The self-assembled CdSe quantum dots (QDs) were fabricated on GaAs(110) substrate by in molecular-beam epitaxy (MBE) the Stranski-Krastanow (S-K) growth mode.By using temperature dependence PL spectra of CdSe QDs with 3ML(monolayer) and 10ML deposition thickness.We found the CdSe QW has strong emission only at low temperature and totally quenched at room temperature.The CdSe QDs keep the emission to room temperature due to the effect of quantum size confinement with three dimensions.As for the 3ML sample

it has six PL peaks from ZnSe barrier;CdSe QDs;1ML;2ML;1LO and 2LO assisted 2ML CdSe QW wetting layers at 20 K

respectively.From 20 to 200 K

the PL intensity of 1ML CdSe QW monotonly decrease and the peak energy red shifted heavily with the temperature raising.And we only observe two peaks for Cdso QDs and 2LO assisted 2ML at 300 K.The intensity decrease due to the exciton-phonon coupling enhanced with the increasing temperature

while the peak largly red shift was attributeed to the reduced band gap and the exciton-phonon coupling with increasing temperature.As for the 10ML sample

the PL intensity of CdSe QDs decrease quickly from 50 to 250 K.The thermal active energy for CdSe QDs is calculated.The energy of 34 meV is less than the differences between CdSe QW emission and CdSe QDs centre peak energy

so we attribute the CdSe QDs PL was quenched from the localized states.The PL intensity suddenly enhance from 250 to 300 K

the process is caused by the localized states released at higher temperature.The excitation power dependence of PL intensity spectra which have the linear relation verifies that the CdSe QDs emission is the free-exciton radiative recombination.In the mean time

the state filling effect in CdSe QDs is also observed by employing excitation power dependence of the PL peaks at 20 K.In comparison the PL spectra of 3ML with 10ML samples at 20 K

it is found that the ratio of CdSe QDs and CdSe QW PL intensities is com-pleteky different

the later(10ML sample) has higher intensity for CdSe QDs.As a result

the different CdSe active layers affect the strain relaxation and form the different size and distribution of CdSe QDs

the 3ML is the critical thickness for CdSe layers grown on the GaAs(110) substrate

while the 10ML is larger than that. So the different strain relaxation results in different CdSe QDs emission between 3ML and 10ML samples.