Abstract
The use of the high-temperature-annealed self-buffer layer (HITAB) enabled to observe free
A
-and
B
-exciton emissions at
9
K
from ZnO heteroepitaxial films grown by the sputtering epitaxy method using a helicon-wave-excited plasma on uniaxially nearly lattice-matched
(
11
2
¯
0
)
Al
2
O
3
substrates. The result was correlated with a twofold decrease in the densities of threading dislocations having both the screw and edge components, according to the dislocation concealing in ZnO HITAB due to lateral mass transport of low-temperature deposited ZnO nanocrystalline grains during high temperature annealing.