Nanoscale semiconductor Pb1−xSnxSe (x = 0.2) thin films synthesized by electrochemical atomic layer deposition

In this paper the fabrication and characterization of IV-VI semiconductor Pb_1−xSn_xSe (x = 0.2) thin films on gold substrate by electrochemical atomic layer deposition (EC-ALD) method at room temperature are reported. Cyclic voltammetry (CV) is used to determine approximate deposition potentials for each element. The amperometric I-t technique is used to fabricate the semiconductor alloy. The elements are deposited in the following sequence: (Se/Pb/Se/Pb/Se/Pb/Se/Pb/Se/Sn …), each period is formed using four ALD cycles of PbSe followed by one cycle of SnSe. Then the deposition manner above is cyclic repeated till a satisfactory film with expected thickness of Pb_1−xSn_xSe is obtained. The morphology of the deposit is observed by field emission scanning electron microscopy (FE-SEM). X-ray diffraction (XRD) pattern is used to study its crystalline structure; X-ray photoelectron spectroscopy (XPS) of the deposit indicates an approximate ratio 1.0:0.8:0.2 of Se, Pb and Sn, as the expected stoichiometry for the deposit. Open-circuit potential (OCP) studies indicate a good p-type property, and the good optical activity makes it suitable for fabricating a photoelectric switch.     

Tm-Ho and Tm-Tb energy transfer in tellurite glass

In Tm³⁺-Ho³⁺- and Tm³⁺-Tb³⁺-doped tellurite glasses, the IR fluorescence spectra and the lifetimes of the upper ³H₄ and lower ³F₄ lasing levels for 1.47 μm of Tm³⁺ were measured. The non-exponential decay is fitted using the Inokuti-Hirayama equation. The energy-transfer parameter C_DA, critical ion distance R₀, lifetime and non-radiative energy-transfer efficiency η between donor and acceptor ions are compared. The quenching mechanism has been explained. Both Ho³⁺ and Tb³⁺ ions reduce the lifetimes of the upper and lower lasing levels, with Tb³⁺ ions proving more efficient than the effects observed for Ho³⁺ ions. The optimised Tb₂O₃ concentration is about 1.0-1.5 wt%, which produced effective inversion and could be used for laser and amplifier applications.     

Thermal behavior and failure mechanism of large format lithium-ion battery

Journal of Solid State Electrochemistry - Thermal runaway (TR) behavior of 38 Ah lithium-ion batteries with various states of charge (SOC) is experimentally investigated in this work using...     

Establishment of Galectin-3 Time-resolved Fluoroimmunoassay and its Application in Idiopathic Membranous Nephropathy

Journal of Fluorescence - The aim of this study was to establish a time-resolved fluorescent immunoassay (TRFIA) for the detection of serum Galectin-3 (Gal-3) and apply this method to evaluate the...     

Compositional effects and spectroscopy of rare earths (Er, Tm, and Nd) in tellurite glasses

Tellurium oxide glass hosts have exceptionally large solubility for RE-ions. In this paper, the relationship between the host glass composition and spectroscopic properties of Er³⁺-doped and Tm³⁺-doped tellurite glasses and fibres has been examined in detail. In particular, the effect of compositional modification on the line-shapes of the transitions: ⁴I_13/2→⁴I_15/2 in Er³⁺-doped and ³H₄→³F₄ in Tm³⁺-doped tellurite glasses is analysed and discussed. The presence of co-dopants, namely Tb³⁺ and Ho³⁺ ions in Tm³⁺-doped glasses on the lifetimes of the upper (³H₄) and the lower (³F₄) levels have also been discussed for shortening the lifetime of the transition between the ³F₄ level and the ground state in thulium. The spectroscopic properties of Nd³⁺-doped glasses for designing amplifiers operating in the 1330- to 1370-nm region has also been explained for demonstrating a continuous gain spectrum from 1310- to 1610-nm. The fibre loss measurements demonstrate that the Er-doped fibres have less than 880 dB km^–1 attenuation in the 1200- to 1400-nm range. An explanation is given to determine the suitability of such RE-doped tellurite fibres for designing broadband amplifiers.     

氯化苯并咪唑镧的荧光光谱

对新合成的化合物氯化苯并咪唑镧HCl₄·[C₇H₆N₂(H₂O)₂]₂La及其LaCl₃·5H₂O的水溶液进行了三维荧光光谱测定,讨论了HCl₄·[C₇H₆N₂(H₂O)₂]₂La在不同波长的光激发下的荧光特性,荧光强度与浓度的关系及标题化合物的上转换荧光,即在540nm绿光的激发下可以获得紫外光(290nm)和近紫外光(360nm).     

400 mW ultrashort cavity low-noise single-frequency Yb³⁺-doped phosphate fiber laser

A compact, low-noise, single-frequency fiber laser by using a newly developed Yb3? heavily doped single-mode phosphate glass fiber has been demonstrated. Over 400 mW stable continuous wave single transverse and longitudinal mode laser at 1.06 μm was achieved from a 0.8 cm long active fiber. The measured slope efficiency and estimated quantum efficiency of laser emission are 72.7% and 93%, respectively. The signal-to-noise ratio is higher than 72 dB, and the linewidth of the fiber laser is less than 7 kHz, while the measured relative intensity noise is less than -130 dB/Hz at frequencies of over 1.5 MHz.     

Revisiting the polyoxometalate-based late-transition-metal-oxo complexes: the "oxo wall" stands

Terminal oxo complexes of the late transition metals Pt, Pd, and Au have been reported by us in Science and Journal of the American Chemical Society. Despite thoroughness in characterizing these complexes (multiple independent structural methods and up to 17 analytical methods in one case), we have continued to study these structures. Initial work on these systems was motivated by structural data from X-ray crystallography and neutron diffraction and (17)O and (31)P NMR signatures which all indicated differences from all previously published compounds. With significant new data, we now revisit these studies. New X-ray crystal structures of previously reported complexes K(14)[P(2)W(19)O(69)(OH(2))] and "K(10)Na(3)[Pd(IV)(O)(OH)WO(OH(2))(PW(9)O(34))(2)]" and a closer examination of these structures are provided. Also presented are the (17)O NMR spectrum of an (17)O-enriched sample of [PW(11)O(39)](7-) and a careful combined (31)P NMR-titration study of the previously reported "K(7)H(2)[Au(O)(OH(2))P(2)W(20)O(70)(OH(2))(2)]." These and considerable other data collectively indicate that previously assigned terminal Pt-oxo and Au-oxo complexes are in fact cocrystals of the all-tungsten structural analogues with noble metal cations, while the Pd-oxo complex is a disordered Pd(II)-substituted polyoxometalate. The neutron diffraction data have been re-analyzed, and new refinements are fully consistent with the all-tungsten formulations of the Pt-oxo and Au-oxo polyoxometalate species.     

Dicubyl disulfide

Dicubyl disulfide (1) has been prepared in six steps from commercially available dimethyl-1,4-cubanedicarboxylate in 47% overall yield. In the final step, the previously unknown cubanethiol 2 was oxidized to disulfide 1. X-ray crystallography for 1 reveals the shortest tetragonal C-S bond on record (1.771 A). In contrast to previous generalizations, density functional theory calculations predict a low S-S rotation barrier similar to that for t-BuSSBu-t. Low-temperature (13)C NMR (600 MHz) confirms the prediction.     

980-nm diode-pumped Tm(3+)/Yb(3+)-codoped tellurite fiber for S-band amplification

We report gain measurements in Tm(3+)/Yb(3+)-codoped tellurite glass fibers in the 1460-1530-nm region using a conventional 980-nm pumping scheme. The gain spectrum is dependent on the geometry of the fiber and the length owing to the superfluorescence upconversion pump scheme.