Photoluminescence and absorption studies of CdSe quantum dots in polymethylmethacrylate
(PMMA) were carried out in the temperature range 14 - 310 K. We found an anomalously discontinuous
variation of the photoluminescence intensity and the peak position around 50 K. Two different kinds of
states, whose populations are temperature-dependent, are proposed as the origins for the emissions at lower
and higher temperatures. The absorption exhibited a temperature-dependent behavior similar to that of the
photoluminescence.
