A research team led by Prof. Zhang Jian at the Institute of Solid State Physics, Hefei Institutes of Physical Science, Chinese Academy of Sciences, in collaboration with Prof. Xiao Chong from the University of Science and Technology of China and Prof. Zhang Yongsheng from Qufu Normal University, achieved a peak ZT value of 2.03 at 873 K in chalcopyrite-based thermoelectric materials using a novel dual antisite defect strategy.