Laboratory Website : lab30.infim.ro
Head of Laboratory : Dr. Valeriu Moldoveanu
There are 3 reseach groups in the laboratory of Nanoscale Condensed Matter Physics: SITSC-XESD team ( Surfaces, interfaces, thin films and single crystals. X-ray / electron spectroscopies and diffraction), Si- and Ge –based nanomaterials and Nanostructures team and the Theoretical Physics group.
The main activities of the SITSC-XESD group are centred on the development and complex studies of new materials, heterostructures, surfaces and interfaces. The group utilizes and maintains several widely used installations of NIMP: (i) a surface and interface science cluster composed by a molecular beam epitaxy (MBE), a scanning tunneling microscopy (STM) and a spin- and angle-resolved photoelectron spectroscopy (SARPES). A non-negligible amount of activity is dedicated to the development of analysis methods, starting from the theory of quantitative assessment to the adjustment of the experimental conditions. The group also provides unique expertise at national level in two very demanded fields: X-ray diffraction and X-ray photoelectron spectroscopy. Also, this is practically the unique group in the country concentrated on surface and interface science, working in real ultrahigh vacuum (UHV, 10-10 to 10-11 mbar). An MBE setup is installed and works currently.
The X-ray diffraction expertise is also boosted by novel developments in the XRD basic theory and data analysis, often implemented in widely used XRD analysis codes, which emerged also from the SITSC-XESD group.
The Si- and Ge –based nanomaterials team is working in the field of nanostructured semiconductors with applications in nanoelectronics, photovoltaics and sensors. The group studies:
- Films of Si nanodots embedded in amorphous SiO2 matrix: (i) preparation; (ii) investigation of microstructure, electrical transport, phototransport, and photoluminescence with the aim of capturing quantum confinement effects; (iii) modelling of nanoparticle energy structure.
- GeSiO-based nanostructures: (i) preparation of Ge nanoparticles embedded in a-SiO2 matrix, by magnetron sputtering and sol-gel methods; (ii) investigation of electrical behaviour and phototransport (experiment and modelling), photoluminescence and Hall effect.
- Electrical processes in carbon nanotubes based structures.
- Percolation phenomena: evidenced in carbon nanotubes based structures, Si nanodots embedded in amorphous SiO2 matrix and nanocrystalline porous Si.
- Trapping phenomena in Si-based nanostructures: stress-induced traps.
- The Theoretical Physics Group studies quantum transport phenomena in mesoscopic systems and provides phenomenological models and reliable descriptions of various effects observed in transport measurements.The main research topics cover several timely and challenging issues of mesoscopic transport: the transient transport regime in nano-devices, the mesoscopic Kondo and Fano-Kondo effects, controlled and intrinsic dephasing in mesoscopic interferometers, Coulomb drag and quantum ratchet effects in parallel quantum dots, spin interference in Rashba rings.