Electron Microscopy Study of Stacking Defects in β-In2Se3
In2Se3 has recently received much attention because of its excellent ferroelectric,thermo-electric,and photoelectric properties.However,the stacking defects,known as an important factor affect-ing the properties of van der Waals layered materials,have not yet been explored for In2Se3.Herein,the atomic configurations of stacking defects in van der Waals layered β-In2Se3 were studied by means of ab-erration-corrected scanning transmission electron microscopy combined with first-principles calculations.There are a significant amount of replacement-type stacking faults(RSFs)and slip-type stacking faults(SSFs)in 2H β-In2Se3.Moreover,the 1T phase slip-type stacking fault(tSSF),which is thermodynamically prone to spontaneous formation,was observed in 2H β-In2Se3.However,only the SSF was observed as a high energy configuration in 3R β-In2Se3.The phase separation occurred between 2H and 3R β-In2Se3with a coherent stacking interface.In addition,nine potential stacking fault configurations ofβ-In2Se3 were con-structed,the corresponding stacking fault energies were calculated,and the causes of stacking faults were analyzed from an energetic perspective.Finally,the need for a classification term describing the stacking faults in van der Waals-like layered materials is pointed out.
万方数据
