Lead halide perovskite for efficient optoacoustic conversion and application toward high-resolution ultrasound imaging

Lead halide perovskites possess high optical absorption, low specific heat capacity, and low thermal diffusion, yet their thermal properties and related devices have been underexplored. Here, leveraging these attributes, we demonstrate perovskite-based optoacoustic transducers. Density functional theory reveals overlap between optical and acoustic phonons in MAPbI3 that facilitates acoustic-to-optical phonon up-conversion, explaining the experimentally observed low thermal diffusion coefficient. A PDMS/MAPbI3/PDMS device achieves a −6 dB bandwidth of 40.8 MHz (center frequency 29.2 MHz) and a record optoacoustic conversion efficiency of 2.97 × 10−2, along with high acoustic pressure. Miniaturized fiber-integrated devices enable high-resolution ultrasound imaging, clearly resolving fine structures of fisheyes, highlighting the competitiveness of perovskite-based optoacoustic transducers.