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Photoluminescence scanning on InAs/InGaAs quantum dot structures |
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| Authors: | M Dybiec S Ostapenko JL Casas Espinola KJ Malloy |
| Institution: | a University of South Florida, 4202 E Fowler Ave, Tampa, FL 33620, USA b ESFM-National Polytechnic Institute, Ed. 9, Mexico DF 07738, Mexico c CHTM at University New Mexico, Albuquerque, NM 87106, USA |
| Abstract: | The photoluminescence spectra of InAs quantum dots (QDs) embedded into four types of InxGa1−xAs/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 InxGa1−xAs 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 ≥ 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. |
| Keywords: | 78 67 &minus n 78 30 &minus j 78 55 &minus m |
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