Surface plasmon enhanced light emission from semiconductor materials

physica status solidi (c) 07/2008; 5:2822--2824. DOI: 10.1002/pssc.200779287

ABSTRACT Surface plasmon (SP) coupling technique was used to enhance light emissions from semiconductor nanocrystals with evaporated metal layers. We found that the SP coupling can increase the internal quantum efficiencies (IQE) of emission from CdSe-based nanocrystals regardless of the initial efficiencies. This suggests that this technique should be much effective for various materials that suffer from low quantum efficiencies. We also obtained 70-fold enhancement of emission from silicon nanocrystals in silicon dioxide. Obtained IQE value is 38

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    ABSTRACT: In this paper we demonstrate how an elliptically shaped semiconductor microcavity can be used to generate surface plasmons (SP) mode by pumping current and injecting optical pulse. After achieving stable lasing mode, external magnetic field is applied to a small elliptical confined area on the elliptical microcavity. The applied magnetic field produces Lorentz torque and "pushes" the electrons to the edge of the microcavity. Strong electron plasma is built up on the boundary of the microcavity and air interface as more electrons accumulate. The laser light source interacts with the electron plasma at the boundary of microcavity and excites surface plasmon mode. The direct excitation of SPP modes could be used to extract the laser light from elliptical microcavity source and results in a lower coupling loss and higher efficient small coupling system.
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    ABSTRACT: We report an enhancement in light emission efficiency form Si nanocrystal (NC) light-emitting diodes (LEDs) via surface plasmons (SPs) by employing Au nanoparticles (NPs). Photoluminescence intensity of Si NCs with Au NPs was enhanced by 2 factors of magnitude due to the strong coupling of Si NCs and SP resonance modes of Au NPs. The electrical characteristics of Si NC LED were significantly improved, which was attributed to an increase in an electron injection into the Si NCs due to the formation of inhomogeneous Schottky barrier at the SiC-indium tin oxide interface. Moreover, light output power from the Si NC LED was enhanced by 50% due to both SP coupling and improved electrical properties. The results presented here can provide a very promising way to significantly enhance the performance of Si NC LED.
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