利用PVP添加剂提高钙钛矿太阳能电池光伏性能（英文）

研究了聚乙烯吡络烷酮(PVP)作为添加剂对CH3NH3Pb I3钙钛矿基太阳能电池光电性能的影响。通过SEM、XRD和UV-Vis等手段,研究了不同浓度PVP掺杂CH3NH3Pb I3钙钛矿前驱体对薄膜的表面形貌、结晶度和光学性能的影响。结果表明,少量的PVP添加可以调控钙钛矿薄膜的质量,添加了PVP的钙钛矿薄膜的吸收性能明显得到提高,且吸收峰红移了20 nm;同时,不仅增加了CH3NH3Pb I3的结晶度,而且还明显提高了钙钛矿薄膜的覆盖率,减少了钙钛矿薄膜中的针孔结构。在CH3NH3Pb I3前驱体溶液中添加质量分数为1%的PVP,得到的钙钛矿太阳能电池的能量转换效率达到8.38%。与未加PVP的标准电池器件效率(1.30%)相比,效率提高了544%。这些结果表明,通过添加剂来调控一步法CH3NH3Pb I3的晶体生长和薄膜形貌来获取高性能的钙钛矿太阳能电池是很有前途的。     

利用吡啶添加剂提高钙钛矿太阳能电池的光伏性能

研究了吡啶作为添加剂对一步法制备甲胺铅碘钙钛矿太阳能电池光电性能的影响.利用SEM、AFM、XRD、UV-Vis、PL等手段研究了不同吡啶掺杂浓度对制备的CH3 NH3 PbI3薄膜的表面形貌、结晶度和光学性能的影响.研究结果表明:少量的吡啶掺杂可以提高钙钛矿薄膜的覆盖率及降低薄膜的表面粗糙度.当在CH3 NH3 PbI3前驱体溶液中添加体积分数为1%的吡啶时,制备的钙钛矿太阳能电池的能量转换效率达到7.33%,而未加吡啶的对比器件效率仅为1.01%.进一步添加吡啶会导致钙钛矿材料的降解.     

利用PNA添加剂来调控钙钛矿薄膜结晶和覆盖率实现高效太阳能电池

钙钛矿薄膜形貌的控制是一个提高太阳能电池能量转换效率的关键问题,而引入添加剂是解决这一问题的一种有效而简便的方法。利用聚丙烯腈（PNA）作为CH₃NH₃PbI₃前驱体溶液溶剂添加剂,通过其浓度可以调控钙钛矿薄膜结晶和表面的覆盖率。本文通过SEM、XRD以及UV-Vis研究了PNA掺杂CH₃NH₃PbI₃钙钛矿薄膜后的表面形貌、结晶度和光学性能的变化。结果表明,通过添加少量的PNA可以优化钙钛矿薄膜的性能,其强烈影响薄膜的结晶过程,有助于形成均匀连续的薄膜,减少针孔,从而增强了钙钛矿层的覆盖率和光吸收。当PNA 的含量为1%（质量分数）时,钙钛矿太阳能电池的各项性能最佳,能量转换效率达到了8.38%。与未加PNA 的电池效率（1.31%） 相比,提高了540%。这些结果表明,PNA可以有效调控钙钛矿薄膜的晶体生长和薄膜形貌,在钙钛矿太阳能电池的大规模生产过程中是一种可以改善钙钛矿薄膜质量的有效添加剂。     

利用PNA添加剂来调控钙钛矿薄膜结晶和覆盖率实现高效太阳能电池（英文）

钙钛矿薄膜形貌的控制是一个提高太阳能电池能量转换效率的关键问题,而引入添加剂是解决这一问题的一种有效而简便的方法。利用聚丙烯腈(PNA)作为CH_3NH_3PbI_3前驱体溶液溶剂添加剂,通过其浓度可以调控钙钛矿薄膜结晶和表面的覆盖率。本文通过SEM、XRD以及UV-Vis研究了PNA掺杂CH_3NH_3PbI_3钙钛矿薄膜后的表面形貌、结晶度和光学性能的变化。结果表明,通过添加少量的PNA可以优化钙钛矿薄膜的性能,其强烈影响薄膜的结晶过程,有助于形成均匀连续的薄膜,减少针孔,从而增强了钙钛矿层的覆盖率和光吸收。当PNA的含量为1%(质量分数)时,钙钛矿太阳能电池的各项性能最佳,能量转换效率达到了8.38%。与未加PNA的电池效率(1.31%)相比,提高了540%。这些结果表明,PNA可以有效调控钙钛矿薄膜的晶体生长和薄膜形貌,在钙钛矿太阳能电池的大规模生产过程中是一种可以改善钙钛矿薄膜质量的有效添加剂。     

利用吡啶添加剂提高钙钛矿太阳能电池的光伏性能(英)

研究了吡啶作为添加剂对一步法制备甲胺铅碘钙钛矿太阳能电池光电性能的影响。利用SEM、AFM、XRD、UV-Vis、PL等手段研究了不同吡啶掺杂浓度对制备的CH_3NH_3Pb I_3薄膜的表面形貌、结晶度和光学性能的影响。研究结果表明:少量的吡啶掺杂可以提高钙钛矿薄膜的覆盖率及降低薄膜的表面粗糙度。当在CH_3NH_3Pb I_3前驱体溶液中添加体积分数为1%的吡啶时,制备的钙钛矿太阳能电池的能量转换效率达到7.33%,而未加吡啶的对比器件效率仅为1.01%。进一步添加吡啶会导致钙钛矿材料的降解。     

双添加剂处理电子传输层富勒烯衍生物[6,6]-苯基-C61丁酸甲酯对钙钛矿太阳能电池性能的影响

有机无机复合钙钛矿材料被证明是非常出色的光伏材料,目前主要通过优化钙钛矿材料的结晶和形貌来提高钙钛矿太阳能电池的效率.而对于电荷传输层,特别是p-i-n结构中电子传输层的研究相对较少.因此,本文制备了结构为ITO/PEDOT:PSS/CH3NH3Pb I3/PCBM/Al的钙钛矿太阳能电池通过在电子传输层富勒烯衍生物[6,6]-苯基-C61丁酸甲酯(PCBM)中添加聚苯乙烯(PS)和1,8-二碘辛烷(DIO)使得钙钛矿太阳能电池的光电转换效率从10.8%提升到了12.5%.分析了性能提高的原因主要是:1)添加剂PS的加入提升了PCBM的黏度,从而形成了质量更高、更平滑的膜层,这有利于抑制电子和空穴在钙钛矿层和电子传输层之间的复合;2)添加剂DIO的加入改善了电子传输层的形貌,有利于电荷的分离、传输和收集.研究结果表明用成本较低的添加剂处理可以改善电子传输层的形貌和膜层的质量达到了改善电荷传输特性的效果提升了钙钛矿太阳能电池的效率为提升钙钛矿太阳能电池性能提供了一条可行的路径.     

甲脒碘化铅单晶基钙钛矿太阳能电池的研究

近年来,CH(NH₂)₂PbI₃(FAPbI₃)由于其带隙接近理想值而受到了广泛关注,成为钙钛矿太阳能电池中最具吸引力的光电功能材料.然而由碘甲脒(FAI)和碘化铅(PbI₂)作为前驱体制备的传统钙钛矿层化学计量比不精准,缺陷密度大,稳定性差且结晶度较低,导致钙钛矿太阳能电池性能很难进一步提高.本文采用FAPbI₃单晶制备的钙钛矿薄膜具有高结晶度,高稳定性,精确的化学计量比和低缺陷密度.单晶钙钛矿薄膜的晶粒尺寸大,晶界少,导致晶界处缺陷较少,提高了钙钛矿太阳能电池的短路电流密度(J_SC)和开路电压(V_OC),使其光电转换效率有了大幅度的提高.本文为制备高稳定性、高结晶度和低缺陷密度的钙钛矿太阳能电池提供了一种有效策略.     

金纳米粒子增强钙钛矿的荧光发射

有机-无机杂化钙钛矿材料在钙钛矿发光二极管(PeLEDs)和激光器等光电器件中得到了新的应用,如何进一步提高钙钛矿薄膜的发光效率是目前的研究热点。将20nm粒径的金纳米粒子(Au NPs)掺杂至界面层PEDOT∶PSS中,可使以甲胺铅溴盐(CH3NH3PbBr3)薄膜为发光层的荧光强度提升了2.7倍。研究表明,Au NPs的引入有效增强了CH3NH3PbBr3薄膜的吸收,并提高了激子的辐射跃迁速率。同时,结合光学仿真进行分析,发现Au NPs的近场和远场表面等离激元均与钙钛矿薄膜吸收/发射区域有效耦合,从而最大程度地提高发光效率。提出利用Au NPs的近场和远场复合表面等离激元效应可最大程度地提高钙钛矿薄膜的荧光发射效率,该研究对制备高效率PeLEDs和激光器等提供了重要的理论指导和技术支持。     

石墨烯在钙钛矿太阳能电池中的应用

正近年来,基于有机-无机杂化钙钛矿材料的太阳能电池(简称钙钛矿太阳能电池,perovskite solar cells)因为具备优良的光电转换性能、成本低廉且易于规模化生产等特点,而在国际上备受关注。2009年CH3NH3Pb I3首次被用作染料敏化太阳能电池中的光吸收剂,获得了3.8%的光电转换效率,这掀起了钙钛矿太阳能电池的研究热潮。短短几年内,钙钛矿太阳能电池的光电效率得到迅速提升。最近美国国家能源部可再生能源实验室(NREL)认证的     

多步旋涂过程中CsPbBr3无机钙钛矿成膜机理

在无机钙钛矿太阳能电池的研究中,薄膜制备工艺是影响钙钛矿太阳能电池光电转换效率(PCE)的重要因素之一. CsPbBr₃钙钛矿作为稳定性极好的无机钙钛矿之一,因其前驱体盐(PbBr₂, CsBr)溶解度差异过大,通常采用多步法进行制备.而由于对成膜机理的认识不充分,导致制备的薄膜存在薄膜形貌差、前驱体反应不完全等问题.本文通过旋涂不同次数的CsBr溶液,探究了CsPbBr₃钙钛矿的成膜机理.成膜过程中CsBr扩散进入预先沉积的PbBr₂薄膜完成反应,短暂反应时间使薄膜深层反应不充分而薄膜表面过度反应,CsPb₂Br₅和Cs₄PbBr₆等相伴随CsPbBr₃钙钛矿出现,反复退火形成的薄膜阻挡CsBr扩散加剧了这一现象.适当地延长前驱体的反应时间,能为CsBr扩散及反应提供更充分的空间.基于优化反应时间, CsPbBr₃钙钛矿薄膜形貌得到改善、其晶粒尺寸得到提升,钙钛矿薄膜...     

Fine structure and isotope shift of the 3s4d 3 D-3s3p 3 P, 3s5d 3 D-3s3p 3 P and 3p 2 3 P-3s3p 3 P Transitions of MgI

Summary We report the measurements of the³ D(3s4d)-³ P(3s3p)³ D(3s5d)-³ P(3s3p), and³ P(3p ²)-³ P(3s3p) transition frequency of MgI, the fine-structure separation and isotope shift between²⁴Mg and²⁶Mg. The measurements have been performed in a metastable atomic beam; a good agreement is found for data already existing in the literature. The accuracy of the measurements reported in this paper is mainly limited by the Doppler broadening of theI ₂ transitions used as a reference and by the precision in the knowledge of the related wavelengths.     

The gas phase infrared band contours of s-triazine and s-triazine-d3: The fundamentals of C3N3H3 and C3N3D3 and some overtone and combination bands of C3N3H3

The systematic application of band contour techniques to account for most of the observed features of the ir spectra of s-triazine and s-triazine-d₃ have been made as well as a critique as to the limitations of such methods. The experimental and computer methods used to study the gas phase infrared band contours of s-triazine and s-triazine-d₃ are out-lined. Contours of the five E′ fundamentals of s-triazine have been recorded under moderate resolution and analyzed to give the Coriolis constants $\text{ζ}{}_{\mathrm{i}}{}^{\mathrm{z}}$, i = 6–10. The effects of l-resonance are very apparent for ν₈ and ν₉, in the form of holes in the Q branches of these bands. Under the highest resolution available, ν₆ and ν₁₀ also show l-resonance effects. Values of the l-doubling constants $\text{q}{}_{\mathrm{i}}{}^{\mathrm{(+)}}$ were obtained for these four fundamentals. One of the parallel A₂″ fundamentals of C₃H₃N₃ (ν₁₂) has also been studied. It lies close to ν₁₀(E′) and an A × E type of second-order Coriolis resonance may be the cause of the intensity enhancement observed in the inner wings of the ν₁₂ and ν₁₀ bands. Hot bands of the type (ν_i + nν₁₄ ? nν₁₄) have been observed in the contours of ν₈, ν₁₀, and ν₁₂. This is felt to be responsible for the large difference between our observed zeta sum (?1.30) and the theoretical sum (?1.00).The gas phase infrared band contours of the five E′ and 2A₂″ fundamentals of C₃N₃D₃ have also been recorded under moderate resolution. From P-R separations and by computer simulation of the contours, values of the Coriolis constants $\text{ζ}{}_{\mathrm{i}}{}^{\mathrm{z}}$ have been obtained for the E′ modes. The effects of l-resonance have been observed for ν₈(E′) and ν₁₀(E′) and values of the l-doubling constants $\text{q}{}_{\mathrm{i}}{}^{\mathrm{(+)}}$ have been estimated. An extensive series of hot bands of the type (ν₁₂ + nν₁₄ ? nν₁₄) has been observed in the contour of the ν₁₂ (A₂″) fundamental. The mass effect on the Coriolis constants has been discussed.Infrared band contours of the overtone 2ν₇ and seven degenerate E′ combination bands of C₃N₃H₃ have been recorded under moderate resolution. Analysis of these contours using the P-R separation method and computer simulation of the contours has given values of $\text{ζ}{}_{\mathrm{<mtext>eff</mtext>}}{}^{\mathrm{z}}$ for these bands. Fermi resonance between 2ν₇ and ν₆ has been analyzed. The importance of considering both the observed contour as well as the observed frequency when assigning higher tone bands is illustrated.     

Dielectric investigations of solid solutions SrTiO3-KTaO3 and SrTiO3-KNbO3

The temperature dependences of the dielectric constant and dielectric hysteresis loops in ceramic samples of (1 ? x)SrTiO_3?x KNbO₃ and (1 ? x)SrTiO_3?x KTaO₃ (0 ≤ x ≤ 0.3) solid solutions prepared using different heat treatments have been investigated. Phase diagrams of the studied solid solutions have been constructed in the T-x coordinates. It has been shown that, after quenching of samples (spontaneous cooling at room temperature after long-term heating at the sintering temperature of the ceramic samples), the temperature of the induced phase transition increases because of the weakening of random electric fields associated with nonisovalent impurities due to their “frozen” nonequilibrium redistribution. For small concentrations x, strong dielectric relaxation is observed in the temperature range of 150–250 K. A model of relaxing centers, which is based on the local charge compensation of heterovalent impurities, has been proposed.     

Ba3La(BO3)3基质中Tb3+的光致发光

以高温固相法合成了Ba3La(BO3)3∶Tb3 发光材料。在254nm紫外光激发下,研究了Ba3La(BO3)3∶Tb3 的激发光谱、发射光谱、发光强度与Tb3 浓度的关系。确定了Ba3La(BO3)3基质中Tb3 的自身浓度猝灭机理;探讨了助熔剂LiCO、敏化剂Ce3 、Bi3 的加入对荧光粉的发光强度的影响。     

Infrared spectra of matrix isolated BH3NH3, BD3ND3, and BH3ND3

The infrared spectra of ammonia-borane, BH₃NH₃, and two of its deuterated isotropic species, BD₃ND₃ and BH₃ND₃, isolated in argon matrix at liquid hydrogen temperature have been measured. Well resolved bands for these three isotopic species have been observed for all the fundamentals. A complete frequency assignment based on C₃v molecular symmetry has been made. A set of force constants have been calculated from the data for the two isotopes BH₃NH₃ and BD₃ND₃ using a valence force field. The agreement between experiment and frequencies calculated from these force constants for the mixed isotopic species, BH₃ND₃, substantiates the present assignment.     

Modulated magnetic structures of ErPb3, HoPb3, ErTl3 and HoTl3

Neutron diffraction experiments have been carried out on the magnetically ordered phases of ErPb₃, HoPb₃, ErTl₃ and HoTl₃. The magnetic moments were found to be sinusoidally modulated with a propagation vector of (0, 0.2, 0.5) for the Pb-compounds and (0.38, 0.38, 0.16) for the Tl-compounds.Work supported by the Bundesministerium für Forschung und Technologie     

Far Infrared Spectra of Ammonia-Boron Trifluoride: NH3BF3 and ND3BF3

Abstract

Spectra of polycrystalline samples of NH₃BF₃ and ND₃BF₃ at 300 K and 98 K have been recorded in the frequency range 20-400 cm^?1. Isotopic frequency ratios are used to interpret the observed features in terms of the known molecular and crystal structures.     

Improvement of Photoluminescence of Perovskite CH_3NH_3Pb I_3 by Adding Additional CH_3NH_3I during Grinding

The organic-inorganic hybrid perovskite CH_3NH_3PbI_3 has been a good candidate for many optoelectronic applications such as light-emitting diodes due to its unique properties.Optimizing the optical properties of the CH_3NH_3PbI_3 material to improve the device performance is a hot topic.Herein,a new strategy is proposed to enhance the light emission of CH_3NH_3PbI_3 phosphor effectively.By adding the reactant CH_3NH_3I powder in an appropriate proportion and simply grinding,the emission intensity of CH_3NH_3PbI_3 is greatly improved.The advantages of the proposed method are swiftness,simplicity and reproducibility,and no requirement for a complex organic ligand.The mechanism of this phenomenon is revealed by x-ray diffraction,scanning electron microscopy,energy dispersive spectroscopy,photoluminescence,and temperature-dependent photoluminescence.This study offers a unique insight for optimizing the optical properties of halide perovskite materials.     

Hyperfine suppression of 2 3 S 1--3 3 P J transitions in 3He

Two anomalously weak transitions within the 2(3)S_(1)--3(3)P_(J) manifolds in 3He have been identified. Their transition strengths are measured to be 1000 times weaker than that of the strongest transition in the same group. This dramatic suppression of transition strengths is due to the dominance of the hyperfine interaction over the fine-structure interaction. An alternative selection rule based on IS coupling (where the nuclear spin is first coupled to the total electron spin) is proposed. This provides qualitative understanding of the transition strengths. It is shown that the small deviations from the IS coupling model are fully accounted for by an exact diagonalization of the strongly interacting states.