Laboratory of Photoluminescence
Excitonic fine structure splitting in quantum dots can be tuned by external uniaxial strain field (top; different irregularity factor are considered for distinct lines). The effect is attributed to the induced anisotropy of valence band effective mass tensor resulting to modified elongation of the hole wave functions (bottom). After Phys. Rev. B 83, 121302(R).
Vlastimil Křápek's primary area of interest is a theoretical and numeric modeling of various nanoscale systems, including metallic nanoparticles, semiconductor quantum dots, quantum dot molecules, and their complexes. He studied the interrelation between the structural, electronic, and optical properties of quantum dots as well as their tunability by external effects (electric, magnetic, and strain field). In collaboration with experimentalists he pursues technologically important goals to push the emission of InAs quantum dots to the infrared telecommunication wavelengths or to lower the excitonic fine structure splitting below the natural linewidth. Recently he turned his attention to the metallic particles hosting localized surface plasmon resonances. He is involved in the modeling of electron energy loss spectroscopy of plasmonic nanoparticles and interested in coupling of the plasmonic particles with quantum dots, focusing on the enhancement of their photoluminescence rate (Purcell effect). He coauthored 28 scientific papers to which over 200 references were made.