Abstract

TAPIA-RODRIGUEZ, Lucy Estefanía; GUEVARA-MACIAS, Liliana Estela; LASTRAS-MARTINEZ, Alfonso  and  LASTRAS-MARTINEZ, Luis Felipe. Fabrication and characterization of quantum wells for the study of light-matter interaction. CienciaUAT [online]. 2023, vol.17, n.2, pp.6-23.  Epub June 26, 2023. ISSN 2007-7858.  https://doi.org/10.29059/cienciauat.v17i2.1737.

Quantum Wells are the basis for a great variety of electronic devices such as leds, lasers, photodetectors and modulators. Their optoelectronic properties depend on their chemical composition and the thickness of each layer. Therefore, a precise control during their growth is needed. This work has the objective of presenting the epitaxial growth of coupled and uncoupled asymmetric AlGaAs/GaAs/AlGaAs quantum wells and their characterization using optical techniques such as reflectance anisotropy spectroscopy (RAS) and photoluminescence (PL). An experimental study of the different interactions between the confined levels of energy in coupled quantum wells was carried on. This kind of structures is of special interest because they allow the formation and observation not only of direct excitons and trions inside a single quantum well, but of indirect excitons and trions, which are only formed by electrons of one quantum well and holes of the neighbor quantum well (IntraQW transitions). Three intrinsic quantum wells based on gallium arsenide (GaAs) were grown by molecular beam epitaxy (MBE), one single QW and a pair of coupled asymmetric QWs. The effect of breaking symmetry (from de D2d a C2v) on the spintronic properties of the structure was observed by RAS and PL measurements at ~ 30 K. The main techniques and methods for the growth of intrinsic quantum wells were established, which are the basis for the creation of devices with more complex structures. The use of spectroscopic techniques for the study of quantum wells allowed the demonstration of the presence of optical anisotropies that influence the behavior of exciton’s spins at quantum wells.

Keywords : quantum well; spectroscopy; excitons.

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