# Tri-Band Regulation and Split-Type Smart Photovoltaic Windows for Thermal Modulation of Energy-Saving Buildings in All-Season

## TL;DR

This paper introduces smart windows that can save energy year-round by regulating solar and thermal energy using advanced materials and scalable manufacturing.

## Contribution

A tri-band regulation smart photovoltaic window with reduced driving voltage and high solar transmittance is developed for all-season energy savings.

## Key findings

- Driving voltage of PDLCs is reduced by 28.1% without compromising solar transmittance or modulating ability.
- The SPW combines perovskite solar cells and thermal management units for zero-energy solar regulation and energy compensation.
- The design enables exceptional energy-saving performance in all seasons with scalable manufacturing potential.

## Abstract

Broadening the modulation range and decreasing the driving voltage of polymer dispersed liquid crystals via molecular engineering without sacrificing high solar transmittance (transparent state) and solar modulating ability.Modulating capability of the smart photovoltaic windows across visible, near-infrared and mid-infrared bands enabling superb energy-saving performance in all season.Holding a great potential for real-world application due to their scalable manufacturing technology.

Broadening the modulation range and decreasing the driving voltage of polymer dispersed liquid crystals via molecular engineering without sacrificing high solar transmittance (transparent state) and solar modulating ability.

Modulating capability of the smart photovoltaic windows across visible, near-infrared and mid-infrared bands enabling superb energy-saving performance in all season.

Holding a great potential for real-world application due to their scalable manufacturing technology.

The online version contains supplementary material available at 10.1007/s40820-025-01985-w.

Energy-saving buildings (ESBs) are an emerging green technology that can significantly reduce building-associated cooling and heating energy consumption, catering to the desire for carbon neutrality and sustainable development of society. Smart photovoltaic windows (SPWs) offer a promising platform for designing ESBs because they present the capability to regulate and harness solar energy. With frequent outbreaks of extreme weather all over the world, the achievement of exceptional energy-saving effect under different weather conditions is an inevitable trend for the development of ESBs but is hardly achieved via existing SPWs. Here, we substantially reduce the driving voltage of polymer-dispersed liquid crystals (PDLCs) by 28.1 % via molecular engineering while maintaining their high solar transmittance (Tsol = 83.8 %, transparent state) and solar modulating ability (ΔTsol = 80.5 %). By the assembly of perovskite solar cell and a broadband thermal-managing unit encompassing the electrical-responsive PDLCs, transparent high-emissivity SiO2 passive radiation-cooling, and Ag low-emissivity layers possesses, we present a tri-band regulation and split-type SPW possessing superb energy-saving effect in all-season. The perovskite solar cell can produce the electric power to stimulate the electrical-responsive behavior of the PDLCs, endowing the SPWs zero-energy input solar energy regulating characteristic, and compensate the daily energy consumption needed for ESBs. Moreover, the scalable manufacturing technology holds a great potential for the real-world applications.

The online version contains supplementary material available at 10.1007/s40820-025-01985-w.