Ideal Photothermal Materials Based on Ge Subwavelength Structure
Jingjun Wu,
Kaixuan Wang,
Cong Wei,
Jun Ma,
Hongbo Xu,
Wanguo Zheng,
Rihong Zhu
Affiliations
Jingjun Wu
School of Electronic and Optical Engineering, Nanjing University of Science and Technology, Nanjing 210094, China
Kaixuan Wang
School of Electronic and Optical Engineering, Nanjing University of Science and Technology, Nanjing 210094, China
Cong Wei
School of Electronic and Optical Engineering, Nanjing University of Science and Technology, Nanjing 210094, China
Jun Ma
School of Electronic and Optical Engineering, Nanjing University of Science and Technology, Nanjing 210094, China
Hongbo Xu
MIIT Key Laboratory of Critical Materials Technology for New Energy Conversion and Storage, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin 150001, China
Wanguo Zheng
School of Electronic and Optical Engineering, Nanjing University of Science and Technology, Nanjing 210094, China
Rihong Zhu
School of Electronic and Optical Engineering, Nanjing University of Science and Technology, Nanjing 210094, China
Photothermal materials often prioritize solar absorption while neglecting thermal radiation losses, which diminishes thermal radiation conversion efficiency. This study addresses this gap by introducing a germanium (Ge) subwavelength structure (SWS) designed to optimize both solar absorption and infrared emissivity. Using a self-masked reactive ion etching (RIE) technique, we achieved a peak absorption of 98.8% within the 300 nm to 1800 nm range, with an infrared emissivity as low as 0.32. Under solar illumination of 1000 W/m2, the structure’s temperature increased by 50 °C, generating a heating power of 800 W/m2. Additionally, it demonstrated good mechanical and thermal stability at high temperatures and possessed a hydrophobic angle of 132°, ensuring effective self-cleaning. These characteristics make the Ge SWS suitable for application in solar panels, displays, sensors, and other optoelectronic devices.
