Pekka Laukkanen
peklau@utu.fi |
surface science; semiconductors, surface passivation, film growth
Materials physics, semiconductor research, surfaces and interfaces
Pekka Laukkanen obtained his MSc degree in 2000 at Tampere University of Technology in the field of optoelectronics. He completed his PhD thesis in 2005 in the area of surface physics at University of Turku. He is now working at a boundary between surface science and semiconductor technology, trying to improve connection and collaboration between these two fields. His expertise area includes photoelectron spectroscopy, scanning tunneling microscopy, electron diffraction, surface passivation, interface defects, and semiconductor technology.
Our research group has investigated surface properties: chemical, electronic and structural ones of traditional semiconductor crystals including silicon (Si), germanium (Ge), and III-V compound semiconductors (e.g. GaAs, GaN, InAs, InP) by means of electron diffraction (LEED), scanning tunneling microscopy and spectroscopy (STM/STS), and photoelectron spectroscopy (including synchrotron sources). One goal has been to contribute bridging between the fields of surface science and the semiconductor technology. More recently we have focused on the question how to decrease surface-related electrical and optical losses in semiconductor-based devices like capacitors, sensors, solar cells, and transistors. We aim to understand reasons behind formation of defect levels in device surfaces and to find new methods to decrease the amount of defect levels. In order to measure opto-electrical properties, we have learned to manufacture simple devices in clean rooms.
Recently I have teched the following courses at the University of Turku:
- Phases and properties of materials (Aineen olomuodot ja ominaisuudet)
- Electrical properties of solids
- Semiconductors
- Semiconductor spectroscopy (method course)
- Core-level shifts of InP(100)(2x4) surface: Theory and experiment (2009)
- Surface Science
- Stability of rare earth metal atom induced (2x3) reconstructions on Si(100) surface (2009)
- Physical Review B
- The influence of As/III pressure ratio on nitrogen nearest-neighbor environments in as-grown GaInNAs quantum wells (2009) R. Kudrawiec, V.-M. Korpijärvi, P. Poloczek, J. Misiewicz, P. Laukkanen, J. Pakarinen, M. Dumitrescu, M. Guina, M. Pessa
- Ytterbium on vicinal Si(100): Growth and properties of the 2D wetting layer and the Yb silicide phase (2009)
- Surface Science
- A comparative study of the effect of applied As flux on the growth of GaAs / AlAs quantum wells.
Applied Surface Science (2008)- Applied Surface Science
- Anomalous Bismuth-Stabilized (2x1) Reconstructions on GaAs(100) and InP(100) Surfaces (2008)
- Physical Review Letters
- Bismuth-stabilized (2x1) and (2x4) reconstructions on the III-V(100) surfaces: A combined first-principles and photoemission and scanning-tunneling-microscopy study (2008)
- Physical Review B
- Formation of an ordered pattern of Bi nanolines on InAs(100) by self-assembly (2008)
- Applied Physics Letters
- Post-annealing of InGaAs / GaAs and InGaAsN / GaAs triple quantum-well structures with a modified proximity GaAs cap: A dramatic effect on the optical and structural properties (2008)
- Applied Physics Letters
- Suppression of annealing-induced In diffusion in Be-doped GaInNAs / GaAs quantum wells (2008)
- Applied Physics Letters
- Surface core-level shifts within complete screening: problems with pseudohydrogenated slabs (2008)
- Physical Review B
- Yb-induced (2x3) and (2x4) reconstructions on Si(100) studied by STM, high-resolution core-level photoelectron spectroscopy, and first-principles calculations (2008)
- Physical Review B
- A comparative study of clean and Bi-stabilized InP(100)(2 x 4) surfaces by the core-level photoelectron spectroscopy (2007)
- Surface Science
- Atomic and electronic structure of the Yb/Ge(111)-(3 x 2) surface studied by high-resolution photoelectron spectroscopy (2007)
- Physical Review B
- Atomic geometry and electronic properties of the Ge(111)2 x 1-Sb surface studied by scanning tunneling microscopy/spectroscopy and core-level photoemission. (2007)
- Surface Science
- High-resolution core-level photoemission study of Ge(111)2 x 1-Sb and Ge(111)(√3 x √3)R30º-Bi reconstructions (2007)
- Journal of Electron Spectroscopy and Related Phenomena
- Structural properties of Bi-stabilized reconstructions of GaInAs(100) surface (2007)
- Applied Physics Letters
- Surface core-level shift of Pd at the AgPd1-c (111) surface: Nonlinear subsurface effects. (2007)
- Surface Science
- Surface core-level shifts of GaAs(100)(2 x 4) from first principles. (2007)
- Physical Review B
- Application of regioregular polythiophene in spintronic devices: Effect of interface (2006)
- Applied Physics Letters



