An inconvenient truth of thermal nonreciprocity's impact on radiative cooling efficiency

Mengqi Liu received her bachelor's degree in energy and power engineering from Shandong University in 2016 and a joint PhD degree in engineering thermophysics from Shanghai Jiao Tong University (SJTU) and National University of Singapore (NUS) in 2022. Now, she is a postdoctoral researcher at SJTU and a visiting scholar at NUS. Her research interests include micro/nanoscale thermal radiation, nonreciprocal thermal photonics, topological properties in thermal photoncis, metamaterials energy devices, etc. Shenghao Jin obtained his bachelor's degree at the School of Energy and Power Engineering at Dalian University of Technology, China. He is currently a PhD student in the Institute of Engineering Thermophysics at SJTU, China. His research interests include the design of colorful radiative cooling devices, smart windows, electrochromic display, and efficient dynamic spectrum engineering. Chenglong Zhou obtained his bachelor's degree in energy and power engineering from Harbin Engineering University, a master's degree in engineering thermophysics from Harbin Institute of Technology, and a PhD from Harbin Institute of Technology. After that, he joined the Department of Energy Science and Engineering, Harbin Institute of Technology, in 2024, where he is currently working as an associate researcher. He works in the near-field radiative heat transfer, aiming to address the constraints imposed by the blackbody radiation limit and the challenges in precise regulation of radiative energy utilization within novel energy systems. Boxiang Wang received a BS degree from Huazhong University of Science and Technology in 2012 and then a PhD from SJTU in 2018. Then he worked successively as a postdoctoral researcher (2018–2021), an assistant professor (2021–2022), and then an associate professor (2022–2024) at the same university. After that, he joined Shanghai Institute of Microsystem and Information Technology (SIMIT), Chinese Academy of Sciences, as a young professor and the principal investigator of SIMIT Thermal Radiation Group. His research interests include nanoscale thermal radiation, nanophotonics, micro-electro-mechanical system (MEMS) sensors, smart windows and radiative cooling. Changying Zhao is the chair professor and the director of the Institute of Engineering Thermophysics of SJTU. His research covers micro/nanoscale thermal radiation and metamaterial energy devices, advanced thermal energy storage and hydrogen storage, and heat transfer in porous media. He has published over 300 papers in peer-reviewed high-quality journals with over 20,000 citations in total. His contributions have been recognized through prestigious awards, including a 2023 William Begell Medal and 2024 Prominent Research Award. He is the editor-in-chief of Carbon Neutrality, an associate editor of Thermal Science and Engineering Progress, and an editorial board member of several other international journals. Cheng-Wei Qiu is the provost's chair professor at the Department of Electrical and Computer Engineering of NUS. Prof. Qiu is a fellow of the Academy of Engineering, Singapore. He is also a fellow of APS, Optica, SPIE, and The Electromagnetics Academy, USA. He is foreign fellow of the Chinese Optical Society. He received his B.Eng. degree from University of Science and Technology of China in 2003 and PhD from NUS in 2007. He was a postdoctoral fellow at the Physics Department in MIT thereafter. His research is well known for the structured surface of multi-dimensional fusion, beam manipulation, and thermal metamaterials.