| Title: |
Optical and Magneto-Optical Properties of Donor-Bound Excitons in Vacancy-Engineered Colloidal Nanocrystals |
| Authors: |
Carulli, Francesco; Pinchetti, Valerio; Zaffalon, Matteo L; Camellini, Andrea; Rotta Loria, Silvia; Moro, Fabrizio; Fanciulli, Marco; Zavelani-Rossi, Margherita; Meinardi, Francesco; Crooker, Scott A; Brovelli, Sergio |
| Contributors: |
Carulli, F; Pinchetti, V; Zaffalon, M; Camellini, A; Rotta Loria, S; Moro, F; Fanciulli, M; Zavelani-Rossi, M; Meinardi, F; Crooker, S; Brovelli, S |
| Publication Year: |
2021 |
| Collection: |
Università degli Studi di Milano-Bicocca: BOA (Bicocca Open Archive) |
| Subject Terms: |
bound exciton; electronic doping; magneto-optic; nanocrystal quantum dot; spectro-electrochemistry; sulfur vacancy |
| Description: |
Controlled insertion of electronic states within the band gap of semiconductor nanocrystals (NCs) is a powerful tool for tuning their physical properties. One compelling example is II-VI NCs incorporating heterovalent coinage metals in which hole capture produces acceptor-bound excitons. To date, the opposite donor-bound exciton scheme has not been realized because of the unavailability of suitable donor dopants. Here, we produce a model system for donor-bound excitons in CdSeS NCs engineered with sulfur vacancies (VS) that introduce a donor state below the conduction band (CB), resulting in long-lived intragap luminescence. VS-localized electrons are almost unaffected by trapping, and suppression of thermal quenching boosts the emission efficiency to 85%. Magneto-optical measurements indicate that the VS are not magnetically coupled to the NC bands and that the polarization properties are determined by the spin of the valence-band photohole, whose spin flip is massively slowed down due to suppressed exchange interaction with the donor-localized electron. |
| Document Type: |
article in journal/newspaper |
| Language: |
English |
| Relation: |
info:eu-repo/semantics/altIdentifier/pmid/34260252; info:eu-repo/semantics/altIdentifier/wos/WOS:000679930400040; volume:21; issue:14; firstpage:6211; lastpage:6219; numberofpages:9; journal:NANO LETTERS; https://hdl.handle.net/10281/320162 |
| DOI: |
10.1021/acs.nanolett.1c01818 |
| Availability: |
https://hdl.handle.net/10281/320162; https://doi.org/10.1021/acs.nanolett.1c01818; https://pubs.acs.org/doi/abs/10.1021/acs.nanolett.1c01818 |
| Rights: |
info:eu-repo/semantics/openAccess ; license:Creative Commons ; license uri:http://creativecommons.org/licenses/by/4.0/ |
| Accession Number: |
edsbas.D181FAC |
| Database: |
BASE |