The Skeptics Guide to the Universe

Control of the phase evolution of kesterite by tuning of the selenium partial pressure for solar cells with 13.8% certified efficiency - Nature Energy

Secondary phases or multi-step phase formation lead to poorly crystallized and defective kesterite films. Now Zhou et al. convert precursors into kesterite in a single step, using low partial pressure of selenium, and achieve solar cells with 13.8% certified efficiency.

A strategy to fabricate kesterite solar cells with a 13% efficiency

Kesterite (Cu2ZnSnS4, CZTS) is a sulfide mineral with a unique lattice structure that can be considered as derived from chalcopyrite CuInSe2 (CIS) by substituting two atoms of In3+ in the chalcopyrite by one atom of Zn2+ and one atom of Sn4+. The elements included in this mineral and its derivatives Cu2ZnSn(S,Se)4 (CZTSSe) are less-toxic and abundant on Earth, which could be very advantageous for the development of more sustainable and low-cost technologies.