红外Ga_2S_3–Sb_2S_3硫系玻璃的热稳定性及光学性能

采用真空熔融淬冷法制备Ga_xSb_(40–x)S_(60)硫系玻璃样品,并通过Archimedes法、X射线衍射、热膨胀系数分析、可见/近红外光谱吸收度与透过率、中远红外光谱透过率以及Raman散射光谱等研究了硫系玻璃样品的结构、热稳定性和光学性能。结果表明:随着Ga含量的增加,玻璃密度逐渐下降,玻璃转变温度逐渐提高,热膨胀系数不断减小,表明玻璃具有良好的热稳定性;玻璃的可见/近红外短波截止边均发生蓝移,光学带隙增大,而且保持了良好的红外透过率,其较宽的红外透过范围(0.8~14.0μm),涵盖了目前3大主要通信波段和热红外波段,Ga–Sb–S玻璃已成为极具前景的红外材料。Ga含量增加促进[GaS_4]四面体的形成,减少[SbS_3]三角锥的比例,归纳了该类硫系玻璃的光学性质与结构的依赖关系。     

远红外Ge-Te-Se硫系玻璃与光纤(英文)

采用传统的熔融–淬冷法制备了系列GexTe65Se(35–x)(x=20,22,23,24;摩尔分数,x%)Te基硫系玻璃。利用X射线衍射、差示扫描量热分析、分光光度计、红外光谱仪等设备研究了玻璃的性能。这些玻璃具有良好的热稳定性和红外透过性能。组分为Ge23Te65Se12,Ge24Te65Se11的玻璃的差示扫描量热曲线中没有出现析晶峰,表明玻璃具有良好的抗析晶性能。组分为Ge24Te65Se11的玻璃的转变温度Tg最高,达到了188℃。这些玻璃样品的红外透过范围都很宽,从近红外的1.8μm到远红外的18μm。通过在玻璃的制备工艺中引入蒸馏提纯工艺可以有效减弱杂质吸收峰对玻璃红外透过性能的影响。最后,选用Ge23Te65Se12玻璃作为包层,Ge24Te65Se11玻璃作为纤芯,采用棒管法完成了具有纤芯包层结构的Ge-Te-Se红外光纤的拉制。     

GeS2-Ga2S3-PbCl2玻璃的三阶非线性光学特性

采用熔融-淬冷法制备了(100-x)(0.8GeS2-0.2Ga2S3)-xPbCl2(x=0,5,10,15,摩尔分数)系列硫卤玻璃,测试了样品的密度、可见-中远红外的透过性以及样品的折射率,并且根据Z扫描测试原理测试了飞秒脉冲下,样品在800 nm波长下的三阶非线性光学特性.结果表明:非线性折射率n2和非线性吸收系...     

GeS2-Ga2S3-PbCl2玻璃的三阶非线性光学特性

采用熔融-淬冷法制备了(100-x)(0.8GeS2-0.2Ga2S3)-xPbCl2(x=0,5,10,15,摩尔分数)系列硫卤玻璃,测试了样品的密度、可见-中远红外的透过性以及样品的折射率,并且根据Z扫描测试原理测试了飞秒脉冲下,样品在800 nm波长下的三阶非线性光学特性.结果表明:非线性折射率n2和非线性吸收系数β均随着PbCl2含量的增加而增大,特别是x=15的样品的非线性折射率n2=2.812×10-17m2/W,非线性吸收系数β=4.298×10-11m/W,较传统无重金属参杂硫系玻璃的三阶非线性性能明显提高.     

In含量对Ge-In-Se薄膜光学特性的影响(英文)

采用磁控溅射法制备了Ge-In-Se硫系薄膜,利用X射线衍射、可见-近红外吸收光谱和Raman光谱分析等技术对Ge-In-Se硫系薄膜的相态、结构和光学特性进行了研究和分析。结果表明:该Ge-In-Se薄膜具有良好的非晶特性。Raman光谱分析表明:[GeSe4]四面体Ge—Se键的高频振动模式是该薄膜的主要振动模式之一,且Ge—Se键的振动强度随着In含量的增加而减小;当In的含量达到13.87%(摩尔分数)时,[GeSe4]四面体消失,而[InSe4]四面体的对称伸缩振动模式成为了主要振动模式。采用Swanepoel方法和经典Tauc方程计算发现:随着In含量增加,该薄膜的短波吸收限红移,折射率逐渐增大,光学带隙逐渐减小。     

新型硫系玻璃热电极化的倍频效应

为探索优良非线性光学玻璃材料,研究了不同磷族元素掺入对GeS2-Ga2S3玻璃结构和性能的影响.利用传统的熔融淬冷技术,制备了0.8GeS2·0.1Ga2S3·0.1X2S3(X=P,As,Sb)3种硫系玻璃.差热分析表明:所制备的3种硫系玻璃的晶化温度和转变温度之差均大于100K,具有较好的成玻性能.Raman光谱、远红外光谱、可见-近红外光谱、Maker条纹等方法对3种硫系玻璃的结构和性能进行了分析.结果表明:玻璃内部存在较多的多面体单元可以导致玻璃在热电极化后出现较大的二阶非线性光学性能,玻璃在可见光波段透过率的不同将会导致在Maker条纹仪记录倍频光强度时出现反射和透射的倍频效应.     

新型GeSe2-Ga2Se3-KI系统硫卤玻璃形成的研究

开发了有高含量碱金属离子的新型硫化物玻璃.合成了GeSe2-Ga2Se3-KI系统的玻璃样品.研究了该系统的玻璃形成区并用孤对电子理论进行了解释.讨论了Ga2Se3和KI对玻璃形成能力的影响.给出了该系统玻璃的密度、特性温度、Raman和可见一红外光谱等.实验结果表明:该系统具有较广的玻璃形成区,某些组成,如摩尔组成为50 GeSe2 25Ga2Se3 25KI的样品具有良好的热学和光学性质,其表征热稳定性的特征温度差大于120K,玻璃透光范围从590nm到14.2μm.     

CsCl对GeS_2-Sb_2S_3硫系玻璃光学及析晶特性的影响

通过熔融-淬冷法制备了(100-x)(0.9GeS2-0.1Sb2S3.)-xCsCl(x=5,10,15,20,以摩尔计)系列硫卤玻璃.测试了样品的折射率和吸收光谱.根据Tauc方程计算了间接允许光学带隙和直接允许光学带隙.通过差热分析对微晶玻璃析晶动力学进行了研究.利用析晶活化能(E)和频率因子(v),并结合动力学因素和热力学因素分析了玻璃的稳定性.结果表明:随着CsCl含鼍的增加,样品的线性折射率变小,短波截止波长蓝移,光学带隙逐渐增大,玻璃稳定性变差:85(0.9GeS2-0.1Sb2S3)15CsCl玻璃样品较适合制备透明的微晶玻璃,可用于研究硫系基质玻璃与微晶玻璃之间的三阶非线性效应.     

(Ge_(0.42)S_(0.58))_(100-x)(Sb_(0.4)S_(0.6))_x玻璃的Raman谱

测量了硫系玻璃(Ge_(0.42)S_(0.58))_(100-x)(Sb_(0.4)S_(0.6))_x块样和薄膜的Raman光谱随组成x的变化。 随着x增加,380cm~(-1)处的蜂(x=0时)的中心波数移向低波数方向,这是由于Ge—S键数增加,五种分子团数的比例发生变化所引起的。x=30时,峰的中心波数约为340cm~(-1)。x继续增大,该玻璃系的Raman谱倾向于类似Sb_2S_3的Raman谱。x=45时,170cm~(-1)处的峰(对应于S_2Sb-SbS_2分子团的振动)达到最大。 块样的Raman谱基本上与薄膜的Raman谱相类似,表明组成块样和薄膜的分子团种类和它们间的比例关系大体相同。     

新型远红外Ge–Ga–Te–CsCl硫系玻璃的光学特性（英文）

利用传统的熔融-淬冷法制备了一系列新型的掺杂卤化物CsCl的Te基玻璃。通过差示扫描量热仪和Fourier红外光谱仪等测试了玻璃样品的热学及光学性能。结果表明,该玻璃具有良好的热学及光学性质。(Ge_(15)Ga_(10)Te_(75))_(80)(CsCl)_(20)玻璃样品的析晶温度T_x和转变温度T_g的差值△T最大,达到了118℃。随着CsCl含量的增加,玻璃的密度随之减小,但是吸收截止边先发生蓝移然后再向长波方向移动,其原因在于玻璃的结构及其均匀性的改变。此外,光学带隙的最大值仅为0.721 eV。通过提纯消除了Ge-Ga-Te-CsCl玻璃中杂质的影响,并且提纯后的玻璃在2-20μm波长范围内有着平坦的红外光学窗口。     

Thermal and optical properties of La2O3–Ga2O3– (Nb2O5 or Ta2O5) ternary glasses

La₂O₃–Ga₂O₃–M₂O₅ (M = Nb or Ta) ternary glasses were fabricated using an aerodynamic levitation technique, and their glass‐forming regions and thermal and optical properties were investigated. Incorporation of adequate amounts of Nb₂O₅ and Ta₂O₅ drastically improved the thermal stabilities of the glasses against crystallization. Optical transmittance measurements revealed that all the glasses were transparent over a wide wavelength range from the ultraviolet to the mid‐infrared. The refractive indices of the glasses increased and the Abbe number decreased upon substituting Ga₂O₃ with Nb₂O₅, and the decrease in the Abbe number was significantly suppressed when Ta₂O₅ was incorporated into the glass. As a result, excellent compatibility between high refractive index and lower wavelength dispersion was realized in La₂O₃–Ga₂O₃–Ta₂O₅ glasses. Analysis based on the single‐oscillator Drude–Voigt model provided more systematical information and revealed that this compatibility was due to an increase in the electron density of the glass.     

The tri-emitting phosphate phosphors SrIn2(P2O7)2: Tm,Dy, Eu for ratiometric optical thermometer

Developing new phosphors used for ratiometric optical thermometers has attracted broad attention recently. According to the recent research, the phosphate SrIn₂(P₂O₇)₂ with regard to the structural rigidity has been adopted as the host of Tm and Dy activators behaving the super-stable white emission. Herein, Tm, Dy, Eu tri-doped phosphors were prepared to investigate the interaction of three different activators and their coupling sensitivity to temperature. Based on concentration control and energy transfer among three activators, the tunable emission, including the idea warm white, has been obtained. In the case of increasing temperature, the emission intensities of Dy³⁺ and Eu³⁺ partially decrease, whereas the Tm³⁺ fluorescence extremely keeps increasing to 155.4% of 473 K compared with that of room temperature. This phenomenon can be defined the negative thermal-quenching. It is believed that the back energy transfer (BET) from Dy³⁺ and that from Eu³⁺ to Tm³⁺ help the negative thermal-quenching of Tm³⁺ to a certain extent. Both cation occupation and structural rigidity obviously affect the BET efficiency. In the new phosphors, the fluorescence intensity ratios of Tm³⁺ and Eu³⁺ (blue/red) and (blue/orange) of Tm³⁺/Dy³⁺ are closely related to temperature and vary linearly over a wide temperature range, which can be regarded as an important index of temperature sensor. The SI_1.92P: T_0.01D_0.01E_0.06 shows excellent temperature sensitivity and recyclability. The current results show that SrIn₂(P₂O₇)₂: Tm, Dy, Eu phosphors can be regarded as candidate materials for optical thermometry.     

The study of optical and photodielectric properties of polymethyl methacrylate and tris-(8-hydroxy-quinoline) aluminum (Alq3) composites

Polymer composite films of tris-(8-hydroxy-quinoline) aluminum (Alq3) and polymethyl methacrylate (PMMA) at two different concentrations were investigated. Dielectric properties of the samples were measured in broad frequency range and results show an increase in specific conductance and susceptance by adding Alq3 in PMMA. Changes in dielectric spectra caused by irradiation of the samples with LED lamps at different wavelengths were also recorded. The samples were examined by UV–Vis and Fourier transform infrared spectroscopy. The interaction between Alq3 and the polymer matrix was observed in the photoluminescence spectroscopy spectra. The doping of the PMMA with different concentrations of the Alq3 leads to the unique photodielectric properties of the resulting composite, and that is the main result of this study. Due to its interesting optical and photodielectric properties, PMMA/Alq3 film may find application in solar cells and optoelectronics.     

Synthesis and up-conversion of Er3+ and Yb3+ Co-doped LiY(MoO4)2@SiO2 for optical thermometry applications

Non-contact temperature sensors based on the fluorescence intensity ratio (FIR) have been widely investigated owing to their high sensitivity and reliable real-time monitoring. Herein, the SiO₂-coated LiY(MoO₄)₂@SiO₂:Er³⁺,Yb³⁺ phosphor was investigated as an optical thermometry material, which was synthesized using the conventional solid state reaction and coated by a facile wet chemical route. The effect of surface modification on FIR was systematically characterized by structural analyses and spectral measurements and the temperature-dependent up-conversion FIR was investigated from 303 to 603 K under a 980 nm laser excitation. The results showed that the FIR value was thermally stable and the SiO₂ coating led to a higher FIR sensitivity as well as a higher saturation threshold. This work would pave a way to design interesting optical thermometry materials in up-conversion phosphors with better properties.     

High-refractive index polythiourethane resin based on 2,3-bis((2-mercaptoethyl) thio)-1-propanethiol and 1,3-bis(isocyanantomethyl) cyclohexane using tertiary amine catalyst

High-refractive index (RI) polythiourethane (PTU) resin with good thermal, optical, and mechanical properties was synthesized via thiol-isocynanate click reaction of 2,3-bis((2-mercaptoethyl)thio)-1-propanethiol and 1,3-bis(isocyanantomethyl) cyclohexane using a new tertiary amine catalyst N,N,N′,N′-tetramethyl-1,4-diaminobutane (TMDB). Curing behavior of PTU resin was studied by dynamic differential scanning calorimetry (DSC) technique. Curing technology parameters were optimized by combined use of DSC and fourier transform infrared spectrometry (FTIR). The results indicate that TMDB exhibits higher catalytic activity than commonly used dibutyltin dichloride (DBTC). The Kissinger apparent activation energies at a dosage of 150 ppm TMDB and 150 ppm DBTC are 31.7 and 43.2 kJ mol⁻¹, respectively. PTU resin with a full conversion of thiol and isocynanate was prepared, which exhibited better thermal, optical, and mechanical properties than that reported previously. The resin displays a glass transition temperature of 102 and 129°C determined by DSC and dynamic thermomechanical analysis (DMA), respectively, a 5% weight loss temperature of 279°C in nitrogen, a light transmittance of 87% in the wavelength range of 410–900 nm, a water contact angle of 100°, a high-RI of 1.617, and an Abbe number of 38. The resin was successfully applied in ophthalmic lenses.     

White‐light‐emitting hybrid film from fluorescent hyperbranched poly(amido amine)

The flexible, strong, and tough white‐light‐emitting (WLE) hybrid films are highly demanded in large‐scale displays, including TV sets, monitors, and electronic interactive devices. In this work, a kind of WLE hybrid film was fabricated from hyperbranched poly(amido amine) (HPAMAM) and nanoclay with the incorporation of riboflavin (VB₂) and rhodamine B (RhB). The fluorescence emission of HPAMAM was partially absorbed and effectively transferred into green and red color, which combined into a bright white light with the residue blue fluorescence. Due to the alignment of nanoclay inside the HPAMAM matrix, in addition to the strong interaction among the HPAMAM molecules and that between HPAMAM and nanoclay, this hybrid film shows to be strong and tough. The mechanical strength is about 20 MPa and the elongation is about 30%. It is convinced that this hybrid film is promising in flexible large‐scale displays. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46015.     

Stretchable photochromic hydrous TiO2-embedded glycerol-poly(dimethylsiloxane) film for rewritable information storage

Photoreversible, color-changing films have great potential in various optical applications. In this study, we developed a photochromic film by embedding droplets of metatitanic acid (hydrous TiO₂) and glycerol in commercially available poly(dimethylsiloxane) (PDMS) silicone elastomers. Benefiting from the electron–hole pair scavenging abilities of glycerol, the resulting film exhibited rapid photoresponse, high photoreversible stability, excellent antiaging capability, and remarkable stretchability. The degree of color changes upon ultraviolet (UV) irradiation was effectively controlled by adjusting both the concentration of hydrous TiO₂ (1–20 wt%) and UV irradiation time (5–30 min), thereby increasing total color-changing ability (ΔE). High-resolution patterns could be repetitively printed, erased, and rewritten (≥20 times) with no significant loss of clarity. After a 30-day exposure to ambient air, there were no significant aging effects in the photochromic ability of the films, thus demonstrating promising potential as rewritable films for information storage.     

Electron spin resonance and optical studies of poly(methylmethacrylate) doped with CuCl2

Poly(methyl methacrylate) doped with CuCl₂ was prepared and its electron spin resonance (ESR) spectra and optical properties were studied. The ESR spectra can be accounted for by the presence of two radicals: R_a and R_b. FTIR spectroscopy reveals that there is no main difference of the spectra due to the addition of CuCl₂. The structural modifications are identified by investigating the doping level dependence of the peak heights of certain IR absorption peaks. The optical absorption, transmittance, and reflectance measurements were performed for prepared samples. The doping level (W) dependence on the g‐factor (g), asymmetry factor (A), peak‐to‐peak separation (ΔH_pp), spin concentration (N), optical energy gap (E_opt), Urbach energy (E_u), refractive index (n), average oscillator wavelength (λ_o), and average oscillator strength (S_o) were estimated. It was found that these parameters are changed with doping level. These changes suggest high sensitivity of these films to doping that would suggest the applicability in magnetic and/or optical devices. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Phase formation and spectral evolution of (Sr,Ba)2Si(O,N)4:Eu2+ phosphors

Sr_2‐xBa_xSi(O,N)₄:Eu²⁺ (SB_xSON:Eu²⁺) oxynitridosilicate phosphors were prepared via incorporation of N^3?, Eu²⁺, and Ba²⁺ ions into Sr₂SiO₄ (SSO) lattices. X‐ray diffraction patterns of the prepared powders revealed that SB_xSON:Eu²⁺ was a solid‐solution form of SSO. An increase in x values caused a phase transition and an expansion of the unit cell. The photoluminescence excitation (PLE) spectra of SB_xSON:Eu²⁺ were broad, covering the ultraviolet range to the visible range. Corresponding PL emission spectra strongly depended on the excitation wavelengths and consisted of two emission bands, one in the green‐blue region (A‐band) and the other in the red region (B‐band), which were assigned to Eu(I) and Eu(II), respectively. The B‐band resulted from a dramatic red‐shift of the green emission band assigned to Eu(II) of SSO:Eu²⁺, revealing that the nitridation process preferentially affected the Eu(II) sites. This behavior was explained by crystal field splitting, the fluorescence decay time, and thermal quenching. The Ba²⁺ substitution caused evolution of the PL spectra, and its effects on the spectra were discussed under consideration of ionic size and covalence.     

Effect of pressure on mechanical and optical properties of ThO2 and PuO2

We have used DFT + U with spin–orbit coupling to understand the effect of pressure on the mechanical and optical properties of ThO₂ and PuO₂. Both the compounds are mechanically stable in a cubic and an orthorhombic structure. The cubic AnO₂ has higher elastic constants and Bader charges on each atom than the orthorhombic AnO₂. With an increase in pressure on cubic AnO₂, elastic modulus increases for both the structures. Bader charge on AnO₂ and magnetic moment of PuO₂ decrease with an increase in pressure for cubic structure. The static refractive index and static dielectric function are higher for PuO₂ in both the cubic and orthorhombic structures as compared to that in ThO₂. The mechanical and optical properties drawn comply with the experimental outcomes.