Synergistic Effects on Second Harmonic Generation of Hybrid CdSe−Au Nanoparticles

Abstract

Hybrid semiconductor-metal nanoparticles exhibit a combination of properties from the disparate components or even, more interestingly, synergetic properties which arise from the coupling between the two materials. In this work, we study the second harmonic generation (SHG) in CdSe-Au hybrid nanoparticles in comparison with their components, using the Hyper-Rayleigh scattering (HRS) method. Possible contribution of symmetry effects was studied by comparing symmetric two-sided gold-tipped CdSe nanodumbbells with asymmetric one-sided quantum dot-Au (QD-Au) hybrids. A simplistic view of a symmetry effect is disproved in this case by the experimental data, which shows an unexpected reduction in the SHG response in both cases, compared to the respective mixtures of Au and CdSe nanoparticles. For CdSe-Au hybrids with a long semiconductor rod segment, we find that the SHG response corresponds to a sum of the contributions from the semiconductor and the metal components. However, for QD-Au and smaller dumbbells, the SHG response is smaller than expected from a simple sum of the contribution from both components. This reduction is assigned to the effects related to the CdSe-Au interfacial region within these hybrids. A first plausible contribution to the reduction is the dephasing induced by the gold, leading to diminished SHG from the CdSe component. This reduced response of the semiconductor component is accompanied by reduced SHG from the gold component which is assigned to a partial change of the surface of the gold once an interface with CdSe is formed. These observations regarding the SHG response manifest the unique properties that arise from the combination of a semiconductor and a metal within one hybrid nanoparticle.

Harmonic nanoparticles: noncentrosymmetric metal oxides for nonlinear optics

“…These previous contributions were explicitly intended for the nanotechnological community, while the purpose here is to review and disseminate the most recent results to the optics community to further stimulate interest for these photonics nanoprobes. The scope of this paper is limited to works published in the last decade on non-fluorescent, noncentrosymmetric, inorganic oxides with dimensions in the 20-200 nm range, purposely excluding investigations on the nonlinear optical response of semiconductor quantum dots and noble metal nanoparticles [11][12][13][14][15]. The following materials will be treated: KNbO 3 , BiFeO 3 (BFO), LiNbO 3 , BaTiO 3 , Fe(IO 3 ) 3 , Ba(BO 2 ) 2 (BBO), KTiOPO 4 (KTP), and ZnO.…”

Anisotropic Gold Nanoparticles: Preparation, Properties, and Applications

“…The Au/Ag core/shell structures have been created either by silver deposition onto AuNDs [82], or by galvanic replacement and reduction [83]. There are other metals for hybrid AuNDs, including CdSe [84], CoPt 3 , FePt and Pt [85].…”

Tunable Plasmon Resonance and Fluorescence of Au/ZnS/CdS Core/Shell Nanorods

“…Metal-semiconductor hetero-nanostructures, which combine the optical properties of plasmonic nano-antennas and lowdimensional semiconductors, have great potential for solar energy conversion, biological applications, and quantum information [1][2][3][4][5][6][7][8][9][10][11]. The interactions between the nanoscalespaced metal and semiconductor components can greatly improve the overall application performance of the heteronanostructures and can even generate new synergetic properties [12][13][14][15][16][17][18][19][20][21][22][23][24][25].…”