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)
- 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
- Electronic and structural properties of the InP(100)(2x4) surface studied by core-level photoemission and scanning tunneling microscopy (2006)
- Surface Science
- High-resolution core-level photoemission study of Eu-induced (3x2)/(3x4) reconstruction on Ge(111) (2006)
- Physical Review B
- Scanning tunneling microscopy study of the Eu-induce Ge(111)-(3x2)/(3x4) reconstruction (2006)
- Physical Review B
- Structural and electronic properties of Bi-adsorbate-stabilized reconstructions on the InP(100) and GaAsN(100) surfaces (2006)
- Physical Review B
- Structural properties of Bi-terminated GaAs(001) surface (2006)
- Surface Science
- Atomic and electronic properties of GaAs(100) and InAs(100) semiconductor surfaces. (2005) P. Laukkanen