Fig. 1: Charge transport measurement modes and characterizations of MXene samples.
a, Schematic of charge transport within the network of MXene flakes. The inter-crystallite charge carrier hopping (indicated by the dashed arrows) is revealed as the charge transport bottleneck, limiting the overall charge conduction between electrodes. b, Scheme for ultrafast OPTP experiments to characterize the intra-MXene flake transport of charge carriers. Inset: the formation of a large polaron, in which a conduction electron is dressed by lattice deformations extending over several lattice constants. c, XRD spectra of Nb4AlC3 MAX (the mother compounds) and resultant Nb4C3Tx after etching. Inset: the crystal structure of Nb4C3Tx MXene. d, Raman spectrum of delaminated Nb4C3Tx MXene. e, TEM image of Nb4C3Tx MXene. Inset: corresponding SAED pattern, which shows the high crystallinity and hexagonal symmetry of the crystal lattice.
