Large-Δε relaxor-like liquid crystals enable submillisecond switching and millivolt driving

Abstract

Nematic liquid crystals (NLCs) are not only a key materials group in the display industry but also lay an essential foundation for many emerging technologies, such as adaptive optical elements and phase modulators. However, the electro-optical performance of conventional NLCs is not sufficient; it is primarily limited by their relatively high driving voltages and millisecond response times. Here, we demonstrated that an emerging type of liquid crystal, dubbed the nematic relaxor ferroelectric (nRFE), exhibits an ∼10× lower switching threshold (V_th < 0.5 V) and sub-millisecond rise time (τ_on < 300 µs). The performance surpasses the conventional NLCs. Rise time scales linearly with 1/E², indicating a dielectric reorientational pathway similar to that of conventional NLCs. The acceleration originates from strong polarization fluctuations, which cause a dielectric anisotropy (Δε) > 10× higher than in NLCs (Δε > 50). Our findings suggest that nRFE materials present optimal properties for addressing long-standing technological challenges, potentially paving the way for the development of LC-based modulators, such as silicon-based LC on silicon (LCoS) phase modulators.