Photoluminescence studies of quantum-well structures in pulsed magnetic fields

Abstract

Magneto-photoluminescence spectroscopy at low temperatures has proved to be a powerful technique for investigating the electronic states of quantum well-type semiconductor heterostructures and offers a complimentary tool to electrical transport studies. We have established a magneto-optical facility at NHMFL-LANL and have undertaken a comprehensive investigation of magneto-excitonic and Landau transitions in a large variety of undoped and doped quantum-well structures. Fiber optic probes are used to switch between steady state (to 18 T) and pulsed (to 65 T) magnetic fields applied perpendicular (Faraday geometry) and parallel (Voigt geometry) to the growth axis of the 2D layers. The pulsed field mode requires that the spectroscopic data acquisition to be obtained in 1–2 ms in the `flat-top' region at the peak of the field. A broad range of samples have been investigated in pulsed magnetic fields as a function of temperature, sample geometry, and high pressure. Examples include single and coupled double quantum wells, modulation-doped quantum wells, and single interface heterojunction structures.