First principles total energy studies of the adsorption of germane on Ge(001)-c(2 × 4)

We perform first principles total energy calculations to study the energetics, and the atomic structure of the adsorption of germane (GeH₄) molecules on the Ge(001)-c(2 × 4) surface. The adsorption of a GeH₄ unit occurs after its dissociation into a germanium trihydride (GeH₃) and a hydrogen atom and a subsequent decomposition into a germanium dihydride (GeH₂) subunit and H atoms. Consequently, we first consider the adsorption of GeH₂ in two different configurations; the on-dimer and the intra-row geometries. Similar to the adsorption of SiH₂ and GeH₂ on Si(001), it is found that the on-dimer site is more stable than the intra-row geometry by 0.13 eV. However, in the adsorption of a GeH₂ fragment together with two H atoms we find that the intra-row geometry is energetically more favorable, again, similar to the adsorption of SiH₂ and GeH₂ (plus two H atoms) on the Si(001) surface.     

Concentrating Ge in zinc hydrometallurgical process with hot acid leaching-halotrichite method

1　INTRODUCTIONInthezincconcentratesfromHuidongLead zincMinelocatedinsouth westofChina ,therearerichraremetalssuchasGewhichhasverywideapplica tionsandhighvalue .However ,Gewaslargelywast edbecauseitwasdispersedinalotofresidues(halotrichiteresidue ,Ge Feresidueandhighacidleachedresidue)intheconventionalzinchydrometal lurgicalprocessforthezincconcentrates[1] .InordertoconcentrateandrecoverGe ,anovelhydrometal lurgicalprocess ,ie ,thehotacidleaching halotrichitemethodofzinchasbeendevelope…     

稀土化合物RE2Ge2In(RE=Ce,Pr,Nd)的磁性和晶场效应

基于晶场理论和分子场理论,采用点电荷晶场模型,通过模拟Zaremba小组的磁化率实验结果,得到了稀土化合物RE2Ge2In(RE=Ce,Pr,Nd)的晶场分裂能和相应波函数。计算表明,Kramer离子Ce3 和Nd3 在晶场效应的作用下简并部分消除得到了双基态,而非Kramer离子Pr3 分裂后得到了单基态。计算得到的Ce2Ge2In的第一激发能和总分裂能与Adroja小组中子散射实验结果吻合较好。     

Determination of hydrogen concentration in a-Si and a-Ge layers by elastic recoil detection analysis

In this work we have studied the individual a-Si and a-Ge hydrogenated layers prepared by RF sputtering on Si (100) substrates using Ar and H₂ gas mixture. The absolute value of atomic content of the H was determined by Elastic Recoil Detection Analysis (ERDA) with 1.6 MeV 4He⁺ beam. The dynamics of the out diffusion was investigated by annealing in high purity (99.999%) argon atmosphere at 350 °C for several hours. It was clearly shown that hydrogen can diffuse out faster from Ge film than from the Si one during annealing of the samples.     

电子辐照GaInP/GaAs/Ge三结太阳电池少子寿命的变化

为研究电子辐照空间太阳电池的损伤机制，对电子辐照GaInP/GaAs/Ge三结太阳电池进行了光致发光谱测量，分析了GaInP顶电池及GaAs中间电池发光强度随电子注量的变化规律。利用辐射效率关系对归一化发光强度随电子辐照注量的变化进行了拟合，分别得到了GaInP顶电池及GaAs中间电池在不同辐照条件下的少子非辐射复合寿命τ_nr，通过对比辐照前后少子非辐射复合寿命的衰降变化，发现GaInP顶电池的抗辐照性能优于GaAs中间电池。     

Measurements of Photon Mass Attenuation Coefficients for Ge and BGO Crystals at 10 Me V

The photon mass attenuation coefficients of the important materials for γ-ray detection, Ge and BGO (Bi₄Ge₃O₁₂) crystals, have been measured for 10.0 MeV γ-rays. The measurement system using the laser-Compton backscattering γ-rays and the high-resolution high-energy photon spectrometer has been developed and utilized. The effectiveness of the system achieving the total systematic uncertainties of 0.5% for the measurements of the photon mass attenuation coefficients was demonstrated. It was shown that the measured photon mass attenuation coefficients, 318.1 ± 1.7 [cm²/g] for the Ge crystal and 425.2 ± 2.4 [cm²/g] for the BGO crystal, agree within the achieved experimental uncertainties with the evaluated values including atomic and nuclear processes at 10.0 MeV.     

Fast,Scalable Synthesis of Micronized Ge3N4@C with a High Tap Density for Excellent Lithium Storage

Nanostructuring has significantly contributed to alleviating the huge volume expansion problem of the Ge anodes. However, the practical use of nanostructured Ge anodes has been hindered due to several problems including a low tap density, poor scalability, and severe side reactions. Therefore, micrometer-sized Ge is desirable for practical use of Ge-based anode materials. Here, micronized Ge₃N₄ with a high tap density of 1.1 mg cm⁻² has been successfully developed via a scalable wet oxidation and a subsequent nitridation process of commercially available micrometer-sized Ge as the starting material. The micronized Ge₃N₄ shows much-suppressed volume expansion compared to micrometer-sized Ge. After the carbon coating process, a thin carbon layer (≈3 nm) is uniformly coated on the micronized Ge₃N₄, which significantly improves electrical conductivity. As a result, micronized Ge₃N₄@C shows high reversible capacity of 924 mAh g⁻¹ (2.1 mAh cm⁻²) with high mass loading of 3.5 mg cm⁻² and retains 91% of initial capacity after 300 cycles at a rate of 0.5 C. Additionally, the effectiveness of Ge₃N₄@C as practical anodes is comprehensively demonstrated for the full cell, showing stable cycle retention and especially excellent rate capability, retaining 47% of its initial capacity at 0.2 C for 12 min discharge/charge condition.     

Ge quantum dots light-emitting devices

Si photonics becomes one of the research focuses in the field of photonics.Si-based light-emitting devices are one of the most important devices in this field.In this paper,we review the Si-based light...     

Atomistic Origin of the Enhanced Crystallization Speed and n‐Type Conductivity in Bi‐doped Ge‐Sb‐Te Phase‐Change Materials

Phase‐change alloys are the functional materials at the heart of an emerging digital‐storage technology. The GeTe‐Sb₂Te₃ pseudo‐binary systems, in particular the composition Ge₂Sb₂Te₅ (GST), are one of a handful of materials which meet the unique requirements of a stable amorphous phase, rapid amorphous‐to‐crystalline phase transition, and significant contrasts in optical and electrical properties between material states. The properties of GST can be optimized by doping with p‐block elements, of which Bi has interesting effects on the crystallization kinetics and electrical properties. A comprehensive simulational study of Bi‐doped GST is carried out, looking at trends in behavior and properties as a function of dopant concentration. The results reveal how Bi integrates into the host matrix, and provide insight into its enhancement of the crystallization speed. A straightforward explanation is proposed for the reversal of the charge‐carrier sign beyond a critical doping threshold. The effect of Bi on the optical properties of GST is also investigated. The microscopic insight from this study may assist in the future selection of dopants to optimize the phase‐change properties of GST, and also of other PCMs, and the general methods employed in this work should be applicable to the study of related materials, for example, doped chalcogenide glasses.