Berlin 2015 – scientific programme

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HL: Fachverband Halbleiterphysik

HL 93: III-V semiconductors (other than nitrides)

HL 93.7: Talk

Thursday, March 19, 2015, 17:15–17:30, EW 203

Impact of growth temperature on structural and optical properties of GaAs quantum structures grown on GaP (100) substrate — •S. Dadgostar¹, J. Schmidtbauer², T. Boeck², M. Rodríguez³, A. Torres³, J. Jiménez³, O. Martínez³, W. T. Masselink¹, and F. Hatami¹ — ¹Department of Physics, Humboldt-Universität zu Berlin, Newton-Str. 15, D-12489 Berlin, Germany — ²Leibniz-Institut für Kristallzüchtung, Max-Born-Str. 2, D-12489 Berlin, Germany — ³GdS-Optronlab, Dpto. Fisica Materia Condensada, Univ. de Valladolid, Edificio I+D, Paseo de Belén 1, 47011, Valladolid, Spain

We describe impact of growth temperature on structural and optical properties of self-assembled GaAs/GaP quantum structures grown using GS-MBE. Formation of quantum structures is driven by the 3.6% lattice mismatch between GaAs and GaP. 2.7-ML of GaAs was deposited at temperatures between 450 and 530C on GaP(100) and capped by 50 nm GaP. Then, GaAs layer was grown again at the same conditions for AFM measurements. Morphology of deposited GaAs changes with increasing growth temperature from quantum dots to dashes. The dots have a density of e11 cm-2, diameter and height of 19, and 1.1 nm, while the dashes have a density of 7.0 e10 cm-2, length, width, and height of 58, 18, and 2.1 nm. Cathodeluminescence measurements indicate that the emission spectra of all samples contain two peaks between 1.99 and 1.84 eV, which we attribute to the recombination in wetting layer and in dot/dash structures. The peak position changes for samples due to different geometry of quantum structures.