“…Large-size diamines, which can form 2D perovskites with a formula of L(SMX 3 ) n −1 MX 4 , may drive quasi-2D perovskite with different structures. , In diamine-based quasi-2D perovskite there is no van der Waal gap between the organic cations, which sets up better defensive wall to prevent the invasion of moisture or heat, thus increasing the rigidity and stability of perovskite . Similarly, EDBE 2+ -based ( EDBE 2+ = 2,2-(ethylenedioxy)bis(ethylammonium)) quasi-2D perovskite showed decreased grain size and enhanced morphology . Recently, Yuan et al introduced 1,4-Bis(ammoniummethyl)benzene ( P-PDA 2+ ) into quasi-2D perovskite, which exhibits stronger interaction with inorganic octahedron compared with traditional large cation monoamine (such as PEA + ).…”