Nanoscale Effects on the Optical Properties of Polymeric Nanofiber-Quantum Dot Composites
J.L. Davis, T.A. Walker, H.J. Walls, L. Han, K. Mills, K. Guzan
RTI International, US
Keywords: nanofiber, quantum dot, optical properties, light scattering, quantum efficiency
Abstract:Photoluminescent nanofibers can be formed by combining electrospun polymeric nanofibers and quantum dots. The physical properties of PLNs are dependent upon many different nanoscale parameters associated with the nanofiber, the quantum dots, and their interactions. By understanding and manipulating these properties, the performance of the resulting optical structure can be tailored for desired end-use applications. For example, the transmittance and reflectance of nanofiber substrates is controlled by factors such as fiber diameter, fiber surface nanoscale morphology, and index of refraction. Hence a given polymeric nanofiber can be switched from possessing high optical transparency in the visible spectrum to being an excellent diffuse reflector simply by altering its nanoscale properties. Likewise, the quantum efficiency of quantum dots in the PLN structure depends upon multiple parameters including quantum dot chemistry, the method of forming the PLN nanocomposites, and preventing agglomeration of the quantum dot particles. With the proper control of these parameters, quantum efficiencies in excess of 0.7 can readily be obtained for PLNs. Methods of optimizing the performance of PLNs through nanoscale manipulation are discussed along with guidelines for tailoring the performance of nanofibers and quantum dots for application specific requirements.