RT Journal Article
T1 Probing surface states in C_60 decorated ZnO microwires: detailed photoluminescence and cathodoluminescence investigations
A1 Rodrigues, Joana
A1 Smazna, Daria
A1 Ben Sedrine, Nabiha
A1 Nogales Díaz, Emilio
A1 Adelung, Rainer
A1 Mishra, Yogendra K
A1 Méndez Martín, María Bianchi
A1 Correia, María R.
A1 Monteiro, Teresa
AB ZnO microwires synthesised by the flame transport method and decorated with C_60 clusters were studied in detail by photoluminescence (PL) and cathodoluminescence (CL) techniques. The optical investigations suggest that the enhanced near band edge recombination observed in the ZnO/ C_60 composites is attributed to the reduction of the ZnO band tail states in the presence of C_60. Well-resolved free and bound excitons recombination, as well as 3.31 eV emission, are observed with increasing amount of C_60 flooding when compared with the ZnO reference sample. Moreover, a shift of the broad visible emission to lower energies occurs with increasing C_60 content. In fact, this band was found to be composed by two optical centres peaked in the green and orange/ red spectral regions, presenting different lifetimes. The orange/ red band exhibits faster lifetime decay, in addition to a more pronounced shift to lower energies, while the peak position of the green emission only shows a slight change. The overall redshift of the broad visible band is further enhanced by the change in the relative intensity of the mentioned optical centres, depending on the excitation intensity and on the C_60  flooding. These results suggest the possibility of controlling/ tuning the visible emission outcome by increasing the C_60  amount on the ZnO surface due to the surface states present in the semiconductor. An adequate control of such phenomena may have quite beneficial implications when sensing applications are envisaged.
PB Royal Society Chemistry
SN 2516-0230
YR 2019
FD 2019-04-01
LK https://hdl.handle.net/20.500.14352/13615
UL https://hdl.handle.net/20.500.14352/13615
LA eng
NO This journal is © The Royal Society of Chemistry 2019This work was financially supported by FEDER funds through the COMPETE 2020 Programme and National Funds through FCT - Portuguese Foundation for Science and Technology under projects UID/CTM/50025/2019 and POCI-01-0145-FEDER-028755. Kiel authors thank the Deutsche Forschungsgemeinscha. (DFG) for financial support under the scheme SFB 677 (C14). EN and BM thank Spanish MINECO for funding via the project MAT 2015-65274-R-FEDER.
NO Unión Europea. H2020
NO Ministerio de Economía y Competitividad (MINECO)
NO Deutsche Forschungsgemeinscha (DFG)
DS Docta Complutense
RD 8 abr 2025