Photoluminescence plasmonic enhancement in InAs quantum dots coupled to gold nanoparticles

Photoluminescence enhancement due to dipole field from gold nanoparticles was observed at 77 K for GaAs capped InAs quantum dots. The gold nanoparticles were coupled to the surface of the cap layer by using dithiol ligands. The enhancement was investigated as a function of the GaAs capped layer thickness. An order of magnitude enhancement in the emission was observed in samples with a cap thickness of 12 nm. This enhancement however is drastically decreased in samples with a cap thickness of 200 nm. The observed enhancement is interpreted in terms of photon scattering from the large dipole scattering cross section.

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► We synthesize gold nanoparticles and deposit them on InAs quantum dot samples.
► We examine the surface plasmon effects on the photoluminescence as a function of cap layer thickness and excitation power.
► Decreasing the cap layer thickness will increase the photoluminescence intensity.
► Increasing the laser power will decrease the photoluminescence enhancement.