Optimized Growth and Manipulation of Light–Matter Interaction in Stabilized Halide Perovskite Nanowire Array

Halide perovskite nanowires (HP-NWs) exhibit fascinating optical properties, making them attractive for advanced technologies. However, instability and lack of an effective synthetic protocol limit their commercialization. To address this, nanoporous anodized aluminum oxide (AAO) metamaterial is used as templates for the growth of CsPbBr₃ NW arrays. AAO functions as a growth template and a stabilizing medium. The NW array exhibits strong light-trapping ability, and the pore geometric features (pore radius-R and distance between pores-d) can potentially enhance the light-matter interactions (LMI). The impact of R and d on LMI within the AAO/CsPbBr₃ system using theoretical finite difference time domain (FDTD) simulations is demonstrated for the first time. Optimal LMI is observed with _R = d = 25 nm and 50 nm. Ligand-free synthesis of CsPbBr₃ NW arrays via spin-coating, drop-casting, and inverse temperature crystallization (ITC) is reported. While spin-coating and drop-casting results in poor pore filling, the modified ITC method achieves >90% pore filling with significant NW lengths. These findings highlight the potential of AAO templates for protecting CsPbBr3 and addressing synthetic challenges in HPs and other semiconductor NW arrays. This study provides key insights for LMI in HPs and advances NW array-based optical devices and renewable energy applications.