Efficient and stable noble-metal-free catalyst for acidic water oxidation.

Developing non-noble catalysts with superior activity and durability for oxygen evolution reaction (OER) in acidic media is paramount for hydrogen production from water. Still, challenges remain due to the inadequate activity and stability of the OER catalyst. Here, we report a cost-effective and stable manganese oxybromide (MnOBr) catalyst exhibiting an excellent OER activity in acidic electrolytes, with an overpotential of as low as 295 ± 5 mV at a current density of 10 mA cm.

Efficient and Stable Perovskite Solar Cell Achieved with Bifunctional Interfacial Layers.

The elaborate control of the surface morphologies and trap states of solution-processed perovskite films significantly governs the photovoltaic performance and moisture resistance of perovskite solar cells (PSCs). Herein, a thin layer of poly(triaryl amine) (PTAA) was unprecedentedly devised on top of perovskite quasi-film by spin-coating PTAA/chlorobenzene solution before annealing the perovskite film. This treatment induced a smooth and compact perovskite layer with passivated surface defects and grain boundaries, which result in a significantly reduced charge recombination.

Hydrogenated TiO Thin Film for Accelerating Electron Transport in Highly Efficient Planar Perovskite Solar Cells.

Intensive studies on low-temperature deposited electron transport materials have been performed to improve the efficiency of n-i-p type planar perovskite solar cells to extend their application on plastic and multijunction device architectures. Here, a TiO film with enhanced conductivity and tailored band edge is prepared by magnetron sputtering at room temperature by hydrogen doping (HTO), which accelerates the electron extraction from perovskite photoabsorber and reduces charge transfer resistance, resulting in an improved short circuit current density and fill factor. The HTO film with upward shifted Fermi level guarantees a smaller loss on and facilitates the growth of high-quality absorber with much larger grains and more uniform size, leading to devices with negligible hysteresis.

Origin of Photovoltage Enhancement via Interfacial Modification with Silver Nanoparticles Embedded in an a-SiC:H p-Type Layer in a-Si:H Solar Cells.

We used silver nanoparticles (Ag-NPs) embedded in the p-type semiconductor layer of hydrogenated amorphous silicon (a-Si:H) solar cells in the Schottky barrier contact design to modify the interface between aluminum-doped ZnO (ZnO:Al, AZO) and p-type hydrogenated amorphous silicon carbide (p-a-SiC:H) without plasmonic absorption. The high work function of the Ag-NPs provided a good channel for the transport of photogenerated holes. A p-type nanocrystalline SiC:H layer was used to compensate for the real surface defects and voids on the surface of Ag-NPs to reduce recombination at the AZO/p-type layer interface, which then enhanced the photovoltage of single-junction a-Si:H solar cells to values as high as 1.

Compound Homojunction:Heterojunction Reduces Bulk and Interface Recombination in ZnO Photoanodes for Water Splitting.

Photoelectrochemical water splitting is far more efficient thanks to the novel ZnOSe/ZnO/BZO thin-film photoanodes fabricated in this work. A novel structure is developed for simultaneously suppressing the charge recombination in the ZnO bulk and at the semiconductor-electrolyte interface. This structure achieves a five-fold enhancement in water-splitting performance, compared to that of pristine ZnO photoanodes, when illuminated using visible light.

Role of hydrogen plasma pretreatment in improving passivation of the silicon surface for solar cells applications.

We have investigated the role of hydrogen plasma pretreatment in promoting silicon surface passivation, in particular examining its effects on modifying the microstructure of the subsequently deposited thin hydrogenated amorphous silicon (a-Si:H) passivation film. We demonstrate that pretreating the silicon surface with hydrogen plasma for 40 s improves the homogeneity and compactness of the a-Si:H film by enhancing precursor diffusion and thus increasing the minority carrier lifetime (τ(eff)). However, excessive pretreatment also increases the density of dangling bond defects on the surface due to etching effects of the hydrogen plasma.

Improved amorphous/crystalline silicon interface passivation for heterojunction solar cells by low-temperature chemical vapor deposition and post-annealing treatment.

In this study, hydrogenated amorphous silicon (a-Si:H) thin films are deposited using a radio-frequency plasma-enhanced chemical vapor deposition (RF-PECVD) system. The Si-H configuration of the a-Si:H/c-Si interface is regulated by optimizing the deposition temperature and post-annealing duration to improve the minority carrier lifetime (τeff) of a commercial Czochralski (Cz) silicon wafer. The mechanism of this improvement involves saturation of the microstructural defects with hydrogen evolved within the a-Si:H films due to the transformation from SiH2 into SiH during the annealing process.

[Arterial blood gas and electrolytes in severe pulmonary tuberculosis with respiratory failure: analysis of 50 cases].

Objective: To study the characteristics of arterial blood gas and electrolytes in patients with severe pulmonary tuberculosis with respiratory failure.

Method: In 50 patients with severe pulmonary tuberculosis, the arterial blood gas and electrolytes were measured after the onset of respiratory failure to define the types of respiratory failure and acid-base imbalance.

Results: Severe pulmonary tuberculosis with respiratory failure was characterized by development of hypoxia, and the degree of hypercapnia may vary; more extensive tuberculous involvement or longer disease course suggest greater chance of type II respiratory failure.

[Delayed diagnosis or misdiagnosis of pulmonary tuberculosis: 458 cases clinical analysis].

Objective: To explore the reason of delayed diagnosis or misdiagnosis of pulmonary tuberculosis.

Method: The clinical data of 458 patients pulmonary tuberculosis patients undergoing treatment between January 1999 and December 2003 in our hospital were retrospectively analysed.

Results And Conclusion: The reasons for delayed diagnosis or misdiagnosis are as follows: A careless attitude towards health condition by patients themselves; neglected bacteriological evidence or ignorance of tuberculosis by physicians.