Стаціонарна спектроскопія та субнаносекундний резонансний перенос енергії екситонного збудження водних розчинів та плівок нанокристалів ZnSe

• Дата: 2022
• Автори: Bondar, N.V., Brodyn, M.S., Piryatinski, Yu.P., Matveevskaya, N.A.
• Формат: Стаття
• Мова: English; Ukrainian
• Опубліковано: Publishing house "Academperiodika" 2022
• Теми: exciton excitation energy; exciton; ZnSe; nanocrystal; енергiя екситонного збудження; екситон; нанокристал
• Онлайн доступ: https://ujp.bitp.kiev.ua/index.php/ujp/article/view/2022499
• Назва журналу: Ukrainian Journal of Physics

Densely packed solid films of semiconductor nanocrystals (NCs) demonstrate specific optoelectronic properties owing to the strong quantum interaction between the NCs and the hybridization of exciton orbitals. This fact opens ways for creating new artificial light-harvesting complexes and photovoltaic structures with the spatial separation of electrons and holes. This work was aimed at the study of colloidal solutions and solid films of thioglycerol-stabilized ZnSe NCs by measuring their steady-state and time-resolved optical spectra. Relaxation and recombination of excitons via the surface and defect states of electrons and holes were found to prevail in NC solutions, whereas the quantum (internal) channel exciton relaxation dominates in NC films, which, according to the results of time-resolved measurements of photoluminescence spectra, is associated with the rapid (sub-nanosecond) transfer of exciton excitation energy in the films from smaller NCs to larger ones. Furthermore, intragap exciton states of two types were revealed in small ZnSe NCs after the oxidation and hydroxylation of their surface, as well as their unusual “dependence” on the NC size.