کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5366355 | 1388347 | 2006 | 4 صفحه PDF | دانلود رایگان |
The photoluminescence spectra of InAs quantum dots (QDs) embedded into four types of InxGa1âxAs/GaAs (x = 0.10, 0.15, 0.20 and 0.25) multi quantum well MBE structures have been investigated at 300 K in dependence on the QD position on the wafer. PL mapping was performed with 325 nm HeCd laser (35 mW) focused down to 200 μm (110 W/cm2) as the excitation source. The structures with x = 0.15 In/Ga composition in the InxGa1âxAs capping layer exhibited the maximum photoluminescence intensity. Strong inhomogeneity of the PL intensity is observed by mapping samples with the In/Ga composition of x â¥Â 0.20-0.25. The reduction of the PL intensity is accompanied by a gradual “blue” shift of the luminescence maximum at 300 K as follows from the quantum dot PL mapping. The mechanism of this effect has been analyzed. PL peak shifts versus capping layer composition are discussed as well.
Journal: Applied Surface Science - Volume 252, Issue 15, 30 May 2006, Pages 5542-5545