The photoluminescence and stimulated emission characteristics of two types of periodically polarity-inverted ZnO grating structures have been investigated in detail. Strong photoluminescence in the step regions is observed for all the samples. However, electron-hole plasma emission is observed only for one type of sample consisting of Zn-polar ZnO/CrN and O-polar ZnO/Cr2 O 3 layers. Moreover, strong stimulated emission occurs only in the Zn-polar layers. These optical phenomena have been discussed in terms of the diffusion of excitons and local crystal quality.
Bibliographical noteFunding Information:
This research was supported by WCU (World Class University) Program through National Research Foundation of Korea funded by the Ministry of Education, Science and Technology (Grant No. R31-2008-000-10075-0).
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