Similar calculations on p-type SnS and SnSe predicted averaged ZT max = 1.75 and 2.81 respectively. Compared to n-type Bi 2 SO 2 and Bi 2 SeO 2 , the Sn chalcogenides show larger σ and |S|, resulting in ∼ 4× larger PFs, and comparable or lower κ. With large n, however, p-doped Bi 2 SO 2 is predicted to have a ∼ 2× larger σ and comparable S to SnS, although the resulting 2× larger PF is partially mitigated by the higher κ. The conductivity of p-doped Bi 2 SeO 2 is again 1.6× larger than predicted for SnSe, with a comparable S, but the 50% larger κ results in a similar predicted ZT max . Compared to Sn chalcogenides, the p-doped Bi 2 ChO 2 can therefore sustain a large S at doping levels that lead to a considerably larger σ and PF, but the ZT max are limited by the proportionally larger κ el (c.f. Eq. 3) and larger intrinsic κ latt .