Home – Home – Jornals – Avtometriya 2023 number 1

Optical heat generation and control at the nanoscale play a key role in many applications, such as photothermal therapy, photocatalysis, thermophotovoltaics, etc. Adjusting the photoheating temperature can be easily performed by tuning the intensity of the incident light. However, fine tuning of the temperature of nanostructures at a fixed light intensity still remains a challenging task. In this work, we propose a tunable optical nanoheater that consists of a titanium oxynitride (TiON) plasmonic antenna placed on top of a silicon cylinder. It has been experimentally shown that, at a fixed intensity of 5 MW/cm², a change in the photoheating temperature up to 100 ^◦C can be achieved. The underlying approach is based on the controlled oxidation of TiON. This allows for flexible tailoring the permittivity of TiON. As a result, the photoheating temperature can be tuned, which is associated with the modification of the absorption cross-section of plasmonic nanostructure.