| 1. |
- Luo, Ziyu, et al.
(author)
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An Efficient Deep-Subwavelength Second Harmonic Nanoantenna Based on Surface Plasmon-Coupled Dilute Nitride GaNP Nanowires
- 2021
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In: Nano Letters. - : AMER CHEMICAL SOC. - 1530-6984 .- 1530-6992. ; 21:8, s. 3426-3434
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Journal article (peer-reviewed)abstract
- High-index semiconductor nanoantennae represent a powerful platform for nonlinear photon generation. Devices with reduced footprints are pivotal for higher integration capacity and energy efficiency in photonic integrated circuitry (PIC). Here, we report on a deep subwavelength nonlinear antenna based on dilute nitride GaNP nanowires (NWs), whose second harmonic generation (SHG) shows a 5-fold increase by incorporating similar to 0.45% of nitrogen (N), in comparison with GaP counterpart. Further integrating with a gold (Au) thin film-based hybrid cavity achieves a significantly boosted SHG output by a factor of similar to 380, with a nonlinear conversion efficiency up to 9.4 x 10(-6) W-1. In addition, high-density zinc blende (ZB) twin phases were found to tailor the nonlinear radiation profile via dipolar interference, resulting in a highly symmetric polarimetric pattern well-suited for coupling with polarization nano-optics. Our results manifest dilute nitride nanoantenna as promising building blocks for future chip-based nonlinear photonic technology.
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| 2. |
- Paul, Neelima, et al.
(author)
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Real-time observation of nucleation and growth of Au on CdSe quantum dot templates
- 2021
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In: Scientific Reports. - : Springer Nature. - 2045-2322. ; 11:1
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Journal article (peer-reviewed)abstract
- Semiconductor quantum dot (QD) arrays can be useful for optical devices such as lasers, solar cells and light-emitting diodes. As the size distribution influences the band-gap, it is worthwhile to investigate QDs prepared using different solvents because each of them could influence the overall morphology differently, depending on the ligand network around individual QDs. Here, we follow the nucleation and growth of gold (Au) on CdSe QD arrays to investigate the influence of surface ligands and thereby realized interparticle distance between QDs on Au growth behaviour. We particularly emphasize on the monolayer stage as the Au decoration on individual QDs is expected at this stage. Therefore, we sputter-deposit Au on each QD array to investigate the morphological evolution in real-time using time-resolved grazing-incidence small-angle X-ray scattering (GISAXS). The growth kinetics - independent of the template - signifies that the observed template-mediated nucleation is limited only to the very first few monolayers. Delicate changes in the Au growth morphology are seen in the immediate steps following the initial replicated decoration of the QD arrays. This is followed by a subsequent clustering and finally a complete Au coverage of the QD arrays.
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