The Experts below are selected from a list of 309 Experts worldwide ranked by ideXlab platform

Richard Berndt - One of the best experts on this subject based on the ideXlab platform.

  • Light Emission from Na/Cu(111) induced by a scanning tunneling microscope
    Physical Review B, 2002
    Co-Authors: Peter Johansson, Germar Hoffmann, Richard Berndt
    Abstract:

    Measurements of Light Emission from a scanning tunneling microscope probing a Na overlayer on the (111) surface of Cu are reported along with the results of a model calculation that essentially agree with the experimental ones. The observed Light-Emission spectra show two characteristic features depending on the bias voltage. When the bias voltage is smaller than the energy of the second quantum well state formed outside the Na overlayer the Light Emission is due to a plasmon-mediated process, while for larger biases Light Emission is mainly caused by quantum well transitions between the two levels.

Qihuang Gong - One of the best experts on this subject based on the ideXlab platform.

  • Light Emission from Plasmonic Nanostructures Enhanced with Fluorescent Nanodiamonds.
    Scientific reports, 2018
    Co-Authors: Jingyi Zhao, Yuqing Cheng, Te Wen, Hongming Shen, Yuen Yung Hui, Huan-cheng Chang, Qihuang Gong
    Abstract:

    In the surface-enhanced fluorescence (SEF) process, it is well known that the plasmonic nanostructure can enhance the Light Emission of fluorescent emitters. With the help of atomic force microscopy, a hybrid system consisting of a fluorescent nanodiamond and a gold nanoparticle was assembled step-by-step for in situ optical measurements. We demonstrate that fluorescent emitters can also enhance the Light Emission from gold nanoparticles which is judged through the intrinsic anti-Stokes Emission owing to the nanostructures. The Light Emission intensity, spectral shape, and lifetime of the hybrid system were dependent on the coupling configuration. The interaction between gold nanoparticles and fluorescent emitter was modelled based on the concept of a quantised optical cavity by considering the nanodiamond and the nanoparticle as a two-level energy system and a nanoresonator, respectively. The theoretical calculations reveal that the dielectric antenna effect can enhance the local field felt by the nanoparticle, which contributes more to the Light Emission enhancement of the nanoparticles rather than the plasmonic coupling effect. The findings reveal that the SEF is a mutually enhancing process. This suggests the hybrid system should be considered as an entity to analyse and optimise surface-enhanced spectroscopy.

  • Enhanced Light Emission from Plasmonic Nanostructures by Molecules
    Journal of Physical Chemistry C, 2017
    Co-Authors: Yuqing Cheng, Te Wen, Jingyi Zhao, Qihuang Gong
    Abstract:

    Light Emission from plasmonic nanostructures can be enhanced by accompanying molecular Raman scattering during surface-enhanced Raman scattering (SERS). The interaction between the nanostructure and the molecule was modeled based on the concept of quantized optical cavity. We found that the plasmonic nanostructures can elastically scatter the energy coupling from the molecules, resulting in significantly enhanced molecule Raman scattering. Meanwhile, part of the coupling energy was inelastically radiated through plasmon Emission, resulting in a sLight enhancement in background Emission. By comparing a single nanoparticle experiment and theoretical calculations, we reveal that the Light Emission enhancement from the nanostructures is ascribed mainly to the increase in local field felt by the nanostructures. Because the “hot spot” resulting from the nanostructures can strongly polarize the molecules, the induced field of the polarized molecules influences the local field in turn. These findings contribute t...

Alan J. Heeger - One of the best experts on this subject based on the ideXlab platform.

  • visible Light Emission from semiconducting polymer diodes
    Applied Physics Letters, 1991
    Co-Authors: David Braun, Alan J. Heeger
    Abstract:

    We report visible Light Emission from Shottky diodes made from semiconducting polymers, confirming the discovery by the Cambridge group [Nature 347, 539 (1990)]. Our results demonstrate that Light‐emitting diodes can be fabricated by casting the polymer film from solution with no subsequent processing or heat treatment required. Electrical characterization reveals diode behavior with rectification ratios greater than 104. We propose that tunneling of electrons from the recitifying metal contact into the gap states of the positive polaron majority carriers dominates current flow and provides the mechanism for Light Emission.

Peter Johansson - One of the best experts on this subject based on the ideXlab platform.

  • Light Emission from Na/Cu(111) induced by a scanning tunneling microscope
    Physical Review B, 2002
    Co-Authors: Peter Johansson, Germar Hoffmann, Richard Berndt
    Abstract:

    Measurements of Light Emission from a scanning tunneling microscope probing a Na overlayer on the (111) surface of Cu are reported along with the results of a model calculation that essentially agree with the experimental ones. The observed Light-Emission spectra show two characteristic features depending on the bias voltage. When the bias voltage is smaller than the energy of the second quantum well state formed outside the Na overlayer the Light Emission is due to a plasmon-mediated process, while for larger biases Light Emission is mainly caused by quantum well transitions between the two levels.

Jurriaan Schmitz - One of the best experts on this subject based on the ideXlab platform.

  • Increased Light Emission by geometrical changes in Si LEDs
    8th IEEE International Conference on Group IV Photonics, 2011
    Co-Authors: V. Puliyankot, G. Piccolo, Raymond J. E. Hueting, Anco Heringa, Alexeij Y. Kovalgin, Jurriaan Schmitz
    Abstract:

    This paper demonstrates increased Light Emission in Si p-i-n Light emitting diodes (LEDs) by changing the geometry of the device. The theory behind this, the device fabrication, electrical and optical characteristics are also presented. Reducing the injector size, decreases the diffusion current as shown by IV measurements and simulations. As a result, for a particular on- current the pn-product and hence Light increases inside the active region for the new devices. The electroluminescence (EL) intensity measurements show an enhanced Light Emission by more than a factor of four.

  • The effect of dislocation loops on the Light Emission of silicon LEDs
    IEEE Electron Device Letters, 2006
    Co-Authors: T. Hoang, P. Leminh, Jisk Holleman, Jurriaan Schmitz
    Abstract:

    Remarkably strong infrared Light Emission was recently observed from silicon p/sup +/-n diodes. In several publications a causal relation is proposed between the larger-than-expected Light intensity and the existence of lattice damage around the junction. In this letter, we present direct experimental evidence that lattice damage is in fact detrimental to the efficiency of Light Emission of silicon LEDs. The experiments call for a revision of the explanation for strong Light Emission in this type of devices.

  • The effect of dislocation loops on the Light Emission of silicon LEDs
    Proceedings of 35th European Solid-State Device Research Conference 2005. ESSDERC 2005., 1
    Co-Authors: T. Hoang, P. Leminh, Jisk Holleman, Jurriaan Schmitz
    Abstract:

    Recently, different and apparently contradicting results were published regarding the influence of crystal defects on the Light Emission efficiency of silicon LEDs at room temperature (Wai Lek Ng). In this paper we report our results on Light Emission of silicon p/sup +/n diodes with various defect engineering approaches. The p/sup +/ region was formed either by ion implantation or by diffusion; and optionally, additional lattice damage was created by silicon ion implantation. The experiments clearly indicate that lattice defects have a detrimental effect on Light Emission, contrary to the results published in recent years.