Semiconductor quantum dots (QDs) have been the subject of much interest for both fundamental research and technical applications in recent years, due mainly to their strong size dependent 3,0 properties and chemical processibility. Here, we 2,5 describe the synthesis and the characterization of colloidal CdSe nanoc1ystals within the size range of 2.57 - 3.4 nm, synthesized at temperatures ranging (85-150 °C) [1]. In this approach, cadmium acetate dehydrate, and 0,5 selenium powder are used as Cd and Se 0,0 precursors, respectively, oleic acid as a ligand, CdSe nanoc1ysals display striking absorption Fig.1.Absorbance spectra of CdSeQD grown and emission features arising from their at 15O°C, 12O°C, 85 °C. "aitificial atom" character. The absorbance spectra of synthesized quantum dots (QD) with sizes 2.57 nm, 2.9nm and 3.4nm -a-1so"c and size dispersion about 5.3% is shown in -o-120 °c Fig.I. The photoluminescence spectra(Aexc=337.1 nm) of oleic acid capped QDs is shown in Fig.2, where two different emission bands are obse1ved. The maximum of luminescence is red shifted with the reaction temperature increased. The cmve with maximum at 565 run has a lmninescence tail at longer wavelengths. This is a sign of Stokes shift as well a sign for a state Fig.2.Luminescence spectra of CdSeQD splitting into one optically allowed (strongly grown at 15O0c, 12O0c, 85 oc_ absorbing) state and one optically forbidden (weakly emitting) state, from the lowest transition (lS312, lse) [3]. The more defined shaip peak at shorter wavelength is due to luminescence from the QD band edge exciton. The smface band is red-shifted from the core band. This surface photoluminescence is thought to arise from a distribution of nonpassivated selenium defects on the nanocrystal surface [4]. During the whole reaction process, the growth pf the pa1ticles was cleai·ly evidenced by the shift of both abso1ption and emission spectra to longer wavelengths as a consequence of quantum confinement effect. With the reaction temperature increased, the growth rate of the CdSe nanocrystlas increase.