Transparent radiative cooler with high near-infrared interception for photothermal management

Abstract

Common glass lacking spectral adjustment capabilities fails to deliver energy-saving benefits, while radiative cooling technology without visible transparency compromises lighting and aesthetic requirements. In response, we introduce a novel solution termed as radiative cooler. (GIRC). GIRC efficiently reduces temperature increases caused by sunlight by specifically blocking near-infrared (NIR) rays, allowing visible light to pass through, and dispersing heat via the atmospheric window. Amazingly, GIRC manages multi-band spectral control with a simplified three-layer design, avoiding complex manufacturing steps and offering potential for large-scale production. Spectral analysis underscores GIRC's efficacy, demonstrating a maximum transmittance of 92.3 %, an impressive visible transmittance of 89.61 %, an average near-infrared transmittance of 51.89 %, and an emissivity of 94.70 % within the atmospheric window. The effectiveness of GIRC in cooling multi-crystalline silicon solar cells is demonstrated by a peak temperature drop of 9.1 °C, an average reduction of 5.12 °C, and a 3 % boost in solar cell efficiency over traditional glass alternatives. Indoor resistance assessments further attest to GIRC's cooling prowess, exhibiting a consistent temperature reduction of ∼7 °C relative to common glass, thus rendering it suitable for internal circuitry cooling applications. Energy consumption analysis underscores GIRC's significant efficiency gains, estimating a potential 17 % reduction in annual cooling energy consumption, compared to common glass configurations. The proposed GIRC glass not only moderates daytime temperatures but also preserves transparency and aesthetic appeal, thus holding immense promise for enhancing the thermal management of optoelectronic equipment in building structures.