“…For instance, 2D ferroelectricity has been demonstrated in CIPS, WTe 2 , In 2 Se 3 , SnS, SnTe, Bi 2 O 2 Se, and 1T‐MoTe 2 . [ 14,54,74,78,82,83,100,162–165 ] Notably, traditional ferroelectric materials are insulator, but researchers proved that 2D ferroelectric materials could be insulators, semiconductors, and metals, which endows them with wider applications in electronic and optoelectronic devices. In this section, the intrinsic ferroelectricity in 2D layered materials is summarized.…”