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

http://manuscript.elsevier.com/S2211285521011563/pdf/S2211285521011563.pdf

Bulk heterojunction perovskite solar cells incorporated with p-type low optical gap conjugated polymers

Further correction for ‘Low bandgap semiconducting polymers for polymeric photovoltaics’ by Chang Liu et al., Chem. Soc. Rev., 2016, DOI: 10.1039/c5cs00650c.

/pdf/further-correction-low-bandgap-semiconducting-polymers-for-31xsql7ksq.pdf

Further correction: Low bandgap semiconducting polymers for polymeric photovoltaics

New pyrochlore-type rare-earth-complex oxides of nanometer size and with B-site dopants, RE2Sn2−xB′xO7 (RE = Sm, Ce; B′= Fe, Co, Ni; 0.0 ≤ x ≤ 1.0), have been prepared by the nonalcoholate sol-gel method. The range of average particle size is from 25 to 30 nm. It is found that this method can lower the reaction temperature (about 500 K) and shorten the reaction time. The crystal structures of these nanocrystallites belong to the cubic system, and their lattice parameters are linearly related to the content of the dopant ions. The IR spectra of these nanocrystallites were investigated, and the excitation and emission spectra for these systems show that the luminescent intensities of RE3+ become weaker with the iron-group dopant in the order of Fe, Co, and Ni.

Preparation and optical properties of nanocrystallites of re2sn2-xb'xo7 (re = sm, ce; b' = fe, co, ni; 0.0 x 1.0)

http://manuscript.elsevier.com/S2211285522002075/pdf/S2211285522002075.pdf

Stable and Efficient Perovskite Solar Cells by Discrete Two-dimensional Perovskites Capped on the Three-dimensional Perovskites Bilayer Thin Film

Perovskite solar cells (PSCs) have emerged as a cost-effective solar technology in the past years. PSCs by three-dimensional hybrid inorganic-organic perovskites exhibited decent power conversion efficiencies (PCEs); however, their stabilities were poor. On the other hand, PSCs by all-inorganic perovskites indeed exhibited good stability, but their PCEs were low. Here, the development of novel all-inorganic perovskites CsPbI2Br:xNd3+, where Pb2+ at the B-site is partially heterovalently substituted by Nd3+, is reported. The CsPbI2Br:xNd3+ thin films possess enlarged crystal sizes, enhanced charge carrier mobilities, and superior crystallinity. Thus, the PSCs by the CsPbI2Br:xNd3+ thin films exhibit more than 20% enhanced PCEs and dramatically boosted stability compared to those based on pristine CsPbI2Br thin films. To further boost the device performance of PSCs, solution-processed 4-lithium styrenesulfonic acid/styrene copolymer (LiSPS) is utilized to passivate the surface defect and suppress surface charge carrier recombination. The PSCs based on the CsPbI2Br:xNd3+/LiSPS bilayer thin film possess reduced charge extraction lifetime and suppressed charge carrier recombination, resulting in 14% enhanced PCEs and significantly boosted stability compared to those without incorporation of the LiSPS interface passivation layer. All these results indicate that we developed a facile way to approach high-performance PSCs by all-inorganic perovskites.

Xiong Gong

Papers

Bulk heterojunction perovskite solar cells incorporated with p-type low optical gap conjugated polymers

Further correction: Low bandgap semiconducting polymers for polymeric photovoltaics

Preparation and optical properties of nanocrystallites of re2sn2-xb'xo7 (re = sm, ce; b' = fe, co, ni; 0.0 x 1.0)

Stable and Efficient Perovskite Solar Cells by Discrete Two-dimensional Perovskites Capped on the Three-dimensional Perovskites Bilayer Thin Film

Efficient and Stable Perovskite Solar Cells by B-Site Compositional Engineered All-Inorganic Perovskites and Interface Passivation.