Work

Engineered periodic conical absorbers achieving near-unity solar absorption for energy harvesting

Year: 2025

Type: article

Abstract: • Design and fabrication of PCA using CNC-drilled template replication. • 99.51 % solar absorptance from visible to near-infrared by engineered PCA. • 71.39 % photothermal conversion efficiency under one-sun irradiation. • PCA-based STEG system delivers 405 μW cm −2 output power. • Demonstrated resistance to thermal shock, corrosion and mechanical deformation. Broadband high-absorption materials are essential for practical applications in solar energy harvesting. The fabrication of these materials typically relies on the construction of cavity structures to enhance light absorption. However, achieving near-unity broadband absorption while maintaining precise cavity control, enabling large-area fabrication, and ensuring process simplification remains a critical challenge. This study designs cavity-structured absorbers and utilizes ray-tracing simulations to investigate the effects of cavity shape and geometric parameters on the absorptance of absorbers. Computer numerical control (CNC) drilling was innovatively combined with template replication methods to fabricate a periodic conical absorber (PCA) featuring precisely controlled cavity structures that are scalable for large-area production. The engineered conical cavity structures of the PCA achieve an integral absorptance of 99.51 % across the visible to near-infrared spectrum. Under one-sun irradiation, the PCA exhibits highly efficient solar energy absorption, with the surface temperature rising to approximately 88 °C, corresponding to a photothermal conversion efficiency of 71.39 %. Furthermore, the PCA-based solar thermoelectric generator (STEG) system delivers an ultrahigh output power of 405 μW cm −2 . Additionally, the PCA demonstrates strong resistance to thermal shock, corrosion, and mechanical deformation, fulfilling the requirements for solar energy harvesting and utilization.

Source: Materials & Design

DOI: 10.1016/j.matdes.2025.114541

Authors: Yalan Wang, Youhua Xiao, Mingxing Piao, Chaolong Li, Haofei Shi, Xiao Wang

Institutions: Chinese Academy of Sciences, Chongqing Institute of Green and Intelligent Technology, University of Chinese Academy of Sciences

Language: English

Topic: Thermal Radiation and Cooling Technologies

Subfield: Civil and Structural Engineering

Field: Engineering

Domain: Physical Sciences

SDG: Affordable and clean energy

Open Access status: gold

Estimated APC paid: $3,650