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Liquid Crystallinity as a Self-Assembly Motif for High-Efficiency, Solution-Processed, Solid-State Singlet Fission Materials

Solution and solution-deposited thin films of the discotic liquid crystalline electron acceptor–donor–acceptor (A-D-A) p-type organic semiconductor FHBC(TDPP)2, synthesized by coupling thienyl substituted diketopyrrolopyrrole (TDPP) onto a fluorenyl substituted hexa-peri-hexabenzocoronene (FHBC) core, are examined by ultrafast and nanosecond transient absorption spectroscopy, and time-resolved pho

Halide Perovskite Nanocrystals for Next-Generation Optoelectronics

Colloidal perovskite nanocrystals (PNCs) combine the outstanding optoelectronic properties of bulk perovskites with strong quantum confinement effects at the nanoscale. Their facile and low-cost synthesis, together with superior photoluminescence quantum yields and exceptional optical versatility, make PNCs promising candidates for next-generation optoelectronics. However, this field is still in i

Identifying an Optimum Perovskite Solar Cell Structure by Kinetic Analysis : Planar, Mesoporous Based, or Extremely Thin Absorber Structure

Perovskite solar cells have rapidly been developed over the past several years. Choice of the most suitable solar cell structure is crucial to improve the performance further. Here, we attempt to determine an optimum cell structure for methylammonium lead iodide (MAPbI3) perovskite sandwiched by "2 and spiro-OMeTAD layers, among planar heterojunction, mesoporous structure, and extremely thin absor

Solution-Processable, Solid State Donor–Acceptor Materials for Singlet Fission

The exploitation of singlet fission (SF) materials in optoelectronic devices is restricted by the limited number of SF materials available and developing new organic materials that undergo singlet fission is a significant challenge. Using a new strategy based on conjugating strong donor and acceptor building blocks, the small molecule (BDT(DPP)2) and polymer (p-BDT-DPP) systems are designed and sy

Excitation wavelength dependent interfacial charge transfer dynamics in a CH3NH3PbI3 perovskite film

Elucidation of interfacial charge separation and recombination mechanisms is crucial to improve performance of organic-inorganic metal halide perovskite solar cells. Here, we have investigated influence of initially populated electron and hole potential levels in a perovskite conduction band (CB) and valence band (VB), respectively, by altering an excitation wavelength on interfacial charge separa

Wafer-Scale Synthesis of Semiconducting SnO Monolayers from Interfacial Oxide Layers of Metallic Liquid Tin

Atomically thin semiconductors are one of the fastest growing categories in materials science due to their promise to enable high-performance electronic and optical devices. Furthermore, a host of intriguing phenomena have been reported to occur when a semiconductor is confined within two dimensions. However, the synthesis of large area atomically thin materials remains as a significant technologi

Fluorene-Thiophene Copolymer Wire on TiO2 : Mechanism Achieving Long Charge Separated State Lifetimes

Insertion of interfacial molecules in bulk heterojunction and dye sensitized solar cells is effective to retard charge recombination reactions and thus to improve solar cell performance. So far, to extend charge separated state lifetime, the molecule was designed to increase distance between an n-type and a p-type semiconductors to reduce their electronic coupling. Here we investigated a series of

Light intensity dependence of performance of lead halide perovskite solar cells

Performance of nanoporous TiO2 based lead iodide perovskite solar cells was investigated under a series of light intensity up to 1.2 sun. The short circuit photocurrent increases linearly with the intensity increase, while the fill factor slightly decreases with the intensity increase. The analysis of logarithmic light intensity dependence of the open circuit voltage revealed a slope of 1.09 kT/q,

Hetero Face-to-Face Porphyrin Array with Cooperative Effects of Coordination and Host–Guest Complexation

We successfully synthesized a hetero face-to-face porphyrin array composed of ZnTPP and RuTPP(DABCO)2 (TPP: 5, 10, 15, 20-tetraphenylporphyrin, DABCO: 1,4-diazabi-cyclo[2.2.2]octane) in 2:1 molar ratio. A cyclic Zn porphyrin dimer (ZnCP) was also used as the host molecule for the Ru porphyrin. In the latter, the Ru-DABCO bonding in RuTPP(DABCO)2 was stabilized by the host-guest complexation. React

Monodisperse and size-tunable PbS colloidal quantum dots via heterogeneous precursors

PbS quantum dots (QDs) are some of the most attractive QDs used to develop novel optoelectronic devices such as solar cells, photodetectors and biological labels. However, identifying an appropriate method to access high quality QDs with a wide size range employing lower cost, less toxic and safer precursors is not trivial. Here, we demonstrate the diffusion controlled synthesis of size-tunable Pb

Stable eye versus mouth preference in a live speech-processing task

Looking at the mouth region is thought to be a useful strategy for speech-perception tasks. The tendency to look at the eyes versus the mouth of another person during speech processing has thus far mainly been studied using screen-based paradigms. In this study, we estimated the eye-mouth-index (EMI) of 38 adult participants in a live setting. Participants were seated across the table from an expe

The Database of European Forest Insect and Disease Disturbances: DEFID2

Insect and disease outbreaks in forests are biotic disturbances that can profoundly alter ecosystem dynamics. In many parts of the world, these disturbance regimes are intensifying as the climate changes and shifts the distribution of species and biomes. As a result, key forest ecosystem services, such as carbon sequestration, regulation of water flows, wood production, protection of soils, and th

Family display and recognition in bonus relations

Bonus relations (such as step-grandparents, step-grandchildren, and families of choice) can be chosen, or they can be forced up on you, they can be regarded as very important to extremely peripheral. Bonus relations negotiate familiarity and can vary from inclusion to exclusion. Common to bonus-relations are their non-biological aspect: they are not blood-line relations, and to many families and fBonus relations (such as step-grandparents, step-grandchildren, and families of choice) can be chosen, or they can be forced up on you, they can be regarded as very important to extremely peripheral. Bonus relations negotiate familiarity and can vary from inclusion to exclusion. Common to bonus-relations are their non-biological aspect: they are not blood-line relations, and to many families and f

Integrating Color Deconvolution Thresholding and Weakly Supervised Learning for Automated Segmentation of Neurofibrillary Tangle and Neuropil Threads

Abnormally phosphorylated tau proteins are known to be a major indicator of Alzheimer's Disease (AD) with strong association with memory loss and cognitive decline. Automated generation of pixel-wise accurate neurofibrillary tangles (NFTs) and neuropil threads (NTs) segmentation is a challenging task, due to lack of ground truth segmentation data of these abnormal tau pathology. This problem is mo

Oxidation-induced C-H bond activation in iridium pincer complexes

Dehydrogenation reactions that produce molecular hydrogen are thermodynamically unfavourable. Desired is to couple them with a green driving force, such as oxidation with oxygen or an electric current. This, in turn, requires understanding of the catalyst's redox properties. Here we report oxidation of the iridium pincer complexes (POCOP)IrHCl (POCOP = 2,6-(tBu2PO)2C6H3; 1a) and (PCP)IrHCl (PCP =

Defunctioning stoma in anterior resection for rectal cancer does not impact anastomotic leakage : a national population-based cohort study

Background: Anterior resection (AR) is considered the gold standard for curative cancer treatment in the middle and upper rectum. The goal of the sphincter-preserving procedure, such as AR, is vulnerable to anastomotic leak (AL) complications. Defunctioning stoma (DS) became the protective measure against AL. Often a defunctioning loop-ileostomy is used, which is associated with substantial morbid