Refractory Plasmonics without Refractory Materials.

Refractory plasmonics deals with metallic nanostructures that can withstand high temperatures and intense laser pulses. The common belief was that refractory materials such as TiN are necessary for this purpose. Here we show that refractory plasmonics is possible without refractory materials. We demonstrate that gold nanostructures which are overcoated with 4 and 40 nm Al2O3 (alumina) by an atomic layer deposition process or by thick IC1-200 resist can withstand temperatures of over 800 °C at ambient atmospheric conditions. Furthermore, the alumina-coated structures can withstand intense laser radiation of over 10 GW/cm2 at ambient conditions without damage. Thus, it is possible to combine the excellent linear and nonlinear plasmonic properties of gold with material properties that were believed to be only possible with the lossier and less nonlinear refractory materials.