Self-aligned epitaxial metal-semiconductor hybrid nanostructures for plasmonics

Abstract

We demonstrate self-alignment of epitaxial Ag nanocrystals on top of low-density near-surface InAs quantum dots (QDs) grown by molecular beam epitaxy. The Ag nanocrystals support a surface plasmon resonance that can be tuned to the emission wavelength of the QDs. Photoluminescence measurements of such hybrid metal-semiconductor nanostructures reveal large enhancement of the emission intensity. Our concept of epitaxial self-alignment enables the integration of plasmonic functionality with electronic and photonic semiconductor devices operating down to the single QD level.

Site-controlled Ag nanocrystals grown by molecular beam epitaxy—Towards plasmonic integration technology

“…17 The appearance of sharp diffraction spots, i.e. bulk transmission diffraction patterns marked by the red circles, is evidence for the epitaxial growth of the Ag NCs on (100) GaAs.…”

“…According to our previous studies of the optical properties of Ag NCs on GaAs, the NCs of the size obtained in the holes support LSPR in the desired nearinfrared wavelength range coinciding with the QD emission wavelength. 17 Due to the relatively large area of the hole sidewalls as compared to the average base size of the Ag NCs, the demonstrated positional accuracy of the ordering has a significant random component. This issue can be solved by decreasing the hole size, thus decreasing the sidewall area available for preferential nucleation of the Ag NCs.…”

Epitaxial self-alignment: A new route to hybrid active plasmonic nanostructures

“…PL measurements revealed clear intensity enhancements which were attributed to SPR enhanced emission and absorption. The superior control of size, density, and position demonstrated here for epitaxial metal nanocrystals is highly relevant to exploit plasmonic effects for a much wider range of applications than discussed so far, including sensing [32,33], spectroscopy [34], imaging [35], solar energy conversion [36,37], nanophotonic circuits [38,39], and many others. It should be emphasized here that metal nanostructures when they are single-crystalline exhibit the best plasmonic properties [40].…”

Theoretical Investigation of Optical Detection and Recognition of Single Biological Molecules Using Coherent Dynamics of Exciton-Plasmon Coupling

“…23-25 Some recent reports have also shown the possibility of fabrication of MNPs inside epitaxial structures, 26 formation of epitaxial QDs very close to the surface, 27 and deposition of Ag MNPs close to the epitaxially grown QDs. 28 These techniques can support exciton-plasmon coupling, which is needed for practical implementation of the results presented in this paper. Note also that coherent coupling of excitons and plasmons is scaled by the polarization dephasing rate and transition energy of the QDs, R , laser intensity, and type or shapes of the MNPs.…”