Figure 2
From: Realizing a SnO2-based ultraviolet light-emitting diode via breaking the dipole-forbidden rule
Structural characterizations of nanostructure-engineered SnO2 thin films. (a) X-ray diffraction patterns of as-grown, 400, 600 and 800 °C annealed SnO2 thin films. The appearance of (110), (101) and (211) diffraction peaks after annealing indicates that the as-grown amorphous SnO2 thin films have been gradually crystallized. The reference powder diffraction data is also presented. (b) Raman spectra of the as-grown and the annealed SnO2 thin films. The A1g mode is enhanced and shifts to higher wave numbers with the increasing annealing temperature, suggesting enhanced crystallization. (c) High-resolution transmission electron microscope image of the SnO2 film annealed at 400 °C, showing nanocrystals embedded in the amorphous SnO2 matrix. (d) Magnified image of the nanocrystal marked in (c). (e) Corresponding selected area electron diffraction pattern taken on the 400 °C annealed sample.
