Figure 1
HRTEM analysis of GQDs and GQD solid sheet structures. (a) Spherical shaped GQDs with size around 5 nm from Z0 sample (b) spherical shaped GQDs with size around 10 nm from the Z1 sample (c) slab like GQD solid sheets in 100 nm size range from Z3 sample (d–e) slab like GQD solid sheets having average size about 1µm from Z5 and Z7 samples, respectively. The samples Z0, Z1 and Z3 are polycrystalline in nature, as revealed by the SAED pattern given as the inset of respective figures. The Z5 and Z7 samples are single crystalline in nature. (f) An example SAED pattern obtained from the Z7 sample. The double diffraction spots represented by the red line, in the single crystalline SAED pattern reveals the presence of twinning effect in the solid sheet samples.
