[en] In the current work, a simplified hard templating approach is used to synthesise metal (Ag, Rh, Ir and Pt) containing structured carbon. The target metals are first introduced into the NaY zeolite template by wetness impregnation. The metals are carried in the super cages of the zeolite and subsequently embedded in the final structures after the steps of carbonisation and the template removal. Scanning electron microscopy images have confirmed that the carbon structures produced by this method retain the morphology of the original template. Transmission electron microscopy reveals the presence of dispersed metal particles in all the carbon structures produced. The metal loadings in these templated structures can reach 35 wt% without significant losses of surface areas and pore volumes. Selected carbon supported metals are tested for their catalytic activity for the methanation of carbon monoxide. The finding suggested that this method is effective in preparing metal nanoparticles for use as catalysts.

[en] Graphical abstract: An investigation based on the comparison between diverse cells that differ in either anode structures or fabrication methods was carried out to present reasonable clarification on the various factors to cell efficiencies of CdS/CdSe quantum dot co-sensitized solar cells. - Highlights: • Diverse quantum dot sensitized cells differing in either anode structures or fabrication methods were studied. • Two co-sensitization modes were compared in aspect of their impacts on the cell efficiencies. • The origins of basic battery parameter variations in diverse cells were explored. - Abstract: As a promising solar energy conversion device, quantum dot (QD) co-sensitized solar cells have been facing a great challenge of improving their efficiencies. To shed light on the possibilities and potential approaches of accomplishing such mission, this article presents an investigation based on the comparison between diverse cells including CdS/CdSe QD co-sensitized and solely sensitized ones, which differ in either anode structures or fabrication methods. We show the photoelectric characteristics and properties of two cells with CdSe@CdS and CdS@CdSe co-sensitization modes, respectively, and discuss the causes that influence the cell efficiencies in each modes. Subsequently, the two co-sensitization modes are compared each other in the aspects of anode structures, fabrication methods and their impacts on the basic battery parameters. By exploring the origins of the variations in basic battery parameters, we attempt to reach an access to reasonable clarification on the factors to cell efficiencies

[en] Zinc borosilicate glass is studied as a scintillating material. Glass samples with zinc oxide concentrations as high as 60 mol% were prepared successfully without deteriorating the glass-forming ability. Different post-preparation thermal treatments were carried out on the samples in the temperature range of 300-700 deg. C and for 3-8 h duration. A dominant emission band was observed near 400 nm in the luminescence spectra with the excitation peak near 260 nm. Photoluminescence decay kinetics shows dominant decay times of about 7-10 and 170-200 ns with a weak tail down to several tens of microseconds. Thermal treatment was found to enhance the 400 nm emission intensity several times with respect to an as-prepared sample and X-ray diffraction analysis confirmed the presence of ZnO crystallized phase in heavily annealed glass samples

[en] Objective: To evaluate the value and limitation of magnetic resonance imaging (MRI) in complete type endocardial cushion defect (ETECD). Methods: Eight patients (male 5, female 3) were scanned by MRI with ECG-gated spin echo (SE) and gradient echo (GE) cine techniques. The diagnosis of CTECD was made by X-ray plain film, echocardiography, X-ray right cardiac catheterization and angiocardiography, as well as MRI four patients were treated with operation. Results: Every chamber of the heart was enlarged, more serious in the right atrium and ventricle, with thickening of right ventricular wall on MRI in majority of cases. The endocardial cushion disappeared, so the four chambers of the heart were directly connected with each other, and presented a cross shape. Ventricular septal membrane defect and type I atrial septal defect were depicted also. The normal structure of mitral and tricuspid valves were not intact. There were 6 cases with pulmonary hypertension, 2 cases with Tetralogy of Fallot, 4 cases with right aorta arch and descending aorta, 1 patient with dextroverted heart and another with persistent left superior vena cava connected with coronary sinus. The cine MRI could directly depict the situation of left-right or right-left shunt at atrial and ventricular levels, and regurgitation from ventricles to atria, meanwhile the valves were depicted clearly. Conclusions: MRI can clearly demonstrate all anatomic deformation and complicated hemodynamic change of CTECD, as well as other coexistent deformations

[en] P-emitter formation has been an urgent issue in the fabrication of n-type silicon solar cells. The widely used BBr₃ diffusion process has advantages in cost and output but has disadvantages in safety and efficiency. In this work, we report on a new boron ester dopant, which was prepared by the complexation reaction between boron acid and D-mannitol. The boron ester was dissolved in a mixed solution of 1-Methoxy-2-propanol and H₂O to be compatible with the spin-on doping process. The mannitol helped to form a continuous B–O–C network, which improved the concentration and homogeneity of the boron dopants in the boron coatings. The composition of the boron source and the diffusion parameters, such as ambiance, period and temperature, were systematically varied to investigate the behaviour during spin-coating and diffusion. By relating these factors to the surface condition of the wafers and the resulting sheet resistance, it was found that the concentration and ratio of the mannitol/boron acid played a key role in the performance. The formed p-emitters could achieve a sheet resistance below 100 Ω/□ with the RSD (Relative Standard Deviation) remaining below 5% under the diffusion condition. (paper)

[en] The contact resistance between rear Ag and Al electrodes is of crucial importance to the electrical performance of crystalline silicon solar cells. In this article, we reported the effect of glass phase in Ag paste and sintering temperature on the contact resistance between rear Ag and Al electrodes. The interface microstructure of Ag/Al contact and the surface morphology of sintered Ag electrodes were observed with a field-emission scanning electron microscope (FE-SEM), and the interaction between the glass frit and metal (Ag and Al) powder was deeply discussed. The results of our study showed that the thickening of Ag-Al alloy layer because of the sintering temperature rising to accelerate the inter-diffusion between Ag and Al electrodes would lead to an increase in the Ag/Al contact resistance. However, the increase of either glass phase content in Ag paste or sintering temperature could facilitate the formation of Ag precipitates in the inter-miscible zone between Ag and Al electrodes, which may resulted in a decrease in the Ag/Al contact resistance. (paper)

[en] The reliability of crystalline silicon (c-Si) photovoltaic modules has a strong dependence on the silver (Ag) electrode solderability. To achieve desirable soldering, the reaction that occurs between Ag electrode and solder (Sn/Pb alloy) need to be comprehensively understood and elaborately controlled. In this article, the correlation of Ag electrode soldering states with intermetallic compound (Ag₃Sn) growth was discussed. It was found that the reaction dynamics of Ag electrode and solder was closely associated with the glass frit in Ag paste. Here taken for exemplification were three kinds of V–B–Si oxide glass frit, which led to diverse soldering states for the Ag electrode, e.g. inveracious soldering, appropriate soldering and over-soldering, owing to their different affection on the Ag₃Sn growth rate. The effect of glass frit on the Ag₃Sn growth was addressed from the aspects of glass phase transition temperature, distribution of glass phase in electrode, and reaction between glass and solder. In addition, it was also demonstrated that the amount of glass frit added in Ag paste might impose significant affection on the solderability of the sintered electrode.

[en] Since the application of silver (Ag) electrodes is of vital importance to the power output of crystalline silicon (c-Si) solar cells, the factors affecting Ag paste metallization contact performance on Si wafers need to get well understood. Herein, the correlation of Ag/Si contact resistivity and glasses used in Ag paste was studied comprehensively. Here taken for exemplification are three types of glass samples used in Ag paste, because the application of them can result in obvious differences in the contact interface characteristics as well as in the contact resistivity. It was found that the factors affecting contact resistivity include the formation of Ag colloids in the glass phase, the doping concentration in the contacted Si surface, and the fixed charge density and defect states density at the interface. In terms of these issues, the key functions and mechanisms of glasses used in Ag paste are elucidated, and also their effects on electrical performance of cells are discussed in this article.

[en] One of the decisive factors in realizing ohmic contact of silver (Ag) paste metallization on silicon (Si) wafers is the presence of Ag colloids in the glass phase at the Ag/Si interface. The Ag colloids are formed during the reaction between glass frit and Ag powder in the sintering process of Ag paste; thus, it is difficult to control the quantity of Ag colloids formed. In this study, we attempted to prepare a glass embedded with a large number of Ag colloids first to further improve the quality of ohmic contact of Ag paste metallization. In the PbO–TeO₂–SiO₂ glass system, a route was found for increasing the solubility of Ag in the glass melt by precipitating the Ce_1.88Pb_2.12O_6.53 crystal, which enabled a molar amount of recrystallized Ag colloids reach a high level of about 1/10 of oxides in the glass. As a result, the resistivity of the Ag/Si contact can be decreased substantially. The formation mechanism of Ag colloids in glass is revealed by various characterization and analysis methods, such as X-ray diffraction, electron energy loss spectroscopy, X-ray photoelectron spectroscopy, UV–visible and so on. Furthermore, it was also found that too high content of Ag in the glass melt would destroy the pyramid texture surface structure of Si wafers, which is not conducive to obtain high-quality Ag/Si ohmic contact. For this concern, optimal content of Ag colloids formed in glass is discussed.

[en] Environment-friendly supercapacitors demand the high-performance electrode materials working with neutral aqueous electrolyte. In this work, the nitrogen-doped ordered mesoporous carbons (NOMCs) have been synthesized and subsequently modified with molybdenum oxide nanoparticles (NPs) by a self-developed temperature controlled impregnation method. The prepared hybrids possess ordered mesoporous structure, high specific surface area (600–1000 m² g⁻¹), favorable pore size (∼4 nm) and well-dispersed uniform molybdenum oxide NPs. The results demonstrate that the nano-sized molybdenum oxides encapsulated in the ordered mesoporous channels exhibit significant electrochemical activity with an enhanced specific capacitance up to 410 F g⁻¹, which can be attributed to the nanosize effects from the nanopore confinement and efficient surface area of molybdenum oxide NPs under well dispersion. The hybrids exhibit quasi-rectangular CV curves within the enlarged potential window compared with the pristine NOMCs together with pairs of redox peaks owing to the multi-valance changes of molybdenum corresponding to the Faradaic reactions. Thus, the synthesized hybrids demonstrate not only the synergistic contribution of electrical double-layer capacitance and pseudocapacitance but also superior cycling stability in aqueous neutral electrolyte. (paper)