Порівняльні оптичні та енергетичні характеристики екситонів у водних розчинах та твердих плівках квантових точок

• Дата: 2025
• Автори: Bondar, N.V., Piryatinski, Yu.P., Tverdochlibova, O.V.
• Формат: Стаття
• Мова: English; Ukrainian
• Опубліковано: Publishing house "Academperiodika" 2025
• Теми: Стоксiв зсув; квантова точка; енергiя збудження; екситон; ZnSe
• Онлайн доступ: https://ujp.bitp.kiev.ua/index.php/ujp/article/view/2023557
• Назва журналу: Ukrainian Journal of Physics

The results of studies of colloidal solutions of ultra-small ZnSe quantum dots (QDs) stabilized by short thioglycerol molecules and their dense films, which constitute the material basis of optoelectronic structures, are reported. A comparison of the results obtained for the solutions and the films makes it possible to better understand the transformation of corresponding optical characteristics during the transition from a system of non-interacting particles in the solution to a system with strong interaction between QDs. Delocalization of excitons and hybridization of their wave functions create a new set of QD energy states in the films, which govern the transport and optical properties of the latter. A substantial red shift between the absorption spectra of the solution and the film has been revealed, the nature of which is determined by strong interaction among the QDs. The researched dynamic characteristics showed that the time of the exciton excitation energy transfer in the films of ZnSe DQs with strong interaction can be subnanosecond (≈610 ps) and dominate over the time of internal exciton relaxation into in-gap, surface, and defect states of charge carriers.