• Właściwości spektralne i fotofizyczne cząsteczek donorowo-akceptorowych
• Wiązania wodorowe w stanach elektronowo wzbudzonych i ich rola w procesach dezaktywacji
• Efekt rozpuszczalnikowy w badaniach spektralnych i fotofizycznych

Najważniejsze publikacje:

1. E. Krystkowiak, Chapter 1: Effect of Solute–Solvent Hydrogen-Bonding on Spectral and Photophysical Properties of Aromatic Probes, K.-L. Han, G.-J. Zhao, ed., Hydrogen-Bonding Research in Photochemistry, Photobiology, and Optoelectronic Materials, World Scientific, New Jersey, 2019
2. E. Krystkowiak, A. K. Przybył, M. Bayda-Smykaj, J. Koput, A. Maciejewski, Spectral and photophysical properties of cytisine in acetonitrile – Theory and experiment, Spectrochim. Acta A, 203 (2018) 375-382
3. E. Krystkowiak, R. A. Bachorz, J. Koput, Ground and excited state hydrogen bonding effects of 6-aminocoumarin in water: An ab initio study, Dyes Pigments, 112 (2015) 335-340
4. E. Krystkowiak, K. Dobek, A. Maciejewski, Intermolecular hydrogen-bonding effect on spectral and photophysical properties of 6-aminocoumarin in protic solvents, Photochem. Photobiol. Sci., 12 (2013) 446-455
5. E. Krystkowiak, J. Koput, A. Maciejewski, Hydrogen bond effects in the ground and excited singlet states of 4H-1-benzopyrane-4-thione in water – theory and experiment, Phys. Chem. Chem. Phys., 14 (2012) 8842-8851
6. E. Krystkowiak, A. Maciejewski, Changes in energy of three types of hydrogen bonds upon excitation of aminocoumarins determined from absorption solvatochromic experiments, Phys. Chem. Chem. Phys., 13 (2011) 11317-11324
7. A. Maciejewski, E. Krystkowiak, J. Koput, K. Dobek, Influence of Hydrogen Bonds and Nonspecific Interactions on the Spectral and Photophysical Properties of the Excited Singlet States of 4-Aminophthalimide (4-AP) in Amine Solution, ChemPhysChem, 12 (2011) 322-332
8. E. Krystkowiak, K. Dobek, A. Maciejewski, Origin of the strong effect of protic solvents on the emission spectra, quantum yield of fluorescence and fluorescence lifetime of 4-aminophthalimide. Role of hydrogen bonds in deactivation of S₁-4-aminophthalimide, J. Photochem. Photobiol. A: Chem., 184 (2006) 250-264