CHEM01200604009 Sreejith Kaniyankandy - Homi Bhabha ...

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Figure 3: Panel A: Normalized kinetic traces photoexcited CdTe for different particle sizes
at 610 nm (1S exciton position). Panel B: Plot of cooling time (growth kinetics at 1S exciton)
vs particle size showing non-linear increment.
To confirm the involvement of Auger mediated cooling processes we have carried
quenching studies where the quenchers can selectively accept electrons or holes and then find
out the effect of cooling dynamics of the lowest excitonic (1S 3/2 -1S e ) state. The quenchers
can decouple electrons or holes selectively which eventually hinders the energy transfer from
the electron to the hole. In the present studies we have used benzoquinone (BQ) as electron
quencher and n-butyl amine (BA) as hole quencher. Figure 4 show the kinetic trace at 1S
exciton position (monitored at 610 nm) of CdTe QD in absence of any quencher (Figure
4.4a), in presence of electron quencher (BQ) (Figure 4.4b) and in presence of hole quencher
(BA) (Figure 4.4c). In presence of BQ, it is expected that hot electron will be quenched. In