HRUBÁ, D. Strukturní a elektronické vlastnosti heteromolekulárních vrstev na povrchu kovů [online]. Brno: Vysoké učení technické v Brně. Fakulta strojního inženýrství. 2025.

Posudek vedoucího

Procházka, Pavel

Daniela Hrubá ve své diplomové práci zkoumala růst, strukturu a vlastnosti druhé vrstvy molekul hexamethoxytriphenylenu (HMTP) na předem připravených vrstvách plně deprotonovaných molekul 1,3,5-tris(4-karboxyphenyl)benzenu (BTB) na kovovém povrchu Ag(111). Komplexní experimenty probíhaly převážně v laboratořích CEITEC za podmínek ultravysokého vakua (UHV) a zahrnovaly nízkoenergiovou elektronovou mikroskopii (LEEM), rastrovací tunelovou mikroskopii (STM) a rentgenovou fotoelektronovou spektroskopii (XPS). Studentka pracovala samostatně a velmi aktivně se zajímala o danou problematiku. Naučila se samostatně používat veškeré potřebné experimentální techniky. Pozitivně také hodnotím její účast na měření elektronických vlastností na synchrotronu (Elettra, Terst, Itálie), kde se podílela jak na měření, tak i na následném zpracování dat použitých v této diplomové práci. Veškeré cíle práce byly splněny a diplomovou práci doporučuji k obhajobě. Hodnotím výborně.

Posudek oponenta

Redondo, Jesús

The researcher has produced an original work on the growth and characterization of BTB and HMTP overlayers on Ag(111). The work successfully reproduces previous literature results, with higher quality data in several instances, and builds on it with novel outputs by growing and characterizing a HMTP/BTB/Ag(111) heterostructure. A more detailed analysis of the main points of the text follows: Introduction: There is a good overview of the fundamental physics that govern surface-molecule and molecule-molecule interactions with respect to band theory for solids and organic semiconductors. The researcher showcases the different adsorption scenarios for physisorption, chemisorption and band alignment, which is key to understand the experimental procedures and data interpretation carried out in this dissertation and found in the literature. As a note of caution, I would like to mention that not all charged states of a molecule are formally a polaron; a polaron is a quasiparticle resulting from a charged state coupled with its own lattice distortion. The introduction has a proper funnel structure from a general overview of the governing physics to specific case studies found in the literature. The techniques are well described although some more references could be included.  Overall objective 1) is completely fulfilled. Experimental: The researcher showcases the growth and characterization of three systems: BTB overlayer on Ag(111), HMTP overlayer on Ag(111) and HMTP on BTB on Ag(111). Care is taken in the investigation of the thermal-induced deprotonation of BTB molecules which change their arrangement on the surface. The characterization is done by LEEM/STM at the CEITEC instruments and by XPS at Elettra Synchrotron.  The characterization by LEEM shows the evolution of the molecular films with the deposition rate and/or annealing temperature. I find the researcher extracts all the possible information from the data, i.e. the analysis of the adsorption geometry and overlayer structure of the molecules. The LEEM data is supported by synchrotron XPS analysis of the C and O 1s lineshape providing a reasonable interpretation of the components identified in the spectra, and how they evolve with the deposition time or annealing. Lastly RT-STM measurements complements in the real space the reciprocal space information from LEEM. The specific beamline where the XPS was measured is not explicitly mentioned in the text, although one can gather is the MSB from the references. Important information such as the energy resolution, undulator vs bending magnet... is not found easily in the text. The description of the growth methodology and data analysis is sufficient to probe the films on Ag(111) investigated at Elettra and CEITEC are equivalent, however obtaining reference lab-source XPS at CEITEC or LEED images at Elettra would strengthen this point. I consider the experimental section demonstrates the researcher widely fulfils the objectives 2)-5). I give this thesis a grade A (maximum).

eVSKP id 166587