Temperature-dependent photoluminescence of lead-free cesium tin halide perovskite microplates

Tin halide perovskites recently have attracted extensive research attention due to their similar electronic and band structures but non-toxicity compared with their lead analogues. In this work, we prepare high-quality CsSnX_(3)(X=Br,I) microplates with lateral sizes of around 1–4 μm by chemical vapor deposition and investigate their low-temperature photoluminescence(PL) properties. A remarkable splitting of PL peaks of the CsSnBr_(3)microplate is observed at low temperatures. Besides the possible structural phase transition at below 70 K, the multi-peak fittings using Gauss functions and the power-dependent saturation phenomenon suggest that the PL could also be influenced by the conversion from the emission of bound excitons into free excitons. With the increase of temperature, the peak position shows a blueshift tendency for CsSnI_(3), which is governed by thermal expansion. However, the peak position of the CsSnBr3microplate exhibits a transition from redshift to blueshift at ~160 K. The full width at half maximum of CsSnX_(3)broadens with increasing temperature, and the fitting results imply that longitudinal optical phonons dominate the electron–phonon coupling and the coupling strength is much more robust in CsSnBr3than in CsSnI_(3). The PL intensity of CsSnX_(3)microplates is suppressed due to the enhanced non-radiative relaxation and exciton dissociation competing with radiative recombination. According to the Arrhenius law, the exciton binding energy of CsSnBr_(3)is ~38.4 meV, slightly smaller than that of CsSnI_(3).

4PL供应链融资体系多方安全隐私计算的信息共享机制研究

目前4PL供应链融资业务随着技术的提升,在获取大数据信息的同时,也产生了“信息壁垒”“数据泄露”“数据权限”等信息安全共享问题。在4PL供应链融资业务中,在隐私安全的基础上提升数据资源共享。文章首先分析目前4PL供应链融资结构和要素关系及相关信息流通问题,然后从数据安全共享的层面出发,结合隐私计算的多方安全计算技术,构建了一种安全的4PL信息平台并分析其共享机制用以增加参与主体间的信任度,从而提高4PL供应链融资的效率,并且建立数据管控系统和动态协作管理架构以增强4PL企业在供应链融资中的功能。

数字普惠金融赋能县域产业结构转型升级的动力机制——基于PLS-SEM模型分析

基于偏最小二乘法结构方程模型(PLS-SEM),运用河南省县域2014—2020年平衡面板数据研究数字普惠金融驱动河南省县域产业转型升级的机制与实证效果,结果表明:数字普惠金融能够推动河南省县域产业结构的转型升级;数字普惠金融主要通过经济发展、生态环境、社会共享三个方面共同推动河南省县域产业结构转型升级;从发展潜力方面看,数字普惠金融对产业结构升级有一定负相关性,可能的原因是河南省县域数字平台不够完善、数字信息技术落后,且大多以轻工业、农业为主,导致数字普惠金融的正向融入性存在延迟。必须持续推动数字普惠金融的产业融入性、夯实数字普惠金融服务实体经济的功能性,提高河南省县域产业经济韧性。

Ostensibly perpetual optical data storage in glass with ultra-high stability and tailored photoluminescence

Long-term optical data storage(ODS)technology is essential to break the bottleneck of high energy consumption for information storage in the current era of big data.Here,ODS with an ultralong lifetime of 2×10^(7)years is attained with single ultrafast laser pulse induced reduction of Eu^(3+)ions and tailoring of optical properties inside the Eu-doped aluminosilicate glasses.We demonstrate that the induced local modifications in the glass can stand against the temperature of up to 970 K and strong ultraviolet light irradiation with the power density of 100 kW/cm^(2).Furthermore,the active ions of Eu^(2+)exhibit strong and broadband emission with the full width at half maximum reaching 190 nm,and the photoluminescence(PL)is flexibly tunable in the whole visible region by regulating the alkaline earth metal ions in the glasses.The developed technology and materials will be of great significance in photonic applications such as long-term ODS.

Synthesis and Photoluminescence of New Europium Complex Eu(DBM)_3(DPPZ) with Dipyridophenazine Ligand

Dipyrido [3, 2-a:2,3-c] phenazine moiety has been introduced as neutral ligand in europium complex. Therefore, a new europium complex with saturated emission, strong fluorescent intensity and good solubility was designed and synthesized for the first time. Its photoluminescence and UV properties were examined. The experimental results showed that this new Eu-complex could be used as red electroluminescent materials.

Red Electroluminescence and Photoluminescence from Novel Binuclear Europium Complex with Squaric Acid Ligand

A novel binuclear europium P-diketone complex with squaric acid ligand was synthesized for the first time. Its structure was elucidated by IR, UV, and Elemental Analysis. Red light emitting diode (LED) was fabricated by using the novel europium complex as an emitting layer, tris(8-quinolinolate) aluminum (III) (Alq(3)) as an electron-transporting layer, N, N'-diphenyl-N, N'-(3-methylphenyl)-1,1'-biphenyl-4,4'-diamine (TPD) as a hole-transporting layer. A cell structure of indium-tin-oxide/TPD/Eu-complex/Alq(3)/Mg: Ag was employed. Red electroluminescence was observed at room temperature with dc bias voltage of 2 V in this cell. 2 Red emission peaks at about 613 nm with maximum luminance of over 106 cd/m(2). Compared with the EL luminance from those europium complexes reported before, one from the Eu-complex is best in the same cells.

A Series of Mononuclear Complexes Constructed from Transition Metals and Amino Acid Derived Ligands: Syntheses, Structures and Photoluminescence

Eight neutral mononuclear complexes constructed from transition metals （M = Co（Ⅱ）, Ni（Ⅱ）, Cu（Ⅱ）, Zn（Ⅱ）, Cd（Ⅱ）） and ligands N-（2-pyridylmethyl）-L-phenylalanine （L-Hpmpa） and N-（2-pyridylmethyl）-L-tyrosine （L-Hpmtyr） have been synthesized by both hydrothermal and conventional room temperature reactions. Four of them have been structurally characterized by single-crystal X-ray diffractions. They are： [Co（L-pmpa）2·2H2O] 1, [Ni（L-pmpa）2·2H2O] 2, [Cu（L-pmpa）2·2H2O] 3 and [Cu（L-pmtyr）2·2H2O] 4. Single-crystal X-ray analysis, IR and elemental analysis revealed that complexes 1, 2 and 3 are isostructural. Powder X-ray diffraction, IR and elemental analysis revealed that complexes 4, 5 （Zn[L-pmtyr]2·2H2O）, 6 （Cd[L-pmtyr]2·2H2O）, 7 （Co[L-pmtyr]2·2H2O） and 8 （Ni[L-pmtyr]2·2H2O） are isostructural. The photoluminescence properties of L-Hpmtyr ligand, compounds 5 and 6 were also investigated.

Preparation, Structure, Photoluminescence and Energy Transfer Mechanism of a Novel Holmium Complex

A novel holmium complex [Ho(HIA)_2(H_2O)_4(NO_3)](NO_3)_2(1, HIA = isonicotinic acid) has been synthesized through hydrothermal reactions and characterized by single-crystal X-ray diffraction. Complex 1 crystallizes in the C2/c space group of monoclinic system: a = 14.4797(7), b = 12.4768(2), c = 13.3471(5) ?, β = 118.690(4)°, V = 2115.26(13) ?~3, C_(12)H_(16)HoN_5O_(17), Mr = 667.23, Z = 4, Dc = 2.095 g/cm^3, μ(Mo Kα) = 3.838 mm^(–1) and F(000) = 1304. The crystal structure of 1 is characterized by an isolated structure. Solid-state photoluminescence experiment uncovers that it shows yellow light emission. The emission bands are originated from the characteristic emission of the 4 f electrons intrashell transition of the ~5S_2 → ~5I_8 and ~5F_5 → ~5I_8 of the Ho^(3+) ions. Energy transfer mechanism is explained by the energy level diagram of the Ho3+ ion and the isonicotinic acid ligand. It has remarkable CIE chromaticity coordinates of(0.4929, 0.4632), so it may be a promising color converter for lighting and displays.

Pls3突变相关新型早发骨质疏松大鼠模型的心血管改变及机制

目的基于自主构建的丝束蛋白3(Plastin 3,PLS3)大片段基因Pls3敲除的新型骨质疏松大鼠模型,评估心血管表型及其与胶原代谢的关系。方法采用CRISPR/Cas9技术构建Pls3基因10~16外显子大片段敲除的大鼠模型(Pls3^(E10-16del/0)),与野生型大鼠进行心脏表型比较,采用免疫组化染色了解PLS3蛋白在心血管的表达,采用超声心动评估大鼠心血管形态及功能,HE染色了解心脏组织学改变,使用扫描电镜评估心脏胶原蛋白的微结构及排列。结果PLS3在野生型大鼠心血管组织细胞质中广泛表达,在Pls3^(E10-16del/0)大鼠心血管的表达明显减少。6~8周龄Pls3^(E10-16del/0)大鼠的心脏及大血管结构与功能未见明显异常,但与野生型大鼠相比,其存在右心室舒张末内径及近端升主动脉内径缩小,血管内皮细胞减少及排列紊乱。Pls3^(E10-16del/0)大鼠心血管组织中的胶原合成未受影响,但电镜下可见其心脏及升主动脉中的细胶原纤维断裂、排列散乱。结论本研究首次对新型Pls3基因大片段敲除的早发骨质疏松大鼠模型心血管系统进行研究,发现其右心室及升主动脉内径缩小,出现细胶原纤维断裂、排列散乱的异常改变,其对心血管系统的结构与功能的远期影响,有待观察,研究拓展了对Pls3相关骨质疏松症心血管表型的认识。

Red Mechanoluminescence and Photoluminescence from Novel Europium Complexes

Two new binuclear (europium and lanthanum) beta-diketone complexes Eu0.9La0.1(TTA)(3)Phen and Eu0.5La0.5(TTA)(3)Phen in which Phen is 1,10-phenanthroline, TTA is an anion of thenoyltrifluoroacetone (HTTA) were synthesized for the first time. They showed intense photoluminescence (PL) and mechanoluminescence (ML), and had their maximum PL and ML spectra peaked at 613.5 nm with half bandwidth of 10 nm respectively. Their PL and ML intensity were obviously stronger than these from Eu(TTA)(3)Phen. It is considered that binuclear (europium and lanthanum) beta-diketones complexes are promising ML and PL materials.

Construction and Photoluminescence Properties of Zn(Ⅱ)/Cd(Ⅱ) Complexes with 4-Amino-3,5-propyl-1,2,4-triazole Ligand

Reaction of ZnCI2 and 4-amino-3,5-propyl-1,2,4-triazole （dpatrz） or CdC12, NaN3 and dpatrz, in aqueous solution at room temperature yields two neutral clusters： a dinuclear complex [Zn2（dpatrz）2Ch] （I） and a linear trinuclear complex, [Cd3（dpatrz）4（N3）2Cl4] （II）. Both complexes have been characterized by X-ray single-crystal diffraction, powder XRD, IR, elemental analysis, TG and fluorescence analysis. Complex I crystallizes in orthorhombic, space group Pbca with a = 11.865（2）, b = 14.464（3）, c = 15.985（3） A, V= 2743.4（9） A3, Z = 4, C16H32NsCI4Zn2, Mr = 609.4, Dc = 1.475 g.cm3, p = 2.16 mm-1, F（000） = 1248, GOOF = 1.091, the final R = 0.0295 and wR = 0.0665 for 1999 observed reflections （I 〉 2a（/））. Complex Ⅱcrystallizes in monoclinic, space group P2/c with a = 11.408（2）, b = 15.211（3）, c = 18.152（6） A, fl = 123.75（2）°, V = 2619.1（1） A3, Z = 2, C32H64N22ClaCd3, Mr = 1236.05, Dc = 1.567 g.cm3, p = 1.46 mm-1, F（000） = 1244, GOOF = 1.042, the final R = 0.0444 and wR = 0.0913 for 3466 observed reflections （I 〉 2a（/））. The analysis of X-ray revealed that both structures lie about the inversion centers： complex I adopts two pl,2-triazole bridges linking two Zn（II） ions and II forms a linear trinuclear structure with four μ1,2-triazoles and two/μIA-N3 bridging modes. There are different coordinated geometries for three Cd（II） ions in Ⅱ： one is coordinated with an octahedral environment, and the other two are distorted tetragonal pyramids （r = 0.34）. The hydrogen bonds of C-H...C1 and N-H...C1 lead to the discretes into a 3D supramolecular network in both compounds. The thermal stabilities and photoluminescence behaviors of them were also studied.

Surface plasmon enhanced photoluminescence in amorphous silicon carbide films by adjusting Ag island film sizes

Ag island films with different sizes are deposited on hydrogenated amorphous silicon carbide （a-SiC：H） films, and the influences of Ag island films on the optical properties of the tx-SiC：H films are investigated. Atomic force microscope images show that Ag nanoislands are formed after Ag coating, and the size of the Ag islands increases with increasing Ag deposition time. The extinction spectra indicate that two resonance absorption peaks which correspond to out-of-plane and in-plane surface plasmon modes of the Ag island films are obtained, and the resonance peak shifts toward longer wavelength with increasing Ag island size. The photoluminescence （PL） enhancement or quenching depends on the size of Ag islands, and PL enhancement by 1.6 times on the main PL band is obtained when the sputtering time is 10 min. Analyses show that the influence of surface plasmons on the PL of a-SiC：H is determined by the competition between the scattering and absorption of Ag islands, and PL enhancement is obtained when scattering is the main interaction between the Ag islands and incident light.

Photoluminescence evolution in self-ion-implanted and annealed silicon

Si^＋ ion-implanted silicon wafers are annealed at different temperatures from room temperature to 950℃ and then characterized by using the photoluminescence （PL） technique at different recorded temperatures （RETs）. Plentiful optical features are observed and identified clearly in these PL curves. The PL spectra of these samples annealed in different temperature ranges are correspondingly dominated by different emission peaks. Several characteristic features, such as an R line, S bands, a W line, the phonon-assistant WTA and SiTO peaks, can be detected in the PL spectra of samples annealed at different temperatures. For the samples annealed at 800℃, emission peaks from the dislocations bounded at the deep energy levels of the forbidden band, such as D1 and D2 bands, can be observed at a temperature as high as 280 K. These data strongly indicate that a severe transformation of defect structures could be manipulated by the annealing and recorded temperatures. The deactivation energies of the main optical features are extracted from the PL data at different temperatures.

冰草1PS和1PL易位染色体导入不同小麦背景改良株型的遗传效应评价

冰草(Agropyron cristatum L.,2n=4x=28,PPPP)携带的多样性外源基因是小麦遗传改良重要基因源。前期研究表明冰草1P染色体上的基因可以改良小麦株叶型,但在获得易位系的基础上,外源片段导入不同背景小麦品种的叶型变化以及可能带来的不利遗传连锁累赘还不清楚。为进一步探究小麦-冰草T1PS·1AL和T1AS·1PL易位系在不同小麦背景中对主要农艺性状的遗传效应,本研究将小麦-冰草1PS、1PL易位系与藁城8901、百农607、漯麦163、百农207、西农979、中麦578、川麦104、宁麦资126等8个普通小麦品种进行杂交,对F2分离群体的农艺性状进行考察和分析。结果表明,冰草1PS染色体导入小麦后,降低了小麦的倒三叶长,株高也显著降低3~8 cm,产量性状基本不受影响。冰草1PL染色体使小麦株高降低,旗叶、倒二叶和倒三叶显著缩短,改变株型的同时,小麦的产量性状同时降低,具有连锁累赘。在冰草1P易位系中,后代的表型除与染色体本身所产生的效应有关外,也与小麦受体的遗传背景相关。在不同背景的小麦亲本杂交组合后代中,可以选出株叶型改良且产量性状不受影响的单株用于小麦的遗传改良。研究表明2个小麦-冰草1P易位系创新种质在株型改良上具有显著的遗传效应,可以为冰草1P染色体易位片段的利用提供指导。

Explanation of Unusual Photoluminescence Behavior from InAs Quantum Dots with InAlAs Capping

The effect of different kinds of cap layers on optical property of InAs quantum dots （QDs） on GaAs （100） substrate was studied. Temperature dependent photoluminescence （PL） indicates that the PL integrated intensity from the ground state of InAs QDs capped with an intermediate InAIAs layer drops very little as compared to QDs capped with a thin InGaAs or GaAs cap layer from 15 K up to room temperature. PL integrated intensity ratio of the first excited to ground states for InAs QDs capped with an intermediate InAIAs layer is unexpectedly decreased with increasing temperature, which are attributed to phonon bottleneck effect. A virtual barrier is proposed to describe this physics process and shows good agreement with experimental results when fitting the curve with the value of the virtual barrier 30 meV.

Photoluminescence study on Eu-implanted GaN

The photoluminescence （PL） properties of Eu-implanted GaN thin films are studied. The experimental results show that the PL intensity is seriously affected by ion implantation conditions. The PL efficiency increases exponentially with annealing temperature increasing up to a maximum temperature of 1050℃. Moreover, the PL intensity for the sample implanted along the channelling direction is nearly twice more than that observed from the sample implanted along the random direction. The thermal quenching of PL intensity from 10K to 300K for sample annealed at 1050℃ is only 42.7%.

Synthesis and Photoluminescence Properties of Rare Earth Complexes with 3-Allyl-2, 4-Pentanedione

In order to combine the merits of rare earth organic complexes with excellent material performances of polymers, a polymerizable chelating agent, 3-allyl-2, 4-pentane dione (APD), was synthesized by phase transfer catalysis and its rare earth complexes were prepared. The compounds were characterized by EA, IR and (()~1H NMR.) Their UV spectra and fluorescence spectra were investigated. The effects of allyl on the luminescence properties of the complexes were studied. The results show that the sensitization of APD is changed by allyl in comparison with that of acetyl acetone (acac), and it becomes an ideal novel ligand of Eu. In addition, intramolecular energy transfer mechanism in the luminescence process in the complexes was also discussed in detail.

Supramolecular Terbium-SIP Complex Pillared by 4,4'-Bipyridyl,{[Tb(SIP)(H_2O)_5]_2(bpy)_3(H_2O)}n:Synthesis,Crystal Structure and Photoluminescence

The supramolecular terbium complex, {[Tb（SIP）（H2O）5]2（bpy）3（H2O）}n （NaH2SIP = 5-sulfoisophthalic acid monosodium salt and bpy = 4,4＇-bipyridyl）, has been synthesized by the hydrothermal reaction of Tb4O7 with NaH2SIP and bpy at 165 ℃, and characterized by single-crystal X-ray diffraction, elemental analysis, IR spectrum, powder X-ray diffraction and photoluminescence spectrum. It crystallizes in a monoclinic system, space group C2/c, with a = 30.6840（1）, b = 10.9206（2）, c = 17.4967（3） A, β= 111.931（1）°, V = 5438.65（14） A^3, Z = 4, C46H52N6O25S2Tb2, Mr = 1470.90, Dc = 1.796 g/cm^3, p = 2.747 mm^-1, F（000） = 2928, the final R = 0.0654 and wR = 0.1322 for 3806 observed reflections with I 〉 2σ（I）. In the neutral [Tb（SIP）（H2O）5]2 motif, the Tb（III） ions are linked by the SIP ligands to form a one-dimensional zigzag chain propagating along the c axis. The zigzag chains are linked together by hydrogen bonds and π-π stacking interactions to form a two-dimensional supramolecular framework. The uncoordinated bpy molecules act as pillars to extend the two-dimensional sheets into a distinctive pillared three-dimensional supramolecular structure through O-H...N hydrogen bonds. The photoluminescence of the complex was investigated at room temperature in the solid state.

Tetrameric(Bi4I16)4- Iodobismuthate Templated by 1,ω-Bis（isoquinoline）alkane Cation: Structure,Photoluminescence and Enhanced Thermochromism

Using 1,1?-bis(isoquinoline)-1,4-phenyldimethylenyl(BIQPM2+) cation as template, a new tetrameric(Bi4 I16)4-iodobismuthate-containing hybrid with formula of(BIQPM)2(Bi4 I16)·H2 O(1), has been prepared under solvothermal conditions. The centrosymmetric Bi4-4 I16 tetraanion is constructed from four edge-shared slightly distorted BiI6 octahedrons. Due to the presence of larger conjugated system(isoquinoline ring), strong π···π stacking interactions can be observed. Besides, strong I···I interactions can be monitored and extends the 0-D Bi4 I4-16 cluster to a quasi-1-D chain. The smaller energy gap of 2.13 eV is led by these non-covalent interactions. Its infrared emission might be caused by strong charge transfer between anions and cations. Furthermore, the reversible thermochromic behavior with low chromotropic temperature of 80 ℃ can be observed, whose mechanism was discussed.