Fig. 1: Indium selenide structural phases and electronic properties.
From: Indium selenides for next-generation low-power computing devices
a, Structures of InSe (left) and In2Se3 (right) showing their phase variants and stacking orders, with the binary In–Se phase diagram (centre). b, Thermal velocity as a function of thickness for InSe compared with other semiconducting materials such as 2D transition metal dichalcogenides (TMDs), 3D compound semiconductors and 3D silicon9. c, Thickness-dependent bandgaps of the indium selenides compared with the semiconducting 2D TMDs and bulk silicon6,25,28,41,44. d, Coercive field and remnant polarization of α-In2Se3 compared with other 2D van der Waals ferroelectrics130,141,142,143,144,145,146, such as bilayer graphene (BLG), α-phase SnS (αSnS), CuInP2S6 (CIPS) and rhombohedral-stacked MoS2 (3R-MoS2) (filled symbols) as well as conventional 3D ferroelectrics147,148,149,150 such as scandium-doped AlN (AlScN), poly(vinylidene fluoride) (PVDF), HfxZr1–xO2 (HZO), SrBi2Ta2O9 (SBT), BaTiO3 (BTO) and Pb(Zr,Ti)O3 (PZT) (open symbols). Here, all materials exhibit out-of-plane ferroelectricity, except for α-phase SnS which has in-plane (αSnS (IP)) ferroelectricity.
