Linear polarized photoluminescence from GaN quantum dots imbedded in AlN matrix
2010 (English)Conference paper (Refereed)
We report microphotoluminescence studies of GaN/AlN quantum dots grown along the (0001) crystal axis by molecular-beam epitaxy on sapphire substrates. To obtain quantum dots with different density and size a nominal GaN coverage was varied from 1 to 4 monolayers. The highest density of quantum dots was about 1011 cm-2, so about 103 quantum dots was excited in experiments. We found that the photoluminescence intensity of a sample with the smallest amount of deposited GaN decreases in more than two orders of magnitude under continuous-wave laser exposure during about 30 minutes and then it remains stable. The photoluminescence intensity of the rest samples was time-independent quantity. The emission band of the former sample exhibits a prominent linear polarization along the growth plane. We assume that the quite high degree of polarization can be due anisotropy of strain and/or shape of the quantum dots formed near dislocations which act also as recombination centers causing photoluminescence quenching.
Place, publisher, year, edition, pages
2010. 2227-2229 p.
IdentifiersURN: urn:nbn:se:liu:diva-62206DOI: 10.1002/pssc.200983464OAI: oai:DiVA.org:liu-62206DiVA: diva2:371798
8th International Conference on Nitride Semiconductors (ICNS6), Nov 2009, Jeju, Korea