We propose to study the defect behaviour of ZnGeN2 as a representative material for the emerging class of Zn-IV-N2 solar absorber materials. As earth-abundant alternatives to III-V materials, Zn-IV-N2 materials are greatly interesting, but as ternary materials, their defect behaviour needs to be understood in order to rationalise the synthesis process for applicable solar devices. Most prominently cation anti-site defects shall be characterised in this beamtime, since they are virtually indistinguishable from X-ray diffraction.