biostudies-literatureSui FScience and Technology Commission of Shanghai MunicipalityNational Natural Science Foundation of ChinaScience and Technology Commission of Shanghai Municipality (Shanghai Municipal Science and Technology Commission)National Natural Science Foundation of China (National Science Foundation of China)36https://www.ebi.ac.uk/biostudies/studies/S-EPMC9810696biostudies-literatureUnknown14(1)Two-dimensional (2D) van-der-Waals (vdW) layered ferroelectric semiconductors are highly desired for in-memory computing and ferroelectric photovoltaics or detectors. Beneficial from the weak interlayer vdW-force, controlling the structure by interlayer twist/translation or doping is an effective strategy to manipulate the fundamental properties of 2D-vdW semiconductors, which has contributed to the newly-emerging sliding ferroelectricity. Here, we report unconventional room-temperature ferroelectricity, both out-of-plane and in-plane, in vdW-layered γ-InSe semiconductor triggered by yttrium-doping (InSe:Y). We determine an effective piezoelectric constant of ∼7.5 pm/V for InSe:Y flakes with thickness of ∼50 nm, about one order of magnitude larger than earlier reports. We directly visualizNature communicationsSliding ferroelectricity in van der Waals layered γ-InSe semiconductor.PMC9810696622740611220417061790583TP201901961874043Yue FSui FZhang YJin MWu YNChu JQi RHuang RfalseSliding ferroelectricity in van der Waals layered γ-InSe semiconductor.Two-dimensional (2D) van-der-Waals (vdW) layered ferroelectric semiconductors are highly desired for in-memory computing and ferroelectric photovoltaics or detectors. Beneficial from the weak interlayer vdW-force, controlling the structure by interlayer twist/translation or doping is an effective strategy to manipulate the fundamental properties of 2D-vdW semiconductors, which has contributed to the newly-emerging sliding ferroelectricity. Here, we report unconventional room-temperature ferroelectricity, both out-of-plane and in-plane, in vdW-layered γ-InSe semiconductor triggered by yttrium-doping (InSe:Y). We determine an effective piezoelectric constant of ∼7.5 pm/V for InSe:Y flakes with thickness of ∼50 nm, about one order of magnitude larger than earlier reports. We directly visualiz2023-01-01T00:00:00Z2023 Jan2025-04-04T10:59:10.515Z2025-04-04T10:59:10.515ZS-EPMC98106963659678910.1038/s41467-022-35490-0