Electric-Field-Induced Giant Resonant Enhancement of Second Harmonic Generation in Two-Dimensional Hybrid Perovskite

For the advancement of optical information technology, nonlinear optical systems with tunable and reconfigurable functionality are essential. Electric-field-induced second harmonic generation (EFISH) is a promising approach, enabling electrical control over nonlinear light-matter interactions. However, efficient, simple, and highly adaptable EFISH materials or systems have yet to be reported. In this study, we demonstrate that two-dimensional (2D) organic–inorganic hybrid perovskites (OIHPs) exhibit a remarkable EFISH performance with significant tunability. The second harmonic generation is dramatically enhanced at excitonic resonance, increasing by more than 2 orders of magnitude when a 70 kV/cm electric field is applied. In addition, this efficient EFISH is observed even in nonpolar and nonchiral 2D-OIHPs. This study opens up the broader potential of low-dimensional OIHPs as nonlinear optical materials, leading to the development of tunable and dynamic nonlinear optical systems with simple and versatile material designs.