Nature CommunicationsHalogen substitution strategy of spacer cations in two-dimensional perovskite ferroelectrics gives giant anomalous photovoltaic effectWenjing LiYu MaYi LiuHaojie XuWuqian GuoQingshun FanLiwei TangHao RongJunhua LuoZhihua Sun2025-08-14Full textDOI https://doi.org/10.1038/s41467-025-62903-7