聚合物-CdSe/ZnS量子点复合薄膜的制备及其荧光性能研究

Preparation and Characterization of Polymer-CdSe/ZnS QDs Composite Thin Film

以两性齐聚物(聚马来酸十六醇酯,PMAH)为修饰剂,利用相转移的方法将油溶性的CdSe/ZnS量子点转移至水中,制备出高量子产率、高稳定性的水溶性CdSe/ZnS荧光量子点.随后将PMAH修饰的水溶性量子点分散到聚丙烯酸(PAA)乳液中,采用旋转涂膜的方法制备了透明的聚合物-CdSe/ZnS量子点复合薄膜,在紫外灯的照射下薄膜发出明亮的红色光.利用XPS对复合薄膜的表面结构进行了表征.随后对膜的光致发光性能和薄膜在黑暗的环境中对紫外光的耐受性进行了系统的研究,发现复合薄膜的荧光强度随着薄膜厚度和薄膜中纳米晶浓度的增加而线性增强,薄膜在紫外光照射800h后仍然保持了很高的荧光强度,量子产率仅仅损失了5%。

High quality water-soluble semiconductor CdSe/ZnS quantum dots（QDs） were prepared by a phase transfer method,in which amphiphilic oligomers（polymaleic acid n-hexadecanol alcohol ester,PMAH） was used as surface coating agents.The as-prepared aqueous QDs were high fluorescent and extremely stable.To form the composite emulsion,different concentration of water-soluble CdSe/ZnS QDs was dispersed in PAA emulsion.The polymer-CdSe/ZnS QDs composite thin film was then fabricated using the composite emulsion with a spin-coating method.The obtained CdSe/ZnS QDs composite thin film was transparent under sun light and had bright red light under the irradiation of UV light.The composite thin film was also characterized with X-ray Photoelectron Spectroscopy.The photoluminescence（PL） property and tolerance to UV light of the thin film were also characterized in dark circumstances.The PL intensity of the film showed increment with the increase of layer number and the concentration of CdSe/ZnS QDs within each film.Furthermore,the composite film retained its high quantum yield（QY） with only 5% QY lost after UV irradiation for 800 h.