Nature Energy, Published online: 13 July 2026; doi:10.1038/s41560-026-02111-9

Elemental diffusion in Cu2ZnSnS4 induces secondary phases and defects, limiting the open-circuit voltage in associated solar cells. Wang et al. introduce two-stage copper incorporation to suppress copper out-diffusion, enabling 12.4% efficiency and an 874-mV open-circuit voltage in solar cells.

Nature Energy, Published online: 12 June 2026; doi:10.1038/s41560-026-02073-y

Lyu et al. show that industrial overcapacity, long viewed as a burden, can be repurposed. Using China’s aluminium sector as an example, they demonstrate that excess capacity and material storage can provide seasonal flexibility to lower energy costs.