Tunable surface plasmon mediated emission from semiconductors by using metal alloys

The authors have explored the possibility of using binary metal alloys on surface plasmon mediated emission from semiconductor. By adjusting the alloy composition, they have found that the surface plasmon resonance energy can be tuned to match with the emission energy of semiconductor so that the energy transfer process between the semiconductor and surface plasmons can be optimized. They have calculated the plasmonic density of states and Purcell factor for ZnO and ZnTe at different alloy compositions and the results support the argument. Experimentally, they have prepared Alx Ag1-x ZnO films at different compositions and have measured their photoluminescence. The band-edge emission from Al0.8 Ag0.2 ZnO is found to be ∼60 times stronger than that of bare ZnO, which is consistent with the theoretical prediction. As a result, metal alloys can be considered as a simple and effective means in optimizing the surface plasmon mediated emission.