Kesterite tech news
On October 15, 2026, researchers published a study in Carbon Energy detailing a multiple synergistic optimization strategy for kesterite (CZTSSe) thin--film solar cells using a copper oxide–bismuth oxide (Cu₂O–Bi₂O₃) sacrificial interlayer. High--temperature processing of kesterite absorbers typically induces severe decomposition and copper loss at the back interface adjacent to the molybdenum contact. The introduction of the sacrificial Cu₂O–Bi₂O₃ interlayer successfully suppresses back--interface decomposition while releasing Cu⁺ ions to compensate for localized copper deficiencies and promote uniform elemental distribution. Simultaneously, Bi³⁺ ions diffuse bidirectionally into both the Cu₂ZnSn(S,Se)₄ absorber bulk and the MoSe₂ contact layer, reducing recombination losses and improving charge carrier transport across the heterojunction. This chemical interface engineering approach provides a scalable pathway to mitigate long--standing open--circuit voltage deficits in earth--abundant thin--film photovoltaics.