Skip to main content

Ultrafast and near-field spectroscopy

Our group has been working on ultrafast semiconductor spectroscopy since 1993. In our research, the main focus is on material and heterostructure properties critical for an efficient operation of photonic devices. Over the years, we have studied optically-detected carrier transport in InP- and GaN-based quantum well laser structures, ultrafast carrier trapping in implanted and heavily doped semiconductors (GaAs, InGaAs, InP, GaN), and carrier dynamics in self-assembled In(Ga)As quantum dots. By means of pump-probe technique, we have been refining the band structure of GaN and studying ultrafast hole self-trapping in b-Ga2O3. In the last decade, our scope of experimental research has been extended into scanning near-field optical microscopy (SNOM). Using our unique SNOM set-up, we are able to measure, in a single scan, maps of surface morphology, and photoluminescence spectra, polarization and dynamics. The set-up is being used to study carrier recombination, localization and transport in InGaN, AlGaN and their quantum wells.

Project leader:

Saulius Marcinkevicius
Saulius Marcinkevicius
professor +4687904192


  • Photoluminescence measurement setup
    Multimode scanning near-field optical microscope (SNOM) allowing to map surface morphology, photoluminescence (PL) intensity, linewidth, peak wavelength and polarization, and radiative and nonradiative recombination times. Operation temperature - 300 K; typical spatial resolution - 100 nm. PL excitation range - 220 to 1300 nm.
  • Time-resolved PL set-ups based on a streak camera and a time-correlated single photon counting. Temperature 3 - 300 K; temporal resolution 3 and 50 ps, respectively.
  • Dual colour pump-probe for differential transmission and reflection measurements. Temperature 3 - 300 K; spectral range 220-1300 nm, temporal resolution 200 fs.

Recent highlights:

  • Determination of the ultrafast hole self-localization time in beta-Ga2O3; Appl. Phys. Lett. 116, 132101 (2020).
  • Demonstration of a ballistic hole transport in GaN-based quantum well structures; Phys. Rev. B 101, 075305 (2020).
  • First high-resolution mapping of radiative and nonradiative recombination times in a semiconductor, (m-plane InGaN quantum well); Appl. Phys. Lett. 110, 031109 (2017).
  • Construction of a multimode SNOM set-up allowing to measure surface morphology, PL spectra in illumination and illumination-collection modes, and PL dynamics; ACS Photonics 5, No. 2, p. 528-534 (2018).
  • Demonstration of the importance of Fe excited states in Shockley-Read-Hall recombination in Fe-doped GaN; J. Appl. Phys. 119, 215706 (2016), Appl. Phys. Lett 109, 162107 (2016).

Recent publications:

  1. R. Yapparov, Y. C. Chow, C. Lynsky, F. Wu, S. Nakamura, J. S. Speck and S. Marcinkevičius, "Variations of light emission and carrier dynamics around V-defects in InGaN quantum wells," Journal of Applied Physics 128, 225703 (2020);
  2. R. Yapparov, C. Lynsky, S. Nakamura, J. S. Speck and S. Marcinkevičius, "Optimization of barrier height in InGaN quantum wells for rapid interwell carrier transport and low nonradiative recombination," Applied Physics Express 13, 122005 (2020);
  3. S. Marcinkevičius and J. S. Speck, "Ultrafast hole self-localization in β-Ga2O3," Applied Physics Letters 116, 132101 (2020);
  4. S. Marcinkevičius, R. Yapparov,L. Y. Kuritzky, S. Nakamura and J. S. Speck, "Low temperature carrier transport across InGaN multiple quantum wells: Evidence of ballistic hole transport," Physical Review B 101, 075305 (2020);
  5. A. C. Espenlaub, D. J. Myers, E. C. Young, S. Marcinkevičius, C. Weisbuch and J. S. Speck, "Evidence of trap-assisted Auger recombination in low radiative efficiency MBE-grown III-nitride LEDs," Journal of Applied Physics, 126, 184502 (2019);
  6. M. A. Bergmann, J. Enslin, R. Yapparov, F. Hjort, B. Wickman, S. Marcinkevičius, T. Wernicke, M. Kneissl and Å Haglund, "Electrochemical etching of AlGaN for the realization of thin-film devices," Applied Physics Letters, 115, 182103 (2019);
  7. S. Marcinkevičius,R. Yapparov, L. Y. Kuritzky, Y.-R. Wu, S. Nakamura, S. P. DenBaars and J. S. Speck, "Interwell carrier transport in InGaN/(In)GaN multiple quantum wells," Applied Physics Letters, 114, 151103 (2019);
  8. T. K. Uždavinys, S. Marcinkevičius, M. Mensi, L. Lahourcade, J.-F. Carlin, D. Martin, R. Butté and N. Grandjean, "Impact of surface morphology on properties of light emission in InGaN epilayers," Applied Physics Express, 11, 051004 (2018);
  9. R. Butté, L. Lahourcade, T. K. Uždavinys, G. Callsen, M. Mensi, M. Glauser, G. Rossbach, D. Martin, J.-F. Carlin, S. Marcinkevičius and N. Grandjean, “Optical absorption edge broadening in thick InGaN layers: random alloy atomic disorder and growth mode induced fluctuations,” Applied Physics Letters, 112, 032106 (2018);
  10. M. Mensi, R. Ivanov, T. K. Uždavinys, K. M. Kelchner, S. Nakamura, S. P. DenBaars, J. S. Speck and S. Marcinkevičius, "Direct measurement of nanoscale lateral carrier diffusion: toward scanning diffusion microscopy" ACS Photonics, 5, 528 (2018);

Current projects:

  • Mastering carrier dynamics to increase efficiency of blue and green LEDs, The Swedish Energy Agency, 2018-2022
  • Nanometre scale band potential fluctuations: an electron's perspective​, The Swedish Research Council, 2019-2022
Page responsible:Max Yan
Belongs to: Photonics
Last changed: Feb 08, 2021