Controlling the carrier concentration in semiconductor quantum dots is an important next step to tailor the quantum dot properties for electronic applications. This research is exploring the possibility to incorporate gallium, indium and tin dopants into CdSe quantum dots. The CdSe quantum dots are grown at a relatively low temperature using a single precursor. In situ absorbance and fluorescence spectroscopy of the quantum dot growth solution indicates that CdSe QDs exhibit 'heterogeneous' growth. The average size and size distribution of the QDs is primarily controlled not by the usual focusing�defocusing (Ostwald ripening) of particles, but rather by the formation of 'magic' sized clusters. In these studies, we explore the effect of indium, tin and gallium doping on the growth kinetics of the particles, which affects the size, the size distribution, the kinetics as well as the emission quantum yield (see below) in many significant ways. The doped quantum dots show new interesting properties. The tin, indium and gallium significantly enhances the temperature dependant photoluminescence of CdSe QDs. Conductivity measurements of the doped dots also indicate enhancement over undoped counterparts. Transient absorption and temperature dependant PL experiments show significant backfilling of states in the doped quantum dots.

Doping semiconductor quantum dots

239th National Meeting (2010)

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