(color online) (a) Room temperature cation defect concentration (n_CD)-dependent normalized lattice thermal conductivity (κ_L) for CuGaTe₂ solid solutions with (red) and without (black) vacancies.^[95] Reproduced from Ref. [95] with permission from the Royal Society of Chemistry. (b) Plots of room-temperature κ_L and modeled κ_L against the molar fraction of selenium of the complete solid solution series Cu₂ZnGeSe_4−xS_x with x = 0–4.^[96] Reproduced from Ref. [96] with permission from the American Chemical Society.