Self-assembled 3D biomimetic flower-like Bi2WO6 for significantly enhanced photodetection performance

Bismuth tungstate (Bi 2 WO 6 ), a typical Aurivillius-phase layered oxide, possesses considerable application potential in optoelectronic devices owing to its suitable bandgap structure and favorable chemical stability. However, conventional two-dimensional (2D) materials often suffer from limited light-harvesting efficiency due to their restricted thickness and short optical path length, which hampers their photoelectric conversion performance to a certain extent. To improve this drawback, inspired by the hierarchical structure of natural petals, we constructed a novel three-dimensional (3D) flower-like Bi 2 WO 6 micro-nanostructure assembled from ultrathin nanosheets via a controllable hydrothermal strategy. This special morphology can effectively enlarge the specific surface area and induces multiple light scattering, significantly boosting photo-electric conversion. Consequently, the photodetector based on nanoflower structures exhibits obviously optimized photoresponse performance. Its response time is greatly shorten to 40/285 ms (rise and fall processes respectively). The photocurrent density reaches over 2.34 μA per square centimeter, which is more than doubled that of unoptimized samples, while the responsivity attains 48.7 μA W −1  cm −1 with an increase of approximately sixfold. Furthermore, the fabricated flexible devices can maintain favorable photoresponse capabilities under various bending angles, demonstrating satisfactory mechanical flexibility and stability. This study not only elucidates the underlying mechanism by which the three-dimensional biomimetic flower-like architecture enhances optoelectronic performance, but also provides new insights for the design of high-performance flexible biomimetic photodetectors.