  We report on a temporal evolution of photoluminescence (PL) spectroscopy of
CuInS$_{2}$/ZnS colloidal quantum dots (QDs) by drop-casting on SiO$_{2}$/Si
substrates and high quality factor microdisks (MDs) under different atmospheric
conditions. Fast PL decay, peak blueshift and linewidth broadening due to
photooxidation have been observed at low excitation power. With further
increasing of the excitation power, the PL peak position shows a redshift and
linewidth becomes narrow, which is ascribed to the enhanced F$\ddot{o}$rster
resonant energy transfer between different QDs by photoinduced agglomeration.
The oxygen plays an important role in optically induced PL decay which is
verified by reduced photobleaching effect in vacuum. When the QDs drop-casted
on MDs, photooxidation and photobleaching are accelerated because the
excitation efficiency is greatly enhanced with coupling the pumping laser with
the cavity modes. However, when the emitted photons couple with cavity modes, a
PL enhancement by more than 20 times is achieved because of the increased
extraction efficiency and Purcell effects of MDs at room temperature (RT), and
35 times at 20 K. The photobleaching can be avoided with a small excitation
power but with a strong PL intensity by taking advantages of high quality
factor cavities. The high efficient PL emission without photodegradation is
very promising for using CuInS$_{2}$ QDs as high efficient photon emitters at
RT, where the photodegradation has always been limiting the practical
applications of colloidal quantum dots.
