“…However, owing to the challenge of synthesis and complex intrinsic defects, Re-based HH compounds have been rarely studied experimentally. 21 In 2020, DyNiSb, ErNiSb, TmNiSb, and LuNiSb were successfully prepared by Ciesielski et al ., 22 of which the κ L were reported to be about 2.0–5.0 W m −1 K −1 at 300 K. The κ L of YbNiSb, prepared by Huang et al ., 21 was reported to be about 2.2 W m −1 K −1 at 300 K. Compared to other typical HH compounds ( κ L : 12 W m −1 K −1 for VFeSb, 23 6 W m −1 K −1 for ZrNiSn, 11 18 W m −1 K −1 for ZrCoSb 24 ), the experimentally reported low κ L s in ReNiSb-based HH compounds might be favorable for good TE performance. To verify this, more systematic studies on the optimization of TE performance should be carried out.…”