کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5399405 | 1505905 | 2014 | 5 صفحه PDF | دانلود رایگان |
- Evidence of shell to core carrier transfer is observed via photoluminescence.
- A rate equation model was modified to account for the carrier transfer.
- Analysis showed that the carrier transfer is more favored at temperatures >90Â K.
We report on the shell-to-core carrier-transfer in GaAs/Al0.1Ga0.9As core-shell nanowires grown on Si(1Â 0Â 0) substrates via molecular beam epitaxy. The nanowires are dominantly zincblende and are tilted with respect to the substrate surface. Photoluminescence (PL) excitation spectrosocopy at 77Â K revealed an abrupt increase in the GaAs PL intensity at excitation above the Al0.1Ga0.9As shell bandgap which is attributed to shell to core carrier-transfer. More carriers from the Al0.1Ga0.9As transfer to the GaAs at T>90Â K, as observed in the time-resolved PL and temperature dependence of the relative PL intensities of GaAs and Al0.1Ga0.9As due to the ionization of the traps within the Al0.1Ga0.9As. Using a coupled rate equation model that takes into account shell to core carrier-transfer, the average recombination time constants of Al0.1Ga0.9As shell Ïrec,s=400Â ps (580Â ps) and GaAs core Ïrec,c=600Â ps (970Â ps) were obtained from the time-resolved PL at 300Â K (77Â K). Carrier-transfer time constants ÏCT=50Â ps (55Â ps) at 300Â K (77Â K) were also obtained.
Journal: Journal of Luminescence - Volume 155, November 2014, Pages 27-31