Femtosecond carrier dynamics of Inx Ga1-x N thin films grown on GaN (0001): Effect of carrier-defect scattering
AuthorLioudakis, Emmanouil E.
Othonos, Andreas S.
SourceJournal of Applied Physics
Google Scholar check
MetadataShow full item record
Ultrafast carrier dynamics in ultrathin Inx Ga1-x N ternary alloys were investigated in detail, using femtosecond transient differential optical absorption measurements. Measurements were performed with probing wavelengths above and below the band edge of the materials. Furthermore, we performed a structural characterization by x-ray diffraction reciprocal space maps and we found that the alloys with the higher InN mole fraction (x=0.89 and x=0.43) present large lattice mismatch-strain relaxation whereas the lower InN content alloy was fully coherent with the underlying GaN (0001) layer. Our analysis showed that the observed nonradiative carrier dynamics was strongly related with the carrier-defect scattering of the materials. Our measurements in conjunction with the numerical analysis showed that when we excite these alloys with ultrashort laser pulses the background carrier concentration for In-rich InGaN samples participates to the photoexcited carrier relaxation process via carrier momentum scattering. For the higher InN content alloys (x=0.89 and 0.43) the relaxation times were short (0.4-1.4 ps) whereas for the full strained alloy (x=0.07) a slower nonradiative relaxation time (∼25 ps) was observed. Finally, the energy loss rate of this material (2.05±0.10 meVfs) as well as the optical phonon lifetime (44±2 fs) were extracted. © 2007 American Institute of Physics.
Showing items related by title, author, creator and subject.
Surface-related states in oxidized silicon nanocrystals enhance carrier relaxation and inhibit auger recombination Othonos, Andreas S.; Lioudakis, Emmanouil E.; Nassiopoulou, Androula Galiouna (2008)We have studied ultrafast carrier dynamics in oxidized silicon nanocrystals (NCs) and the role that surface-related states play in the various relaxation mechanisms over a broad range of photon excitation energy corresponding ...
Othonos, A.; Zervos, Matthew (2009)Carrier relaxation dynamics in tin nitride (SnxNy) nanowires have been investigated using femtosecond transient absorption spectroscopy. The nanowires were grown directly on quartz using chemical vapor deposition and had ...
Othonos, Andreas S.; Zervos, Matthew (2009)Carrier relaxation dynamics in tin nitride (SnxNy) nanowires have been investigated using femtosecond transient absorption spectroscopy. The nanowires were grown directly on quartz using chemical vapor deposition and had ...