TY - JOUR
T1 - Reversible Charge-Carrier Trapping Slows Förster Energy Transfer in CdSe/CdS Quantum-Dot Solids
AU - Montanarella, Federico
AU - Biondi, Margherita
AU - Hinterding, Stijn O.M.
AU - Vanmaekelbergh, Daniel
AU - Rabouw, Freddy T.
PY - 2018/9/12
Y1 - 2018/9/12
N2 - The dynamics of photoluminescence (PL) from nanocrystal quantum dots (QDs) is significantly affected by reversible trapping of photo-excited charge carriers. This process occurs after up to 50% of the absorption events, depending on the type of QD considered, and can extend the time between photo-excitation and relaxation of the QD by orders of magnitude. Although many opto-electronic applications require QDs assembled into a QD solid, until now reversible trapping has been studied only in (ensembles of) spatially separated QDs. Here, we study the influence of reversible trapping on the excited-state dynamics of CdSe/CdS core/shell QDs when they are assembled into close-packed "supraparticles". Time- and spectrally resolved PL measurements reveal competition between spontaneous emission, reversible charge carrier trapping, and Förster resonance energy transfer between the QDs. While Förster transfer causes the PL to redshift over the first 20-50 ns after excitation, reversible trapping stops and even reve...
AB - The dynamics of photoluminescence (PL) from nanocrystal quantum dots (QDs) is significantly affected by reversible trapping of photo-excited charge carriers. This process occurs after up to 50% of the absorption events, depending on the type of QD considered, and can extend the time between photo-excitation and relaxation of the QD by orders of magnitude. Although many opto-electronic applications require QDs assembled into a QD solid, until now reversible trapping has been studied only in (ensembles of) spatially separated QDs. Here, we study the influence of reversible trapping on the excited-state dynamics of CdSe/CdS core/shell QDs when they are assembled into close-packed "supraparticles". Time- and spectrally resolved PL measurements reveal competition between spontaneous emission, reversible charge carrier trapping, and Förster resonance energy transfer between the QDs. While Förster transfer causes the PL to redshift over the first 20-50 ns after excitation, reversible trapping stops and even reve...
KW - Förster energy transfer
KW - Nanocrystal
KW - charge-carrier trapping
KW - colloidal quantum dot
KW - delayed emission
U2 - 10.1021/acs.nanolett.8b02538
DO - 10.1021/acs.nanolett.8b02538
M3 - Article
C2 - 30095918
SN - 1530-6984
VL - 18
SP - 5867
EP - 5874
JO - Nano Letters
JF - Nano Letters
IS - 9
ER -