As a promising strategy for enhancing light utilization, constructing cell with tandem structure exhibits great potential in achieving high efficiency, which encourages the field of organic solar cells. Here, we develop an advanced interconnecting layer for tandem organic solar cell, which is composed of electron beam evaporated TiO x and PEDOT:PSS. By using electron beam evaporation, a sharp, smooth, and dense TiO x /PEDOT:PSS interface is obtained. By exquisite controlling the O 2 flux during evaporation, efficient electron extraction and low Schottky barrier are obtained in PBDB-TF:GS-ISO/TiO 1.76 and TiO 1.76 /PEDOT:PSS, which guarantee the charge recombination between two subcells. The tandem cell with interconnecting layer of TiO 1.76 /PEDOT:PSS shows 20.27% efficiency, which is certified as 20.0% by National Institute of Metrology, China. Therefore, our result marks the arrival of 20% era in the field of organic solar cells.

Silicon nanocrystals can provide the outstanding imaging capabilities of toxic heavy-metal-based quantum dots without employing heavy metals and have potential for rapid progression to the clinic. Understanding the toxicity of silicon quantum dots (SiQDs) is essential to realizing this potential. However, existing studies of SiQD biocompatibility are limited, with no systematic progression from small-animal to large-animal studies that are more clinically relevant. Here, we test the response of both mice and monkeys to high intravenous doses of a nanoconstruct created using only SiQDs and FDA-approved materials. We show that (1) neither mice nor monkeys show overt signs of toxicity reflected in their behavior, body mass, or blood chemistry, even at a dose of 200 mg/kg. (2) This formulation did not biodegrade as expected. Elevated levels of silicon were present in the liver and spleen of mice three months post-treatment. (3) Histopathology three months after treatment showed adverse effects of the nanoformulation in the livers of mice, but showed no such effects in monkeys. This investigation reveals that the systemic reactions of the two animal models may have some differences and there are no signs of toxicity clearly attributable to silicon quantum dots.

The development of polymerized small‐molecule acceptors has boosted the power conversion efficiencies (PCEs) of all‐polymer organic photovoltaic (OPV) cells to 17%. However, the polymer donors suitable for all‐polymer OPV cells are still lacking, restricting the further improvement of their PCEs. Herein, a new polymer donor named PQM‐Cl is designed and its photovoltaic performance is explored. The negative electrostatic potential and low average local ionization energy distribution of the PQM‐Cl surface enable efficient charge generation and transfer process. When blending with a well‐used polymer acceptor, PY‐IT, the PQM‐Cl‐based devices deliver an impressive PCE of 18.0% with a superior fill factor of 80.7%, both of which are the highest values for all‐polymer OPV cells. The relevant measurements demonstrate that PQM‐Cl‐based films possess excellent mechanical and flexible properties. As such, PQM‐Cl‐based flexible photovoltaic cells are fabricated and an excellent PCE of 16.5% with high mechanical stability is displayed. These results demonstrate that PQM‐Cl is a potential candidate for all‐polymer OPV cells and provide insights into the design of polymer donors for high‐efficient all‐polymer OPV cells.

Nasopharyngeal carcinoma (NPC) poses one of the serious health problems in southern Chinese, with an incidence rate ranging from 15 to 50/100,000. Chromosome translocation t(1;3) and frequent loss of heterogeneity on short arms of chromosome 3 and 9 have been reported to be associated with NPC, and a genome-wide scan identified an NPC susceptibility locus on chromosome 4p15.1-q12 recently. In our study, we collected samples from 18 families at high risk of NPC from the Hunan province in southern China, genotyped with a panel of polymorphic markers on short arms of chromosomes 3, 9, and 4p15.1-q12. A locus on 3p21 was identified to link to NPC with a maximum logarithm of odds for linkage score of 4.18. Fine mapping located the locus to a 13.6-cM region on 3p21.31-21.2, where a tumor suppressor gene cluster resided. Our findings identified a novel locus for NPC and provided a map location for susceptibility genes candidates. In contrast to a recent study, no significant evidence for NPC linkage to chromosomes 4 and 9 was observed.

Novel type II CdTe−CdSe semiconductor nanocrystal heterostructures (SNCHs) with multiple-branched rod morphology were synthesized by epitaxial growth of CdSe from CdTe nanocrystals in solution, and the SNCHs were characterized by transmission electron microscopy (TEM), high-resolution TEM (HRTEM), energy-dispersive spectrometry (EDS), and X-ray diffraction (XRD) analysis. The SNCHs are composed of a CdTe core and CdSe branches, and most of the heterostructured nanocrystals have about 10 branched rods with thickness of 3−5 nm and length of 10−30 nm. The absorption spectra of the SNCHs covered the whole visible region from 380 to 780 nm with a distinct peak at 560∼580 nm corresponding to the absorption of CdSe nanocrystals. The quenching of the photoluminescence (PL) peak of the CdTe core was observed in the SNCHs, which indicates that photoinduced charge separation existed in the SNCHs. Furthermore, the photovoltaic properties of the SNCHs were studied on the basis of the devices with single component of the SNCHs and with the blend of P3HT and the SNCHs. The device based on the SNCHs single component showed an open-circuit voltage (V oc) of 0.40 V, a short-circuit current density (J sc) of 0.018 mA/cm2, fill factor (FF) of 38%, and power convention efficiency (η) of 0.003% under the illumination of AM1.5, 100 mW/cm2, which is greatly improved in comparison with that of the homostructured semiconductor nanocrystals. For the hybrid P3HT/SNCHs device, the J sc, V oc, FF, and η of the device reached 0.58 mA/cm2, 0.63V, 43%, and 0.16% respectively.

This is the accepted version of the paper.This version of the publication may differ from the final published version. with an on/off ratio of 2.5 × 10 4 , which is among the best performance of the copolymers reported for the solution-processed organic field effect transistors (OFETs). The preliminary results indicate that PTZV-PT is a promising polymer material for applications in solution-processable OFETs. Permanent repository link

With the rapid advance of organic photovoltaic materials, the energy level structure, active layer morphology, and fabrication procedure of organic solar cells (OSCs) are changed significantly. Thus, the photoelectronic properties of many traditional electrode interlayers have become unsuitable for modifying new active layers; this limits the further enhancement in OSC efficiencies. Herein, a new design strategy of tailoring the end‐capping unit, ITIC, to develop a cathode interlayer (CIL) material for achieving high power conversion efficiency (PCE) in OSCs is demonstrated. The excellent electron accepting capacity, suitable energy level, and good film‐forming ability endow the S‐3 molecule with an outstanding electron extraction property. A device with S‐3 shows a PCE of 16.6%, which is among the top values in the field of OSCs. More importantly, it is demonstrated that the electrostatic potential difference between the CIL molecule and the polymer donor plays a crucial role in promoting exciton dissociation at the CIL/active layer interface, contributing to additional charge generation; this is crucial for enhancement of the current density. The results of this work not only develop a new design strategy for high‐performance CIL, but also demonstrate a reliable approach of density functional theory (DFT) calculation to predict the effect of the CIL chemical structure on exciton dissociation in OSCs.

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