Nanoscale Phase Change Material Array by Sub-Resolution Assist Feature for Storage Class Memory Application.

High density phase change memory array requires both minimized critical dimension (CD) and maximized process window for the phase change material layer. High in-wafer uniformity of the nanoscale patterning of chalcogenides material is challenging given the optical proximity effect (OPE) in the lithography process and the micro-loading effect in the etching process. In this study, we demonstrate an approach to fabricate high density phase change material arrays with half-pitch down to around 70 nm by the co-optimization of lithography and plasma etching process. The focused-energy matrix was performed to improve the pattern process window of phase change material on a 12-inch wafer. A variety of patternings from an isolated line to a dense pitch line were investigated using immersion lithography system. The collapse of the edge line is observed due to the OPE induced shrinkage in linewidth, which is deteriorative as the patterning density increases. The sub-resolution assist feature (SRAF) was placed to increase the width of the lines at both edges of each patterning by taking advantage of the optical interference between the main features and the assistant features. The survival of the line at the edges is confirmed with around a 70 nm half-pitch feature in various arrays. A uniform etching profile across the pitch line pattern of phase change material was demonstrated in which the micro-loading effect and the plasma etching damage were significantly suppressed by co-optimizing the etching parameters. The results pave the way to achieve high density device arrays with improved uniformity and reliability for mass storage applications.

Polyoxometalates acting as a hole-transfer mediator and crystallization accelerant in a perovskite photoanode for the photoelectrocatalytic oxidation of benzene into phenol.

Organic metal halide perovskite (OMHP) material shows promising applications in the photoelectrocatalytic field, but its efficiencies are unsatisfactory due to the bulk and surface carrier recombination. In this work, we used dual polyoxometalates (C4H9N)3PW12O40 and [Ag10[{Co(H2O)3}2{CoBi2W19O66(OH)4}] to modify the OMHP photoanode; the former acted to improve the quality of the perovskite film and the latter could facilitate hole transfer. Such dual modifications effectively reduce carrier recombination and thus obviously boost photoelectrocatalytic efficiency. Hence, we explored the photoelectrocatalytic oxidation of benzene into phenol in aqueous solution by using the modified OMHP photoanode. The yield of phenol in the reaction using the modified OMHP photoanode reached about 31.8%, which was obviously superior to that using the pure OMHP photoanode. Furthermore, we carried out radical scavenger studies to investigate the active species involved in the photoelectrocatalytic benzene oxidation reaction, and thus proposed the plausible mechanism of the photoelectrocatalytic oxidation of benzene into phenol over the OMHP photoanode. These results provide new insights into the development of high performance OMHP photoanodes for photoelectrocatalytic organic transformation.

SIK2 Promotes Cisplatin Resistance Induced by Aerobic Glycolysis in Breast Cancer Cells through PI3K/AKT/mTOR Signaling Pathway.

This study aimed to investigate the effect of SIK2 on cisplatin resistance induced by aerobic glycolysis in breast cancer cells and its potential mechanism. qRt-PCR and Western blot were used to detect SIK2 mRNA and protein levels, and cisplatin (DDP) resistant cell lines of breast cancer cells were established. Viability was measured and evaluated via CCK-8, cell invasion capability was evaluated via Transwell, and apoptosis rate was assessed via Flow cytometry. The glycolysis level was evaluated by measuring glucose consumption and lactic acid production. The protein levels of p-PI3K, p- protein kinase B (Akt) and p-mTOR were determined by western blot. SIK2 was highly expressed in breast cancer tissues and cells compared with adjacent tissues and normal human breast epithelial cells, and it had higher diagnostic value for breast cancer. Silencing SIK2 expression can inhibit proliferation and invasion of breast cancer cells and induce their apoptosis. In addition, SIK2 knockdown inhibits glycolysis, reverses the resistance of drug-resistant cells to cisplatin, and inhibits PI3K/AKT/mTOR signaling pathway. When LY294002 was used to inhibit PI3K/AKT/mTOR signaling pathway, the effect of pcDNA3.1-SIK2 on aerobic glycolysis of breast cancer cells could be reversed. SIK2 can promote cisplatin resistance caused by aerobic glycolysis of breast cancer cells through PI3K/AKT/mTOR signaling pathway, which may be a new target to improve cisplatin resistance of breast cancer cells.

A visible-light-responsive TaON/CdS photocatalytic film with a ZnS passivation layer for highly extraordinary NO2 photodegradation.

Recently, TaON has become a promising photoelectrode material in the photocatalytic field owing to its suitable band gap and superior charge carrier transfer ability. In this work, we prepared a TaON/CdS photocatalytic film using a CdS nanoparticle-modified TaON film by the successive ionic layer adsorption and reaction (SILAR) method. For the first time, the ZnS nanoparticles were deposited on the TaON/CdS film using the same method. We found that pure TaON had a nanoporous morphology, thus resulting in high specific surface area and better gas adsorption capacity. Furthermore, the TaON/CdS/ZnS film displayed a highly efficient NO2 photodegradation rate under visible light irradiation owing to its stronger visible light response, photocorrosion preventive capacity, and the high separation efficiency of photo-induced electrons and holes. Interestingly, the promising TaON/CdS/ZnS film also possessed remarkable recyclability for NO2 degradation. Therefore, we suggest that the TaON/CdS/ZnS photocatalytic film might be used for the photocatalytic degradation of other pollutants or in other applications. We also put forward the feasible NO2 photocatalytic degradation mechanism for the TaON/CdS/ZnS film. From the schematic diagram, we could further obtain the photo-generated carrier transport process and NO2 photodegradation principle in detail over the ternary photocatalytic film. Moreover, the trapping experiment demonstrates that ·O2 - and h+ all play significant roles in NO2 degradation under visible light irradiation.

Dual modification of TiO2 nanorod arrays with SiW11Co and Ag nanoparticles for enhanced photocatalytic activity under simulated sunlight.

Well-organized TiO2 nanorod arrays (TNRs) have increasingly attracted our attention in recent years due to their excellent photocatalytic properties. However, it is of great importance to prepare more efficient photocatalysts using a facile method towards their more widespread use. In this work, K6SiW11O39Co(ii)(H2O) (SiW11Co) and Ag nanoparticles were introduced into TNRs using spin-coating and chemical bath deposition methods. It was found that TNRs/SiW11Co/Ag composite films with an active area of only 1 cm2 exhibit highly efficient and sustainable properties for the photodegradation of NO2 and display a significant enhancement compared with P25 and pure TNRs. Photocatalytic measurements demonstrated that both SiW11Co and Ag synergistically improve the light absorption and charge separation efficiency, thus obtaining the most efficient photocatalytic performance. In addition, the probable photocatalytic mechanism and the dominating active species for NO2 photodegradation were also proposed, in order to testify the effectively enhanced photocatalytic ability of the TNRs/SiW11Co/Ag composite. Hence, the design of these polyoxometalate and metal particle co-modified TNRs may provide a new tactic for developing promising materials for photocatalytic degradation.

A layered titanium(iv)-peroxo-pyridine dicarboxylic cluster: crystal structure and photoelectrochemical sensing of dopamine.

A layered titanium(iv)-peroxo-pyridine dicarboxylic cluster K9[Ti3O4(O2)3(C7H3O4N)3(OH2)2]Cl·4H2O 1 has been synthesized by the H2O2-assisted reaction between TiCl4 and dipicolinic acid ligands. The semiconducting properties of this solid state compound were revealed from measurements of the diffuse reflectance UV-vis spectra and photocurrent response. Its photoelectrochemical sensing of dopamine was also investigated.

Experimental demonstration of longitudinal beam phase-space linearizer in a free-electron laser facility by corrugated structures.

Removal of the undesired time-energy correlations in the electron beam is of paramount importance for efficient lasing of a high-gain free-electron laser. Recently, it has been theoretically and experimentally demonstrated that the longitudinal wakefield excited by the electrons themselves in a corrugated structure allows for precise control of the electron beam phase space. In this Letter, we report the first utilization of a corrugated structure as a beam linearizer in the operation of a seeded free-electron laser driven by a 140 MeV linear accelerator, where a gain of ∼10 000 over spontaneous emission was achieved at the second harmonic of the 1047 nm seed laser, and a free-electron laser bandwidth narrowing by 50% was observed, in good agreement with the theoretical expectations.