Enhancement of photoluminescence from silicon nanocrystals by metal nanostructures made by nanosphere lithography

Abstract

The effect of metal nanostructures prepared by nanosphere lithography on photoluminescence ͑PL͒ properties of silicon nanocrystals ͑Si-ncs͒ is studied. By placing Ag nanotriangles or Au nanovoids on SiO 2 films containing Si-ncs, the PL intensity is enhanced. For the sample having Ag nanotriangles, the largest PL enhancement is obtained when the excitation wavelength coincides with the absorption band of Ag nanotriangles. This suggests that the enhancement of the incident field by surface plasmon polariton ͑SPP͒ excitation is responsible for the PL enhancement. On the other hand, for the sample having Au nanovoids, the PL enhancement is mainly made by the enhancement of effective radiative decay rate of Si-ncs by efficient excitation and scattering of SPPs.

Plasmonic engineering of spontaneous emission from silicon nanocrystals

“…Pioneering work has been performed by Biteen et al with nanoporous gold15, evidencing a four-fold enhancement of SiNCs' photoluminescence. Further studies have dealt with the coupling between SiNCs and plasmonics nanostructures such as Ag nanodisks16, metallic gratings171819, and Ag nanotriangles20. However, in most of these works, information obtained on coupling was limited by the contribution of uncoupled SiNCs, which were not located at a controllable distance of the metallic particles.…”

Surface plasmon enhanced LEDs

“…) enhanced light emission is achieved. Nanosphere lithography has been utilized to fabricate metallic NPs to increase the photoluminescence from silicon nanocrystals and GaN light emitters (Mochizuki et al , 2009;Mak et al , 2009). It can produce size-tunable periodic silver NP arrays that are plasmonically active nanostructures by selecting the appropriate nanosphere diameter and/or thickness (Hulteen et al , 1999;Jensen et al , 2000;Haynes and Van Duyne, 2001).…”

Enhanced luminescence from Si quantum dots/SiO2 multilayers by hydrogen annealing

“…It has been proposed that the Si QDs can be fabricated by annealing Si QDs-based multilayered structures, such as Si/SiN and Si/SiO 2 multilayers, and their size distribution can be well controlled in multilayered structures [1][2][3][4][5]. Both the photoluminescence and electro-luminescence have been reported at room temperature [4][5][6][7][8][9]. However, the emission efficiency from Si-based materials is still low and to find an appreciated way to improve the luminescence intensity is currently an interesting topic.…”

“…In order to further improve the luminescence efficiency, many approaches have been proposed to increase the internal quantum efficiency and the light extraction ratio [9][10][11][12]. One effective approach is to suppress the non-radiative recombination probability by passivation of the non-luminescent defect states.…”