Surface potential effect on excitons in AlGaN/GaN quantum well structures
2013 (English)In: Applied Physics Letters, ISSN 0003-6951, E-ISSN 1077-3118, Vol. 102, no 8Article in journal (Refereed) Published
AlGaN/GaN quantum well (QW) heterostructures grown by metalorganic chemical vapor deposition on sapphire and on free-standing GaN substrates have been studied by temperature dependent time-resolved photoluminescence. A dominant contribution of the exciton radiative lifetime is observed in homoepitaxial samples even at enhanced temperatures up to 100 K. The QW-related emission is found to be more sensitive to the near surface built-in electric field in the homoepitaxial samples, revealed as a red shift of the QW exciton energy with decreasing the cap layer thickness. Absence of such shift in the heteroepitaxial samples suggests, assuming a surface potential of 0.5 eV, an increased polarization field due to residual compressive stress.
Place, publisher, year, edition, pages
American Institute of Physics (AIP) , 2013. Vol. 102, no 8
Engineering and Technology
IdentifiersURN: urn:nbn:se:liu:diva-90763DOI: 10.1063/1.4793568ISI: 000315597000049OAI: oai:DiVA.org:liu-90763DiVA: diva2:614686
Funding Agencies|Swedish Research Council (VR)||Swedish Energy Agency||Swedish Governmental Agency for Innovation Systems (VINNOVA)||2013-04-052013-04-052015-09-22