Defect formation energy (∆E D q ) varies with the thermodynamic growth conditions (Eq. 3) of a material, which are determined by the chemical potentials of the constituent elements. In the case of Y 2 Te 3 , ∆E D q will depend on the chemical potentials of Y (µ Y ) and Te (µ Te ). The elemental chemical potentials µ i are commonly expressed relative to their chemical potentials at standard conditions such that µ i = µ 0 i + ∆µ i , where ∆µ i quantifies the deviation from standard conditions. The allowable range of ∆µ i is dictated by the thermodynamic phase stability of the material in the grand potential phase diagram obtained through a convex hull analysis.