Thermal Hysteresis in the Resistance of In2Se3 Film on Si(111) Surface

Properties of layered In2Se3 films grown on the Si(111) surface have been studied by in situ reflection electron microscopy. After the growth of 3-5 nm, the growth switches from layer-by-layer mode to the nucleation of 3D islands. Lateral dimensions of the islands increased from 310 to 410 nm when growth rate reduces from 0.02 nm/s to 0.007 nm/s. The electrical resistance of the In2Se3 films rises with 0.26 eV activation energy during cooling which corresponds to intrinsic β-In2Se3 phase having bandgap around 0.53 eVe At about 140 K, film's resistance decreases sharply by ~10⁴ times. The reverse transition occurs during heating to temperatures above 180 K. This hysteresis corresponds to a reversible structural transition β-In2Se3 ⇔ β'-In2Se3 observed previously in the 140-180 K range by scanning tunneling microscopy [ACS Nano 2 (2019) 10 6774-6782].