Nanostructured gold has attracted significant interest from materials science, chemistry, optics and photonics, and biology due to their extraordinary potential for manipulating visible and near‐infrared light through the excitation of plasmon resonances. However, gold nanostructures are rarely measured experimentally in their plasmonic properties and hardly used for high‐temperature applications because of the inherent instability in mass and shape due to the high surface energy at elevated temperatures. In this work, the first direct observation of thermally excited surface plasmons in gold nanorods at 1100 K is demonstrated. By coupling with an optical fiber in the near‐field, the thermally excited surface plasmons from gold nanorods can be converted into the propagating modes in the optical fiber and experimentally characterized in a remote manner. This fiber‐coupled technique can effectively characterize the near‐field thermoplasmonic emission from gold nanorods. A direct simulation scheme is also developed to quantitively understand the thermal emission from the array of gold nanorods. The experimental work in conjunction with the direct simulation results paves the way of using gold nanostructures as high‐temperature plasmonic nanomaterials, which has important implications in thermal energy conversion, thermal emission control, and chemical sensing.
Due to the increasing desire for nanoscale optoelectronic devices with green light emission capability and high efficiency, ternary III‐N‐based nanorods are extensively studied. Many efforts have been taken on the planar device configuration, which lead to unavoided defects and strains. With selective‐area molecular‐beam epitaxy, new “Russian Doll”‐type InGaN/AlGaN quantum wells (QWs) have been developed, which could largely alleviate this issue. This work combines multiple nanoscale characterization methods and k∙p theory calculations so that the crystalline structure, chemical compositions, strain effects, and light emission properties can be quantitatively correlated and understood. The 3D structure and atomic composition of these QWs are retrieved with transmission electron microscopy and atom probe tomography while their green light emission has been demonstrated with room‐temperature cathodoluminescence experiments. k∙p theory calculations, with the consideration of strain effects, are used to derive the light emission characteristics that are compared with the local measurements. Thus, the structural properties of the newly designed nanorods are quantitatively characterized and the relationship with their outstanding optical properties is described. This combined approach provides an innovative way for analyzing nano‐optical‐devices and new strategies for the structure design of light‐emitting diodes.
more » « less- Award ID(s):
- 1709207
- PAR ID:
- 10456947
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Advanced Optical Materials
- Volume:
- 8
- Issue:
- 17
- ISSN:
- 2195-1071
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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