Customized Plasmon Materials for Applications in Thermophotonics

Local optical heating and the control of heat fluxes using light at the nanoscale are integral to many applications, such as photothermal therapy, photocatalysis, thermophotovoltaics, and so on. Photoheating temperature can be controlled quite simply by changing the intensity of the incident light. However, the problem of fine tuning the temperature of nanostructures at a constant pumping intensity still remains unsolved. A tunable nanoscale heat source has been developed, consisting of a titanium oxynitride (TiON) plasmonic antenna placed on top of a silicon cylinder. It has been experimentally shown that the change in the heating temperature can reach C at a fixed intensity of the incident radiation 5 Mw/cm . The proposed approach is based on the controlled oxidation of TiON. This effect made it possible to flexibly adjust the permittivity of the material of the plasmonic nanostructure. In this way, it is possible to control the absorption section and, therefore, the photoheating temperature.