Revisiting the “In-clustering” question in InGaN through the use of aberration-corrected electron microscopy below the knock-on threshold
The high intensity of light emitted in In[subscript x]Ga[subscript 1−x]N/GaN heterostructures has been generally attributed to the formation of indium-rich clusters in In[subscript x]Ga[subscript 1−x]N quantum wells (QWs). However, there is significant disagreement about the existence of such cluste...
| Main Authors: | , , , , |
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| Other Authors: | |
| Format: | Article |
| Language: | en_US |
| Published: |
American Institute of Physics (AIP)
2013
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| Online Access: | http://hdl.handle.net/1721.1/79641 |
| Summary: | The high intensity of light emitted in In[subscript x]Ga[subscript 1−x]N/GaN heterostructures has been generally attributed to the formation of indium-rich clusters in In[subscript x]Ga[subscript 1−x]N quantum wells (QWs). However, there is significant disagreement about the existence of such clusters in as-grown In[subscript x]Ga[subscript 1−x]N QWs. We employ atomically resolved CS-corrected scanning transmission electron microscopy and electron energy loss spectroscopy at 120 kV—which we demonstrate to be below the knock-on displacement threshold—and show that indium clustering is not present in as-grown In[subscript 0.22]Ga[subscript 0.78]N QWs. This artifact-free, atomically resolved method can be employed for investigating compositional variations in other In[subscript x]Ga[subscript 1−x]N/GaN heterostructures. |
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