Light-induced reconfiguration of dielectric in ultra-thin ...

NSF DMR-1720139
2019

Improving the Ambient
Stability of Chemically
Reactive 2D Materials
IRG-1, Northwestern University MRSEC

The vast majority of work on two-dimensional (2D)
materials has been limited to the few systems that are
stable in ambient conditions. However, hundreds of
additional 2D materials are highly reactive chemically
and thus require passivation schemes to enable study
and use in real-world settings. Among those
chemically reactive 2D materials, indium selenide
(InSe) is of particular interest due to its exceptional
charge carrier mobility and strong optical response. To
enable ambient processing and study of InSe, NUMRSEC IRG-1 has developed a mixed-dimensional
organic/inorganic passivation scheme based on nmethyl-2-pyrrilodone (NMP) seeded atomic layer
deposited (ALD) alumina that provides a pinhole-free
encapsulation layer that preserves the intrinsic
electronic properties of the underlying InSe. Since ALD
is a highly scalable process, this work will accelerate
ongoing efforts to integrate InSe nanosheets into
electronic and optoelectronic technologies

Nano Letters, 18, 7876-7882 (2018).

A

B

C

D

(A,B) Indium selenide (InSe) nanosheets are susceptible
to deleterious oxidation, leading to increases in
thickness when comparing atomic force microscopy
images (A) before and (B) after 3 days of ambient
exposure. (C,D) In contrast, InSe that has been
passivated with a hybrid organic/inorganic encapsulation
layer remains invariant (C) before and (D) after ambient
exposure.