Berlin 2015 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 96: Poster III C (III-V Semiconductors incl. Nitrides)
HL 96.20: Poster
Donnerstag, 19. März 2015, 14:00–20:00, Poster B
External Pressure on GaN/GaInN Quantum Wells: Influence of Strain on Internal Fields — •Hendrik Kuhn1, Torsten Langer2, Jens Hübner1, Andreas Hangleiter2, and Michael Oestreich1 — 1Leibniz Universität Hannover, Institut für Festkörperphysik, Abteilung Nanostrukturen, Appelstrasse 2, D-30167 Hannover, Germany — 2Technische Universität Braunschweig, Institut für Angewandte Physik, Mendelssohnstrasse 2, D-38106 Braunschweig, Germany
Group III nitride based heterostructures are of strong interest since their versatile tunability in emission energy that is especially interesting for optical devices e.g. the blue LED [1]. However, as a piezoelectric material they contain an internal electric field that results in a small overlap of the wavefunctions of electron and hole and is the reason for a reduced quantum efficency. We examine GaN/InGaN quantum wells (QW) and apply external stress in order to vary the internal piezoelectric fields and thereby influence the optical properties of the QWs [2,3]. We measure time resolved photoluminescence and perform pump probe experiements on single and multiple GaN/InGaN QW under varied strain that is applied uniaxial and along the growth direction with a pressure cell. Additionally we measure the spin dynamics via Kerr rotation to gain information on the internal electric fields since the spin dephasing rate is directly related to the field via Rashba effect.
[1] Y. Nanishi, Nat. Photonics (2014). [2] S.L. Chuang and C.S. Chang, Semicond. Sci. Technol. 12, (1997). [3] A. Hangleiter et al., Phys. Status Solidi 216, (1999).