Phase-Engineering-Driven Enhanced Electronic and Optoelectronic Performance of Multilayer In₂Se₃ Nanosheets

Here, we report electronic and optoelectronic performance of multilayer In2Se3 are effectively regulated by phase engineering. The electron mobility is increased to 22.8 cm2 V–1 s–1 for β-In2Se3 FETs, which is 18 times higher than 1.26 cm2 V–1 s–1 of α-In2Se3 FETs. The enhanced electronic performance is attributed to larger carrier sheet density and lower contact resistance. Multilayer β-In2Se3 photodetector exhibits an ultrahigh responsivity of 8.8 × 104 A/W under 800 nm illumination, which is 574 times larger than 154.4 A/W of α-In2Se3 photodetector. Our results demonstrate phase-engineering is a valid way to tune and further optimize electronic and optoelectronic performance of multilayer In2Se3 nanodevices.