Programmable Micelle Templated Electrochemical Deposition Synthesis of Mesoporous Chalcogenide Semiconductors Thin Film for High-Performance Photodetector

Surface topography serves as powerful tuning knobs for enhancing the performance of compound semiconductor-based photodetectors. However, existing studies have been confined to microscale or submicron structures (e.g., photonic crystals) due to the challenges in fabricating well-defined sub-50 nm mesostructures in semiconductor thin films. Here, a programmable and scalable approach to synthesize mesoporous Bi 2 Se 3 (mBi 2 Se 3 ) films with precisely tunable pore size (13–30 nm), porosity, thickness, and crystallinity via amphiphilic block copolymer-templated electrochemical deposition is presented. The resulting nanoscale spherical interfaces enable multi-level light scattering, significantly boosting photodetector performance. The mBi 2 Se 3 /Au/Si based optimized devices exhibit a responsivity (R) of 6 mA W −1 , a detectivity (D*) of 10 13 Jones, and a sensitivity ( S ) of 10 6 cm 2 /W—orders of magnitude higher than their non-porous counterparts, and superior to other reported Bi 2 Se 3 based or mesostructured photodetectors. This work advances optical micro/nanostructure engineering down to the 10-nm scale, paving the way for next-generation photodetectors that simultaneously achieve high responsivity, detectivity, and speed. These findings hold great promise for applications in high-resolution infrared imaging and real-time image recognition.