Articolo in rivista, 2022, ENG, 10.1016/j.materresbull.2021.111578

Coupling in quantum dot molecular hetero-assemblies

Dibenedetto C.N.; Fanizza E.; De Caro L.; Brescia R.; Panniello A.; Tommasi R.; Ingrosso C.; Giannini C.; Agostiano A.; Curri M.L.; Striccoli M.

Department of Chemistry, University of Bari ''Aldo Moro'', Via Orabona, 4, Bari, 70125, aDepartment of Chemistry, University of Bari ''Aldo Moro'', Via Orabona, 4, 70125 Bari, Italy, , Italy; Institute for chemical and physical processes of CNR (IPCF-CNR), Via Orabona, 4, Bari, 70125, bInstitute for chemical and physical processes of CNR (IPCF-CNR), Via Orabona, 4, 70125 Bari, Italy, , Italy; Institute of Crystallography of CNR (CNR-IC), Via Amendola, 122/O, Bari, 70125, cInstitute of Crystallography of CNR (CNR-IC), Via Amendola, 122/O, 70125 Bari, Italy, , Italy; Italian Institute of Technology (IIT), Via Morego 30, Genova, 16163, dItalian Institute of Technology (IIT), Via Morego 30, 16163 Genova, Italy, , Italy; Basic Medical Sciences, Neuroscience, and Sense Organs, University of Bari ''Aldo Moro'', Piazza Giulio Cesare, 11, Bari, 70124, eBasic Medical Sciences, Neuroscience, and Sense Organs, University of Bari ''Aldo Moro'', Piazza Giulio Cesare, 11, 70124 Bari, Italy, , Italy

The design of large-scale colloidal quantum dots (QDs) assemblies and the investigation of their interaction with their close environment are of great interest for improving QD-based optoelectronic devices' performances. Understanding the interaction mechanisms taking place when only a few QDs are assembled at a short interparticle distance is relevant to better promote the charge or energy transfer processes. Here, small hetero-assemblies formed of a few CdSe QDs of two different sizes, connected by alkyl dithiols, are fabricated in solution. The interparticle distance is tuned by varying the linear alkyl chain length of the bifunctional spacer from nanometer to sub-nanometer range. The crystallographic analysis highlights that the nearest surfaces involved in the linkage between the QDs are the (101) faces. The thorough spectroscopic investigation enables a sound rationalization of the coupling mechanism between the interacting nanoparticles, ranging from charge transfer/wavefunction delocalization to energy transfer, depending on their separation distance.

Materials research bulletin 146

Keywords

Colloidal quantum dots, Hetero-assembly, Dithiol, time-resolved photoluminescence, coupling, Wavefunction Delocalization

CNR authors

Fanizza Elisabetta, Agostiano Angela, Curri Maria Lucia, Giannini Cinzia, De Caro Liberato, Striccoli Marinella, Ingrosso Chiara, Panniello Annamaria

CNR institutes

IC – Istituto di cristallografia, IPCF – Istituto per i processi chimico-fisici