The Experts below are selected from a list of 33483 Experts worldwide ranked by ideXlab platform

Jianggao Mao - One of the best experts on this subject based on the ideXlab platform.

Jingui Qin - One of the best experts on this subject based on the ideXlab platform.

  • pb3 seo3 br4 a new nonlinear optical Material with enhanced shg response designed via an ion substitution strategy
    Dalton Transactions, 2017
    Co-Authors: Xiaoxiao Wang, Hongming Liu, Zheshuai Lin, Xianggao Meng, Xingguo Chen, Xingxing Jiang, Lei Yang, Jingui Qin
    Abstract:

    Using an ion-substitution strategy, herein, a new Polar Material, Pb3(SeO3)Br4, with a greatly enhanced SHG response has been successfully designed and synthesized through a hydrothermal reaction. Pb3(SeO3)Br4 crystallizes in the NCS space group P212121 and consists of a three-dimensional framework formed by interconnecting one-dimensional chains, with a good thermal stability up to 230 °C. This compound exhibits a phase-matchable SHG response as strong as that of KH2PO4 (KDP) and a relatively wide mid-infrared (mid-IR) transparent window. Moreover, the optical band gap of Pb3(SeO3)Br4 reaches about 3.35 eV, thus leading to a high laser damage threshold (LDT) of 67 MW cm-2, which is over 12 times that of AgGaS2 (<5 MW cm-2) measured under the same condition. All these findings suggest that Pb3(SeO3)Br4 would be a candidate for an NLO Material in the mid-IR region.

  • rb2seocl4 h2o a Polar Material among the alkali metal selenite halides with a strong shg response
    Dalton Transactions, 2016
    Co-Authors: Hongming Liu, Lei Kang, Zheshuai Lin, Xianggao Meng, Xingguo Chen, Jingui Qin
    Abstract:

    An alkali metal selenite chloride, Rb2SeOCl4·H2O, has been hydrothermally synthesized and structurally characterized. It is the first example of an alkali metal selenite halide in the literature. The compound crystallizes in the noncentrosymmetric (NCS) space group, Cmc21(36), of the orthorhombic system with a = 10.342(3) A, b = 10.124(3) A, c = 9.158(3) A, and α = β = γ = 90°. The anionic [SeOCl4]2− groups are arranged in the crystal in nearly the same direction, giving rise to a relatively large macroscopic dipole moment, causing the compound to display second harmonic generation (SHG) eight times as strong as that of KDP, measured using the Kurtz–Perry method on powders. First-principle density functional theory (DFT) calculations were carried out to interpret the relationship between the crystal structure and properties.

U K Mishra - One of the best experts on this subject based on the ideXlab platform.

  • interface states at the sin algan interface on gan heterojunctions for ga and n Polar Material
    Journal of Applied Physics, 2012
    Co-Authors: Ramya Yeluri, Brian L Swenson, U K Mishra
    Abstract:

    Dielectric passivation is important to improve the stability and reliability of gallium nitride based semiconductor devices. We need to characterize various dielectrics and their interfaces to nitrides accurately to be able to exploit the benefits efficiently. Earlier, B. L. Swenson and U. K. Mishra [J. Appl. Phys. 106, 064902 (2009)] have detailed a photo-assisted high frequency CV characterization technique for the Ga-Polar SiN/GaN interface that gives an accurate value of interface state density (Dit) across the bandgap of the dielectric. In this work, we extend the technique to study the interface states at the SiN/AlGaN interface on GaN for Ga and N Polar Material. This simulates the AlGaN/GaN HEMT structure. A MIS-type structure comprised of a metal on SiN on an AlGaN/GaN heterojunction was used for the study. For a structure with 1 nm AlGaN interlayer, a peak interface state density of 2.8 × 1012 cm−2 eV−1 was measured. For Ga Polar devices, the measured Dit decreases with increasing AlGaN thicknes...

  • interface states at the sin algan interface on gan heterojunctions for ga and n Polar Material
    Journal of Applied Physics, 2012
    Co-Authors: Ramya Yeluri, Brian L Swenson, U K Mishra
    Abstract:

    Dielectric passivation is important to improve the stability and reliability of gallium nitride based semiconductor devices. We need to characterize various dielectrics and their interfaces to nitrides accurately to be able to exploit the benefits efficiently. Earlier, B. L. Swenson and U. K. Mishra [J. Appl. Phys. 106, 064902 (2009)] have detailed a photo-assisted high frequency CV characterization technique for the Ga-Polar SiN/GaN interface that gives an accurate value of interface state density (Dit) across the bandgap of the dielectric. In this work, we extend the technique to study the interface states at the SiN/AlGaN interface on GaN for Ga and N Polar Material. This simulates the AlGaN/GaN HEMT structure. A MIS-type structure comprised of a metal on SiN on an AlGaN/GaN heterojunction was used for the study. For a structure with 1 nm AlGaN interlayer, a peak interface state density of 2.8 × 1012 cm−2 eV−1 was measured. For Ga Polar devices, the measured Dit decreases with increasing AlGaN thickness. In the N-Polar case, the measured Dit increases with increasing AlGaN thickness. The variations of measured Dit with AlGaN thickness, in both cases, can be explained by screening from the accumulation charge at the AlGaN/GaN interface.

Dongmei Wang - One of the best experts on this subject based on the ideXlab platform.

James M Rondinelli - One of the best experts on this subject based on the ideXlab platform.

  • designing a deep ultraviolet nonlinear optical Material with a large second harmonic generation response
    Journal of the American Chemical Society, 2013
    Co-Authors: Hongping Wu, Kenneth R. Poeppelmeier, Hongwei Yu, Xin Su, James M Rondinelli
    Abstract:

    The generation of intense coherent deep-UV light from nonlinear optical Materials is crucial to applications ranging from semiconductor photolithography and laser micromachining to photochemical synthesis. However, few Materials with large second harmonic generation (SHG) and a short UV-cutoff edge are effective down to 200 nm. A notable exception is KBe2BO3F2, which is obtained from a solid-state reaction of highly toxic beryllium oxide powders. We designed and synthesized a benign Polar Material, Ba4B11O20F, that satisfies these requirements and exhibits the largest SHG response in known borates containing neither lone-pair-active anions nor second-order Jahn-Teller-active transition metals. We developed a microscopic model to explain the enhancement, which is unexpected on the basis of conventional anionic group theory arguments. Crystal engineering of atomic displacements along the Polar axis, which are difficult to attribute to or identify within unique anionic moieties, and greater cation Polarizabilities are critical to the design of next-generation SHG Materials.