A Low‐Voltage Multi‐Band Tunable Smart Window for Self‐Adaptive Thermoregulation

Abstract

ABSTRACT As a crucial smart window technology, polymer‐dispersed liquid crystal (PDLC) faces two major performance limitations in applications: high driving voltage and limited spectral regulation. Herein, we develop a PDLC‐based smart window that operates at low voltage and enables multi‐band modulation. By incorporating p–n heterojunction nanoparticles, the electro‐optical performance of the PDLC film is significantly enhanced. Specifically, a 35.1% reduction in saturation voltage (to 16.3 V) and an increased contrast ratio of 130 were achieved at a film thickness of 20 µm. Subsequent integration of W‐VO 2 /PMMA resulted in a V‐PDLC smart window. The resulting device demonstrates switchable long‐wave infrared emissivity (ε LWIR = 0.75 at high temperature; ε LWIR = 0.41 at low temperature), enabling passive radiative cooling while maintaining high visible light transmittance and efficient near‐infrared modulation. Field test and energy simulations confirmed that the system not only provides effective temperature regulation (approximately 8°C cooling during the day and 2°C insulation at night) but also demonstrates significant energy‐saving potential across various climatic zones. This research offers valuable insights for developing smart windows with adaptive and on‐demand adjustment capabilities.