Lotus leaf structure improves perovskite efficiency by order of magnitude

Wearable and flexible electronic devices require photodetectors with high detection capabilities, but typical photodetectors are fragile, require high-temperature preparation processes, and have low photodetection efficiencies due to their low thickness. To address these issues, Hu et al. developed a method to incorporate a biomimetic nanostructure into a promising photodetector material, significantly enhancing its photoelectric conversion efficiency.

The photodetector is based on perovskite, which has the potential to serve as a high-performance, low-cost alternative to traditional materials. The authors incorporated a lotus-leaf nanostructure into the perovskite, allowing it to simultaneously optimize its crystallization structure while still retaining its optical nanostructure pattering. The lotus leaf’s nanostructure has a random distribution of differently sized humps, allowing incident light to be enhanced across a wide range of frequencies.

The resulting device demonstrated an enhancement of 1,100% in photogenerated current and an almost 40% increase in response speed.

“Our technique improved photoelectric conversion efficiency via two phenomena — resonance enhancement and local surface plasmon resonance — with one biomimetic nanostructure,” author Chi Ma said.

To fabricate the device, the team spin-coated and pre-annealed a precursor perovskite solution onto a substrate to reduce fluidity and enhance uniformity. A nanostructured PDMS template, replicated from a lotus leaf, was pressed onto the film in a vacuum-sealed bag at room temperature. Soft pressure ensured intimate contact between the PDMS and perovskite, aiding nanostructure formation. Finally, to measure the optical efficiency, the authors used time-resolved photoluminescence spectroscopy, comparing the intensity absorbed by patterned and unpatterned devices.

Further work will entail optimizing the perovskite optical structure to an even smaller scale, which enables the device to absorb a wider range of wavelengths.

Source: “Optimized perovskite photodetector achieved through optical manipulation via biomimetic nanostructure,” by Qirun Hu, Chi Ma, Jiarui Zhang, and Jun Dai1, Applied Physics Letters (2025). The article can be accessed at https://doi.org/10.1063/5.0249435 .