超薄异质结太阳能电池理论模拟计算及分析

采用AFORS-HET软件对超薄异质结太阳能电池的窗口层、本征层的掺杂浓度、厚度、带隙等参数进行了数值模拟和优化,结合实际具体分析了每个参数对超薄异质结电池性能的影响规律,且得出了最佳的优化参数。模拟结果表明:对于衬底厚度仅为80 μm的超薄异质结太阳能电池,随着窗口层厚度的增加,电池性能整体呈现下降的趋势,通过结合实际,得出窗口层的最佳厚度范围是5～9 nm;随着窗口层掺杂浓度的增加,电池性能整体呈现先增加后趋于恒定的趋势,窗口层理论上的最佳掺杂浓度范围为7×10¹⁹～8×10¹⁹;窗口层的带隙宽度对电池的开路电压和效率影响较大,对填充因子和短路电流有较小的影响,窗口层的最优带隙范围为1.85～2.0 eV。随着本征层厚度的增加,电池的填充因子FF和效率E_ff呈现先增加后减小的趋势,短路电流逐渐减小,而开路电压基本不变,本征层的最佳厚度是5～10 nm;当本征层的光学带隙小于1.8 eV时,对电池性能影响较小,当大于1.8 eV,电池性能急剧下降,因此本征层的最佳带隙范围是1.6～1.8 eV。     

光学窗口材料激光辐照热-力效应的解析计算研究

建立了高功率连续激光辐照透明光学材料的热力学模型,通过积分变换方法求解三维热传导方程,得出了激光辐照引起的瞬态温度场分布的精确解析解,并在此基础上进一步求得热应力场的瞬态分布。以1.315μm的高能氧碘激光辐照熔石英玻璃为例,计算了熔石英在激光辐照下的温度场与热应力场分布,分析了其激光损伤机理。研究结果表明由于熔石英具有优良的热稳定性,温度不均匀分布所产生的热应力相对较小,激光损伤主要是受辐照区域温度值超过材料熔点发生熔融破坏。理论分析结果与相关的实验结论一致,说明所建立激光辐照效应模型的合理性。     

Automatic window factor analysis—A more efficient method for determining concentration profiles from evolutionary spectra

An algorithm called automatic window factor analysis (AUTOWFA) is developed for the purpose of determining, efficiently and automatically, the concentration profiles of the spectroscopically active components present in evolutionary processes, such as chemical titration, chromatography and kinetics. The method not only yields windows and profiles in agreement with those reported in the literature, but also reveals components not detected by precursor techniques. The method, however, has not been optimized and may require user interaction to fine-tune the windows.     

Construction of systematic (k + 1,k) memory MDS sliding window codes over embedded fields

In this paper, based on the structure of embedded fields, we investigate explicit construction of systematic $(k+1,k)$ mMDS sliding window codes with memory $m=2,3$. First, over GF($2^{lh}$) with $l\ge 1$ and $h\ge 2$, we propose an algorithm to construct $(2^{lh-1}+1,2^{lh-1})$ mMDS codes with memory 2, which are optimal in the sense that $2^{lh-1}$ is the maximum possible value of k for a $(k+1,k)$ sliding window code with memory 2 over GF($2^{lh}$) to be mMDS. When $l\ge 2$, every constructed code has the extra property that it contains a $(2^{h-1}+1,2^{h-1})$ mMDS sliding window code with memory 2 as a subcode over the subfield GF($2^h$). Next, over GF($2^{2lh}$) with $l\ge 1$ and $h\ge 2$, we introduce a method to construct $(k+1,k)$ mMDS codes memory 3, and a few new codes have been obtained consequently. When $l\ge 2$, every code constructed by the new approach also has the property that it contains an mMDS subcode over the subfield GF($2^{2h}$). The embedding subfield-subcode property enhances the flexibility and efficiency of the designed codes.     

NIR-II fluorescent nanophosphors for bio-imaging

The design of nanoprobes in the second window near-infrared region has grasped a substantial amount of attention due to the flexible emission in the second near-infrared region (NIR-II) region (1,000–1,700 nm). In addition, this region provides the advantage of reduced photon scattering with less autofluorescence for improvement during in vivo fluorescence imaging. NIR-II nanoprobes such as quantum dots, AIEgens, carbon nanotubes, and polymers are in a constant state of evolution for improved NIR-II emission. Among these probes, lanthanides are explored the most for NIR-II imaging applications. Moreover, nanophosphors, although in their nascent form, are interesting compounds due to their good luminescence properties with efficient energy transfer processes. Our review aims to give insight into nanophosphors, mainly for biological imaging applications. We will also provide a comparative study of lanthanides and nanophosphors for understanding the mechanism and importance of nanophosphors in the future bio-imaging field.