Berlin 2018 – scientific programme

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HL: Fachverband Halbleiterphysik

HL 40: II-VI semiconductors

HL 40.4: Talk

Thursday, March 15, 2018, 11:45–12:00, EW 201

Second Harmonic Generation in ZnSe/BeTe Multiple Quantum Wells — •Andreas Farenbruch¹, Johannes Mund¹, Walter Warkentin¹, Dmitri Yakovlev¹, Manfred Bayer¹, and Andreas Waag² — ¹Experimentelle Physik 2a, Technische Universität Dortmund, 44221 Dortmund, Germany — ²Institute of Semiconductor Technology, University of Braunschweig, 38106 Braunschweig, Germany

ZnSe/BeTe multiple quantum wells with a type-II band alignment are studied by the nonlinear optical technique of second-harmonic generation (SHG). The sample has ten periods of 20 nm thick ZnSe well layers and 10 nm thick BeTe barriers grown on a GaAs substrate by molecular-beam epitaxy.

Resonances of quantum well exciton states are detected and identified. Application of a magnetic field in Voigt geometry up to 10 T reveals several resonances of magneto-excitons. These are identified by comparison with measurements on ZnSe bulk samples. The exciton signals show quadratic dependence of SHG intensity on magnetic field strength and the diamagnetic shift. Rotational diagrams of the SHG polarisation dependence are measured and compared to model calculations.