Raman scattering as a tool to characterize semiconductor crystals, thin layers, and low-dimensional structures containing transition metals

Abstract

Raman scattering is well known as an efficient, nondestructive experimental method to study a variety of physical properties of semiconductors. The sensitivity of modern Raman spectroscopy is illustrated by several results obtained for semiconductor bulk crystals, thin layers, or low-dimensional structures, containing selected transition metals. Among examples of Raman scattering data are detection of precipitates, a study of the influence of strain on phonon and magnon frequencies, and a search for magnetic excitations or for new phenomena, characteristic of low-dimensional structures are described. The presented examples concern a few materials, which attract today or have attracted in the past a lot of attention. This selection is limited to Mn and Co impurities and to such well-known semiconductor materials as MnTe, (Ga,Mn)As, ZnO, and ZnTe. Comparison of the efficiency of Raman scattering on LO phonons (bottom right) with the PL efficiency for a semiconductor superlattice (upper left). The PL contribution to the total intensity due to the Cd0.88Zn0.12Te substrate is also shown.