Figures

Figure 1

The (0001) and (10 0) planes of sapphire.

Figure 2

PL spectra from the three epilayers. The spectra are displaced for clarity. The inset shows high spectral resolution temperature dependent spectra in the excitonic region from the 10° epilayer.

Figure 3

Low temperature PL and CL (15 keV) spectra from 10° epilayer.

Figure 4

Temperature dependent PL spectra from 10° epilayer.

Figure 5

20 µm x 20 µm AFM image of the surface of the 10° epilayer.

Figure 6

An SEM image and comparative CL images acquired at 15 keV from the 10° epilayer. The image acquired at 3.48 eV corresponds to D0X emission, where the donor is the silicon dopant. The image acquired at 3.41 eV corresponds to excitonic emission attributed to structural defects. The image acquired at 3.288 eV corresponds to DAP emission. The black scale marker corresponds to 10 µm.

© 1998 The Materials Research Society