A145 Mater. Res. Soc. Symp. Proc. Vol. 1534 © 2013 Materials Research Society DOI: 1 557/op 013 0.1 l.2 . Photoinduced Photoluminescence Enhancement in CdSe Quantum Dot – Polyvinyl Alcohol Composites L. Borkovska 1 , N. Korsunska 1 , T. Stara 1 , V. Bondarenko 1 , O. Gudymenko 1 , O. Stroyuk 2 , O. Raevska 2 and T. Kryshtab 3 1 V. Lashkaryov Institute of Semiconductor Physics, NASU, pr. Nauky 41, 03028 Kyiv, Ukraine 2 L. Pysarzhevsky Institute of Physical Chemistry, NASU, pr. Nauky 31, 03028 Kyiv, Ukraine 3 Instituto Politécnico Nacional – ESFM, Av. IPN, Ed.9 U.P.A.L.M., 07738 Mexico D.F., Mexico ABSTRACT The effect of thermal annealing at 100 o C under irradiation by LED’s light of 409 nm on the photoluminescence (PL) of polymer films of polyvinyl alcohol (PVA) and PVA films with embedded CdSe quantum dots (QDs) was investigated. X-ray diffraction study revealed that annealing increases a degree of crystallinity of the PVA matrix in the both films studied. In the PL spectra of the annealed QD-PVA composite, both an increase (up to thirteen- folds at room temperature) of the QD-related PL band and a small spectral shift toward the red spectrum region were found. The PL intensity at low temperatures and the activation energy of the PL thermal quenching also increased. In the PL spectra of pure PVA, a small decrease in the PL intensity and a red shift of the PL band were observed. The color of the composite film changed from yellow to slightly reddish with no changes in the PVA film transparency. The effect of PL enhancement in CdSe QD-PVA composite is ascribed to the improvement of QD surface defect passivation by the functional groups or the polymer chain fragments of PVA matrix caused by photochemical transformations in the polymer. INTRODUCTION An interest to polymers with embedded metal or semiconductors nanoparticles in device application is motivated by novel and distinctive properties of such composites resulted from the combination of intrinsic characteristics of polymers and the unique properties of nanoparticles [1]. Polyvinyl alcohol (PVA) is a well accepted human- and environmental-friendly polymer that is used in various pharmaceutical, medical, cosmetic, food and agricultural products [2]. It is also characterized by good thermo-stability, chemical resistance, and film forming ability [3]. Thus, PVA is considered as a good host material for metal and semiconductor nanoparticles. PVA- protected Ag [4], Pt [5] and Au [6] nanoparticles as well as ZnO [7], CdS[8] and CdSe [9, 10] quantum dots (QDs) have been reported. PVA is known to undergo photochemical transformations under γ-quanta or UV-light irradiation that change its mechanical, optical and luminescent characteristics [3]. However, the photoinduced evolution of the properties of PVA- based nanocomposites is less studied [8]. 312