Fig. 3: Characterizations of 2DPI.
From: On-water surface synthesis of electronically coupled 2D polyimide-MoS2 van der Waals heterostructure
a An optical microscope image of the 2DPI film on a SiO2/Si substrate. b AFM image showing the monolayer features of the 2DPI. c ATR-FTIR spectroscopy of 2DPI shows the appearance of the imide C=O and the complete vanishing of the N-H stretch at ~3345 cm-1 from M1. d, e High-resolution XPS spectrum of the N1s region and the O1s region of 2DPI. f SAED pattern of the transferred monolayer 2DPI film.
