Raman spectroscopy of elementary excitations in semimagnetic semiconductor nanoparticles and nanostructures 


    In this project we shall investigate the optical properties of semimagnetic semiconductors (bulk and nano crystals and low dimensional structures) based on the lead, zinc, mercury and cadmium halchogenides, undoped and doped with the elements of the group III or transitional elements. In undoped alloys we propose investigation phonon properties and electronic structure (electron-phonon and plasmon-phonon interaction). In doped systems the effects connected with the existence of mixed valence of the impurity (DX and off centers) will be investigated as well as coupling of the electron continuum with the vibrational modes of the impurity, long-live relaxation processes and  persistent photoconductivity.

 Scientific aims of the joint project

    The main objective of this project is to develop the materials science of magnetic and semimagnetic semiconductors, which have good perspectives in spin-base electronic technologies, or spintronics. Interest in semimagnetic semiconductors oryginally arose from the so-colled "giant Zeeman effects" observed in excitonic levels. In this area, the giant Zeeman splittings are used to generate spin-resolved conductivity chanels in semiconductors. The resulting spin-polarized currents may provide new spin-based degrees of freedom to semiconductor devices that will increase the information content of a charge pulse, and could potentially introduce new functionalities having no analog in curent-based semiconductor technologies.

    We are going to reach a progress in each of above-mentioned directions, using various semiconductor materials, combining the essential properties by doping and variation of the composition of alloys. Our main materials are II-VI and  IV-VI diluted magnetic semiconductors (eg. CdMnTe, CdMnSe, CdMnS, ZnMnS, PbMnTe, HgMnTe and HgMnSe)  as well as   magnetic semiconductors (eg. EuGdTe, EuS) and nanostructered based on this materials.

    Investigation would be performed through the following topics:

1. Vibrational spectroscopy and photoluminescence of Cd1-xMnxS, Cd1-xMnxSe, Pb1-xMnxTe bulk single crystals.

2. Vibrational spectroscopy and photoluminescence of Cd1-xMnxS and Zn1-xMnxS nanocrystals and low dimensional structures.

3. Influence of doping with elements of III group (Ga and In) and transitional elements with unfilled d-orbital (Cr, Mn, Co, Ni) on optical and transport properties of the lead and mercury halchogenides.

First year:

Incorporating nanoparticles in dielectrics, to obtained embedded semiconductor dots in transparent materials.

Low temperature Raman and FIR spectroscopy measurements.

Second year:

Low temperature magnetic and photoluminescence measurements in strong magnetic fields.

Micro Raman spectroscopy at low temperature and high magnetic fields.

Benefit to both sides from this collaboration

1. Increase of knowledge of optical, magnetic  and transport properties of semimagnetic semiconductors as perspective materials for spintronics application.

2. More effective use of complementary methods and equipments , which exists in both institutions.

3. Establishment of closer cooperation important for strengthening of European Scientific knowledge (in perspective common applications for European grants).


Center for Solid State and New Materials :: Projects
Study of the orbital ordering in La1-xAxMn1-zBzO3 manganites 
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