高价离子掺杂对Bi系成相和结构的影响(II)

In our previous work we have found that the 2223 phase is formed more rapidly and the structural stability can be enhanced by doping high valence cation(Sn~(4+)、Sb~(5+)、V~(5+)、W~(6+)、Mo~(6+) etc.) in the Bi(Pb)SrCaCuO system. In this paper the effects of high valence cations doped on the phase formation and the crystal structure are discussed further.The Aurivillus building and rocksalt building unit coexist in the Bi double layers. The structural variety strongly affects the structural stability. Owing to Pb~(2+) addition the probability of Aurivillus building is increased, the stability of 2223 phase can be promoted. However, the structure is still not stable, since the addition of Pb~(2+) has decreased the valence state of Bi site and the oxygen positions are not fully occupied. By doping high valence cation, especially, when the valence of Pb_x~(2+)M_y~(n+) equals to +3 the structure of the 2223 phase can be stabilized. This result has been observed with examining elemental content of 2223 phase.The melting point of the grain boundaries are much lower after doping high valence cations, therefore the ion diffusion is more rapid and acceleration of the 2223 phase formation is observed.     

高纯氧化镧中稀土杂质的化学光谱分析

采用pH5.0和浓度为0.28M的α-羟基异丁酸为淋洗剂,强酸性阳离子交换色层法,分难富集高纯氧化镧中的14个稀土杂质元素。分离可在11小时内完成。稀土杂质富集物用复合载体 CsCl-聚氯乙烯碳粉吸附,发射光谱分析。加入回收实验的平均回收率为86～119％。此法可用于纯度为99.9995％的高纯氧化镧分析。     

超导相(Bi1.7Pb0.2In0.1)Sr2Ca2Cu3O10的制备和晶体结构研究

The superconducting phase(Bi_(1.7)Pb_(0.2)In_(0.1))Sr_2Ca_2Cu_3O_(10) with on-set T_c near 112K and zero resistivity at 95K has been prepared. The Unit cell is. body-centered tetragonal, space group I4/mmm, a=0.3.817(1) nm, c=3.704(1) nm. Chemical substitution of Pb and In in Bi—Sr—Ca—Cu—O series results in the growth of 2223 phase. The superconductivity and the formation mechanism are associated with the structural features.     

Factors influencing the performance of paintable carbon-based perovskite solar cells fabricated in ambient air

To date, many efforts have been made to improve the performance of paintable carbon-based(PC-based) perovskite solar cells(PSCs). Though great progress has been achieved, their power conversion efficiencies are still relatively low compared with hole-transport-materials-based PSCs. General research on influencing factors of performance in PC-based PSCs is still insufficient. In this work, PC-based PSCs were fabricated in ambient air and four groups of controlled experiments were performed in which the PbI_2 layers were prepared with or without antisolvent extraction treatment. These four groups of experiments were designed to find out the effect of different influencing factors on PC-based PSCs performance,for example, PbI_2 residual, the surface morphology of the perovskite film, the surface roughness of the perovskite film, and the contact status of the perovskite/carbon electrode interface. With a systematic analysis, we demonstrated that the contact status of the perovskite/carbon electrode interface played a vital role in PC-based PSCs, and a flat, smooth perovskite surface could help to improve this contact status significantly. Besides, on the precondition of a poor contact interface, no PbI_2 residual and a good surface morphology only brought limited benefits to the performances of PC-based PSCs.     

高价离子掺杂对Bi系成相和结构的影响(Ⅱ)

Sunshine等在BiSrCaCuO体系掺入Pb~(2+)取代部分Bi,经较长时间灼烧后.获得T_(c(0))?110 K以2223相为主的样品,Hongbao等又报导了用Sb部分取代Bi(Pb)SrCaCuO体系中的Bi的研究结果.我们曾用Sb~(5+)、Sn~(4+)、W~(6+)、Mo~(6+)等高价离子部分取代Bi,研究这些离子对BiSrCaCuO体系成相的影响,发现掺高价离子后2223相易于生成并易于得到T_(c(0))?111K的超导体.本文则进一步探讨高价离子掺入的影响及其加速2223相生成的原因。     

High-sensitive phototransistor based on vertical HfSe2/MoS2 heterostructure with broad-spectral response

Van der Waals heterostructures based on the two-dimensional (2D) semiconductor materials have attracted increasing attention due to their attractive properties. In this work, we demonstrate a high-sensitive back-gated phototransistor based on the vertical HfSe₂/MoS₂ heterostructure with a broad-spectral response from near-ultraviolet to near-infrared and an efficient gate tunability for photoresponse. Under bias, the phototransistor exhibits high responsivity of up to 1.42×10³ A/W, and ultrahigh specific detectivity of up to 1.39×10¹⁵ cm·Hz^1/2·W^-1. Moreover, it can also operate under zero bias with remarkable responsivity of 10.2 A/W, relatively high specific detectivity of 1.43×10¹⁴ cm·Hz^1/2·W^-1, ultralow dark current of 1.22 fA, and high on/off ratio of above 10⁵. These results should be attributed to the fact that the vertical HfSe₂/MoS₂ heterostructure not only improves the broadband photoresponse of the phototransistor but also greatly enhances its sensitivity. Therefore, the heterostructure provides a promising candidate for next generation high performance phototransistors.     

以B-γ-CsSnI3为光吸收层的平面异质结钙钛矿太阳能电池的模拟优化

采用AFORS-HET软件对以B-γ-CsSnI3作为光吸收层的平面异质结钙钛矿太阳能电池结构进行了模拟优化,其中TiO2作为电子传输层,Spiro-OMeTAD作为空穴传输层,讨论了钙钛矿太阳能电池光吸收层以及空穴传输层的各种参数对太阳能电池性能的影响.模拟优化得到B-γ-CsSnI3的PSCs最佳性能参数为:Voc=1.18 V,Jsc=24.48 mA/cm2,FF=80.04;,PCE=23.15;,效率虽略低于以CH3NH3PbI3作为光吸收层的钙钛矿太阳能电池,但考虑铅的毒性和钙钛矿电池的稳定性,以B-γ-CsSnI3作为光吸收层的PSCs将具有更好的应用前景.     

CsGeI3空穴传输层平面异质结钙钛矿太阳电池的模拟优化

采用AFORS-HET软件对CsGeI3空穴传输层(Hole Transport Material, HTM)平面异质结钙钛矿太阳电池进行了模拟,TiO2作为电子传输层,CH3NH3PbI3作为光吸收层,C作为背电极,分别讨论了钙钛矿光吸收层厚度、缺陷浓度,光吸收层/HTM界面态密度和HTM对太阳电池性能参数的影响.模拟优化得到CsGeI3 HTM的PSCs最佳性能参数为:Voc=1.199 V,Jsc=22.2 mA·cm-2,FF=86.22;,PCE=22.95;,效率虽略低于spiro作为HTM的器件,但考虑生产工艺和制备成本,CsGeI3作为HTM的PSCs将具有更好的应用前景.     

量子力学虚拟实验的MATLAB演示

量子力学是一门较抽象的科学.为了更直观、形象地展示量子力学中的一些物理原理和实验现象,本文利用MAT-LAB软件搭建了一个量子力学的虚拟演示平台,可以生动地演示电子双缝衍射、量子隧穿效应、氢原子电子云和斯塔克效应等现象.通过相关物理参数的输入以及物理现象的演示,可以使学生在量子力学的学习中获得更直观的教学感受.