Intrinsic point defects and complexes in the quaternary kesterite semiconductor Cu 2 ZnSnS 4

Current knowledge of the intrinsic defect properties of ${\text{Cu}}_{2}{\text{ZnSnS}}_{4}$ (CZTS) is limited, which is hindering further improvement of the performance of CZTS-based solar cells. Here, we have performed first-principles calculations for a series of intrinsic defects and defect complexes in CZTS, from which we have the following observations. (i) It is important to control the elemental chemical potentials during crystal growth to avoid the formation of secondary phases such as ZnS, CuS, and ${\text{Cu}}_{2}{\text{SnS}}_{3}$. (ii) The intrinsic $p$-type conductivity is attributed to the ${\text{Cu}}_{\text{Zn}}$ antisite which has a lower formation energy and relatively deeper acceptor level…