Electric control of single CsPbBr₃ nanorod emission

Highly anisotropic single perovskite nanorods (NRs) offer polarized emission and high photoluminescence (PL) quantum yields, making them promising candidates for quantum light sources. Here, we make use of the quantum-confined Stark effect (QCSE) to tune the optical response of individual CsPbBr₃ NRs with well-defined orientation relative to an external electric field. PL spectroscopy reveals a reversible QCSE, allowing to extract the polarizability and to prove the existence of a permanent dipole moment. A clear relation between field-induced emission energy shift, spectral line broadening, and PL intensity quenching is found. Interestingly, our study reveals a correlation between polarizability and zero-field PL intensity, hinting towards a screening effect of the passivating ligands. These findings offer a strategy for tuning perovskite NC emission, e.g., with respect to a cavity mode, in a well-defined way.