  Surface traps and associated emission in quantum dots (QDs) sought a lot of
research attention because of the fundamental interests apart from their
influence on the emission characteristics. In ref [Acc. Chem. Res. Vol 43 (2)
pp 190, 2010] the hole traps (h-traps) are depicted close to the conduction
band (CB) for CdSe QDs while discussing the emission mechanism. However,
notably electron traps (e-traps) are close to CB and h-traps are supposedly
close to the valance band, especially in anion rich CdSe QDs. Although such
emission (so called deep-trap) is a well known phenomenon, the energetic
locations of these traps and the associated discrepancy require further
attention. Hence the distinction between e, h-traps and their energetic
location within the band gap is addressed in a general context, which is
essentially a revisit to the surface states. Finally this general description
is put to the context of surface states of CdSe QDs.
