Filip Tuomisto

Contingent Worker
Contingent Worker
T304 Dept. Applied Physics

My scientific research work focuses on the fundamental connection between macroscopic properties and atomic-level structure of materials. The methodology of choice is positron annihilation spectroscopy that is particularly suitable for lattice defect characterization in solids. The power of positron spectroscopies lies in (i) the selective sensitivity to open volume structures, (ii) the possibility of studying materials of any type (conductive, insulating, hard, soft, crystalline, or porous) and (iii) the possibility of direct comparison of theoretical calculations and experimental observations. My group is is one of the world’s leading teams in developing the methodology, instrumentation, applications and theory of positron annihilation spectroscopy of semiconductor materials and devices.

Full researcher profile


[email protected]


Positron annihilation spectroscopy


2016 Chevalier dans l’Ordre des Palmes Académiques

Decoration issued by the French government for distinguished academics.
Palkinto tai huomionosoitus urasta Teknillisen fysiikan laitos Jan 2016

2015 EspooAmbassador

Awarded by the city of Espoo based on activity in the scientific community and conference organization.
Palkinto tai huomionosoitus urasta Teknillisen fysiikan laitos Jan 2015


  • Complex Systems and Materials, Vierailija (opetus- ja tutkimushenkilöstö)


Open volume defects in ultra-thin TiO2 layers embedded in VMCO-like samples studied with positron annihilation spectroscopy

Afrina Khanam, Jonatan Slotte, Filip Tuomisto, Subhali Subhechha, Mihaela Popovici, Gouri Sankar Kar 2022 Journal of Applied Physics

Growth of highly conductive Al-rich AlGaN:Si with low group-III vacancy concentration

Abdullah S. Almogbel, Christian J. Zollner, Burhan K. Saifaddin, Michael Iza, Jianfeng Wang, Yifan Yao, Michael Wang, Humberto Foronda, Igor Prozheev, Filip Tuomisto, Abdulrahman Albadri, Shuji Nakamura, Steven P. DenBaars, James S. Speck 2021 AIP ADVANCES

Interplay of vacancies, hydrogen, and electrical compensation in irradiated and annealed n-type β-Ga2O3

A. Karjalainen, P. M. Weiser, I. Makkonen, V. M. Reinertsen, L. Vines, F. Tuomisto 2021 Journal of Applied Physics

Split Ga vacancies in n -type and semi-insulating β -Ga2O3single crystals

A. Karjalainen, I. Makkonen, J. Etula, K. Goto, H. Murakami, Y. Kumagai, F. Tuomisto 2021 Applied Physics Letters

In Situ Positron Annihilation Spectroscopy Analysis on Low-Temperature Irradiated Semiconductors, Challenges and Possibilities

Jonatan Slotte, Simo Kilpeläinen, Natalie Segercrantz, Kenichiro Mizohata, Jyrki Räisänen, Filip Tuomisto 2021 Physica Status Solidi (A) Applications and Materials Science

Split Ga vacancies

Filip Tuomisto, Antti Karjalainen, Ilja Makkonen 2021 Oxide-Based Materials and Devices XII

Defect-mediated metastability and carrier lifetimes in polycrystalline (Ag,Cu)(In,Ga)Se2 absorber materials

Andrew Ferguson, Rouin Farshchi, Pran K. Paul, Pat Dippo, Jeff Bailey, Dmitry Poplavskyy, Afrina Khanam, Filip Tuomisto, Aaron Arehart, Darius Kuciauskas 2020 Journal of Applied Physics

Effect of Mn and Mg dopants on vacancy defect formation in ammonothermal GaN

T. Heikkinen, J. Pavlov, T. Ceponis, E. Gaubas, M. Zając, F. Tuomisto 2020 Journal of Crystal Growth

Split Ga vacancies and the unusually strong anisotropy of positron annihilation spectra in β-Ga2 O3

Antti Karjalainen, Vera Prozheeva, Kristoffer Simula, Ilja Makkonen, Vincent Callewaert, Joel B. Varley, Filip Tuomisto 2020 Physical Review B


Antti Karjalainen, Vera Prozheeva, Ilja Makkonen, Christo Guguschev, Toni Markurt, Matthias Bickermann, Filip Tuomisto 2020 Journal of Applied Physics