Title Energy-level interpretation of carbazole derivatives in self-assembling monolayer /
Authors Grzibovskis, Raitis ; Aizstrauts, Arturs ; Pidluzhna, Anna ; Marcinskas, Mantas ; Magomedov, Artiom ; Karazhanov, Smagul ; Malinauskas, Tadas ; Getautis, Vytautas ; Vembris, Aivars
DOI 10.3390/molecules29091910
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Is Part of Molecules.. Basel : MDPI. 2024, vol. 29, iss. 9, art. no. 1910, p. 1-10.. ISSN 1420-3049
Keywords [eng] ionization energy ; photoelectron emission spectroscopy ; self-assembling monolayer ; work function
Abstract [eng] Energy-level alignment is a crucial factor in the performance of thin-film devices, such as organic light-emitting diodes and photovoltaics. One way to adjust these energy levels is through chemical modification of the molecules involved. However, this approach may lead to unintended changes in the optical and/or electrical properties of the compound. An alternative method for energy-level adjustment at the interface is the use of self-assembling monolayers (SAMs). Initially, SAMs with passive spacers were employed, creating a surface dipole moment that altered the work function (WF) of the electrode. However, recent advancements have led to the synthesis of SAM molecules with active spacers. This development necessitates considering not only the modification of the electrode's WF but also the ionization energy (IE) of the molecule itself. To measure both the IE of SAM molecules and their impact on the electrode's WF, a relatively simple method is photo-electric emission spectroscopy. Solar cell performance parameters have a higher correlation coefficient with the ionization energy of SAM molecules with carbazole derivatives as spacers (up to 0.97) than the work function of the modified electrode (up to 0.88). Consequently, SAMs consisting of molecules with active spacers can be viewed as hole transport layers rather than interface layers.
Published Basel : MDPI
Type Journal article
Language English
Publication date 2024
CC license CC license description