Rose Petal‐Inspired Random Lasers on Flexible PET Substrates for Achieving Wavelength Tunability and Speckle‐Free Imaging

Abstract Nanostructures inherent to biological tissues exhibit a range of functional properties, and soft lithography can be utilized to replicate these architectures for incorporation into diverse optoelectronic applications. In this study, a bio‐inspired random laser (RL) is presented by depositing inorganic CsPbBr 3 quantum dots (QDs) onto the surface of a silk fibroin replica film (SFRF), fabricated via nanocasting from a rose petal template. Compared to a pristine SF film, the all‐inorganic perovskite QDs deposited on the replica film exhibited multiple emission spikes, attributed to enhanced light scattering that facilitated coherent feedback. Additionally, the rose petal‐inspired perovskite QD RL exhibited a broader emission angle and lower spatial coherence, resulting in a low‐contrast granular pattern image with a contrast of approximately 0.053. By employing flexible PET as a substrate, the fabricated bio‐inspired all‐perovskite RL exhibits the ability to bend under mechanical stress. As curvature increases, the RL using SFRF exhibited a 2.4‐fold increase in intensity along with a 7.7 nm blue shift in the emission spectrum.