Pekka Laukkanen
peklau@utu.fi |
surface science; semiconductors, surface passivation, film growth
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 interface
between surface science and semiconductor technology, trying to improve interconnection and collaboration between these fields. His expertise area
includes photoelectron spectroscopy, scanning tunneling microscopy, electron
diffraction, surface passivation, interface defects, and semiconductor technology. Laukkanen has published
130 refereed articles, four book chapters, and three patents.
We have investigated surface properties: chemical, electronic, and structural ones of semiconductor crystals including silicon (Si), germanium (Ge), and III-V compound semiconductors (e.g. GaAs, GaN, InAs, InP) by means of electron diffraction (LEED, RHEED), scanning tunneling microscopy and spectroscopy (STM/STS), and photoelectron spectroscopy (including synchrotron sources). One goal has been to develop the connection or collaboration between the surface science and the semiconductor technology disciplines. More recently we have focused on the question how to decrease surface-related electrical losses and malfunctions in various semiconductor-based devices like capacitors, sensors, solar cells, and transistors. We have tried to understand reasons for formation of defect levels in device surfaces and to find controlled methods to decrease the amount of defect levels.
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 (Kiinteän aineen sähköiset ominaisuudet)
- Semiconductors (Puolijohteet)
- Semiconductor spectroscopy (method course)
- Dimer-T3 reconstruction of the Sm/Si(100)(2x3) surface studied by high-resolution photoelectron spectroscopy and density functional theory calculations (2011)
- Physical Review B
- Oxidized In-containing III-V(100) surfaces: Formation of crystalline oxide films and semiconductor-oxide interfaces (2011)
- Physical Review B
- Properties of self-assembled Bi nanolines on InAs(100) studied by core-level and valence-band photoemission, and first-principles calculations (2011)
- Physical Review B
- Properties of the SiO2- and SiNx- capped GaAs(100) surfaces of GaInAsN/GaAs quantum-well heterostructures studied by photoelectron spectroscopy and photoluminescence (2011)
- Applied Physics Letters
- Surface core-level shifts on Ge(111)c(2x8): Experiment and theory (2011)
- Physical Review B
- Tin stabilized (1×2) and (1×4) reconstructions on GaAs(100) and InAs(100) studied by scanning tunneling microscopy, photoelectron spectroscopy, and ab initio calculations (2011)
- Surface Science
- Ultrathin (1x2)-Sn layer on GaAs(100) and InAs(100) substrates: A catalyst for removal of amorphous surface oxides (2011)
- Applied Physics Letters
- Ab initio and scanning tunneling microscopy study of an indium-terminated GaAs(100) surface: An indium-induced surface reconstruction change in the c(8x2) structure (2010)
- Physical Review B
- Atomic structure of Yb/Si(100)(2x6): Interrelation between the silicon dimer arrangement and Si 2p photoemission line shape (2010)
- Physical Review B
- Bismuth-stabilized c(2x6) reconstruction on a InSb(100) substrate: Violation of the electron counting model (2010)
- Physical Review B
- Contactless electroreflectance study of band bending in Be-doped GaInNAs/GaAs quantum wells: The origin of the enhancement of photoluminescence (2010)
- Applied Physics Letters
- Core-level shifts of the c(8x2)-reconstructed InAs(100) and InSb(100) surfaces (2010)
- Journal of Electron Spectroscopy and Related Phenomena
- Effects of (NH4)2S and NH4OH surface treatments prior to SiO2 capping on 1.3: GaInAsN/GaAs quantum well structures (2010)
- Applied Physics Letters
- Metamorphic growth of tensile strained GaInP on GaAs substrate (2010)
- Journal of Crystal Growth
- Picosecond pulse laser ablation of yttria-stabilized zirconia from kilohertz to megahertz repetition rates (2010)
- Applied Physics A
- Stability, structural, and electronic properties of atomic chains on Yb/Ge(111)3X2 studied by STM and STS (2010)
- Physical Review B
- Annealing of self-assembled InAs/GaAs quantum dots: a stabilizing effect of beryllium doping (2009)
- Applied Physics Letters
- 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