Multifunctional Plasmonic WO_3-X@CdS Heterojunction Engineering to Achieve Efficient Perovskite Solar Cells

To broaden the light-harvesting spectrum of perovskite solar cells (PSCs), WO 3-X @CdS heterojunctions have been synthesized by in situ growing CdS nanoparticles on WO 3-X nanorods rich in oxygen vacancies. After introducing them into perovskite layers by the antisolvent method, the localized surface plasmon resonance (LSPR) effect of WO 3-X @CdS extends photon absorption into the near-infrared region, while both lattice match and its coordination with iodide ions facilitate uniform nucleation and crystallization process to obtain high-quality perovskite films. Moreover, this dual-functional material simultaneously optimizes the hole transport layer/perovskite energy alignment and accelerates the interfacial charge transfer via LSPR-induced near-field enhancement effects. The spectral expansion and improved carrier dynamics synergistically boost the power conversion efficiency to 25.08%, demonstrating heterojunction engineering as a viable strategy for advancing broadband PSCs and other optoelectronic devices.