendes Polymer und ein zweites Losungsmittel umfasst; Providing a second solution comprising a second material comprises an emissive semiconducting polymer and a second solvent; Abscheiden einer ersten Schicht einer der ersten und zweiten Losungen auf ein Substrat; Depositing a first layer of one of the first and second solutions to a substrate; Abscheiden einer zweiten Schicht der anderen der ersten und zweiten Losungen auf der ersten Schicht; Depositing a second layer of the other of the first and second solutions on the first layer; Wobei: das Material, das in der ersten Schicht abgeschieden wurde, sich nicht in dem Losungsmittel, das in der zweiten Schicht abgeschieden wurde, lost; Wherein: said material which has been deposited in the first layer, not in the solvent which has been deposited in the second layer, dissolves; und and das wasserlosliche, kationische, konjugierte Polymer ein hochstes besetztes Molekulorbital, HOMO, bei einer Energie nahe oder innerhalb des Valenzbandes des emittierenden, halbleitenden Polymers hat, oder das wasserlosliche, kationische, konjugierte Polymer ein tiefstes, nicht besetztes Molekulorbital, LUMO, bei einer Energie nahe oder innerhalb des Leitungsbandes des emittierenden, halbleitenden Polymers hat. the water-soluble cationic conjugated polymer is a highest occupied molecular orbital, HOMO, has at an energy close to or within the valence band of the emissive semiconducting polymer, or the water-soluble cationic conjugated polymer is a deepest, not occupied molecular orbital, LUMO, next to a power or has within the conduction band of the emissive semiconducting polymer.

Verfahren umfassend lösliche, konjugierte Polymere zur Ausbildung benachbarter Schichten auf einem Substrat oder zum Hinzufügen einer Polymerschicht zu einem Substrat, mehrschichtige elektronische Vorrichtung und Verwendung in elektronischen Bauteilen A method comprising soluble conjugated polymers to form adjacent layers on a substrate or for adding a polymer layer to a substrate, multilayer electronic device and use in electronic components

The photocurrent multiplication (PM) effect has been used to boost the device performance of polymer-based photodetectors (PDs), but its origin was rarely addressed. In this study, we report the origins of the PM effect in polymer PDs based on the P3HT:PC71 BM bulk heterojunction (BHJ) composite thin film, where P3HT is poly(3-hexylthiophene), and PC71 BM is [6,6]phenyl-C71 -butyric acid methyl ester, through both computational simulation and experimental investigation. Systematically studies indicate that two key factors play an important role in the realization of the PM effect in polymer PDs. One factor is the work function of the metal electrode, and another is the PC71 BM aggregations at the interface between the P3HT:PC71 BM BHJ composite thin film and the metal electrode. Moreover, the results from both experimental and computational simulation indicate that the values of the current density under the light illumination minus the current density in the dark of polymer PDs are increased simultaneously along with the reduction of the thickness of the P3HT:PC71 BM BHJ composite thin film. Our results provide an understanding of the PM effect in polymer PDs and the guidance for the development of high-performance polymer PDs based on BHJ composite thin film. This article is protected by copyright. All rights reserved.

https://rss.onlinelibrary.wiley.com/doi/am-pdf/10.1002/marc.202100928

Xiong Gong

Papers

Blade Coating Inverted Perovskite Solar Cells with Vacuum‐Assisted Nucleation Based on Bottom Quasi‐2D Passivation

Polymer white light-emitting diodes

Electrophosphorescence blanche de melanges polymeres semi-conducteurs

Origins of the Photocurrent Multiplication Effect in the Polythiophene-based Photodetectors.