Bistable photonic nanostructures based on molecular spin crossover complexes

International audience; In this paper we discuss the elaboration, optical properties and possible applications of thin films and nano-patterns of molecular spin crossover complexes. These bistable nanostructures can respond reversibly with fast response times to various external stimuli, such as temperature changes, application of an external pressure, light irradiation or exposure to gas/vapor molecules. The response can be either transient (gating) or non-volatile (switching) depending on the experimental conditions. We show that these assets provide a very appealing scope for a variety of applications including tunable photonic devices, thermal imaging and chemical sensors. In particular, we discuss three photonic application principles based on fluorescence energy transfer, grating diffraction and guided plasmon-polariton waves.