Ultralarge Pixel Array Photothermal Film based on 3D Self-Suspended Microbridge Structure for Infrared Scene Projection

Infrared emitter is highly desirable for applications in infrared imaging and infrared stealth technology. It is also a core device in infrared scene generation. Light-driven photothermal film has attracted considerable interest due to its outstanding photothermal properties and easy fabrication. However, the existing photothermal films suffer from low photothermal conversion efficiency (PCE) as well as small sizes. The improvement of the PCE is usually achieved at the expense of dynamic frame rate. Here, this work designs and fabricates a photothermal film based on 3D self-suspended microbridge structure. Silicon (Si) microbridges are introduced into each microstructure to manipulate the thermal conductivity of the films. By optimizing the parameters of the Si microbridges, the high PCE and fast frame rate are both achieved. Moreover, the 3D structure microbridge film is 4-inch in diameter, forming an ultralarge array with over 2200 × 2200 pixels. Finally, a high PCE infrared scene projector is realized based on this photothermal film. A visible image is projected on the film, the 3D-microstructured photothermal film absorbs the visible light and emits an infrared image same as the visible one with high resolution and fast frame rate due to the excellent photothermal properties.