Strong Linear Photoluminescence Modulation by an External Electric Field in Epitaxial Halide Perovskite Nanowires

Metal-halide perovskites (MHPs) hold great potential for next-generation optoelectronic technologies due to their remarkable characteristics. While the influence of strain on the intrinsic properties of MHPs is gaining interest, its combined effect with an external electric field (E-field) has been largely overlooked. Using an electric-field-dependent Photoluminescence (PL) intensity study on heteroepitaxially strained surface guided CsPbBr₃ nanowires, we reveal an unexpected linear coupling between the alternating field and the PL intensity with a significant modulation depth (up to 40%), stemming from an induced internal dipole. Low-frequency polarized-Raman spectroscopy shows structural modifications in the nanowires under an external electric field, associated with the observed polarity. These results reflect the important interplay between an external E-field and strain in MHPs and offer new insight into the design of novel MHP-based nano-optoelectronics.