TY - JOUR
T1 - Excitonic transitions in MBE grown h-GaN with cubic inclusions
AU - Strauf, Stefan
AU - Michler, Peter
AU - Gutowski, Jürgen
AU - Selke, Hartmut
AU - Birkle, Udo
AU - Einfeldt, Sven
AU - Hommel, Detlef
PY - 1998/6/15
Y1 - 1998/6/15
N2 - Undoped and magnesium doped MBE grown GaN epilayers on sapphire substrates show a particular variety of near-bandgap luminescent transitions. Despite the large lattice mismatch to the substrate, pronounced free- and bound-exciton transitions allow for an estimation of the excitonic binding energies. For the given thickness range (about 1 μm), we find an almost strain-relaxed situation with the main exciton transition energies well corresponding to the bulk values. On their low-energy side, we identify lines having been tentatively assigned to stacking fault excitons, and interface-related exciton transitions correlated to extended defects and/or dislocations in this spatial region. Evidence of cubic inclusions of a size up to 500 nm is doubtless given by observing sharp C-GaN related donor-bound exciton emission and respective structures in transmission electron microscope investigations.
AB - Undoped and magnesium doped MBE grown GaN epilayers on sapphire substrates show a particular variety of near-bandgap luminescent transitions. Despite the large lattice mismatch to the substrate, pronounced free- and bound-exciton transitions allow for an estimation of the excitonic binding energies. For the given thickness range (about 1 μm), we find an almost strain-relaxed situation with the main exciton transition energies well corresponding to the bulk values. On their low-energy side, we identify lines having been tentatively assigned to stacking fault excitons, and interface-related exciton transitions correlated to extended defects and/or dislocations in this spatial region. Evidence of cubic inclusions of a size up to 500 nm is doubtless given by observing sharp C-GaN related donor-bound exciton emission and respective structures in transmission electron microscope investigations.
KW - Cubic inclusions
KW - Dislocations
KW - Excitons in wurtzite GaN
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U2 - 10.1016/S0022-0248(98)00252-8
DO - 10.1016/S0022-0248(98)00252-8
M3 - Article
AN - SCOPUS:0032090812
SN - 0022-0248
VL - 189-190
SP - 682
EP - 686
JO - Journal of Crystal Growth
JF - Journal of Crystal Growth
ER -