LASER INDUCED SYNTHESIS OF POLYMERIC NANOCOMPOSITE MATERIALS AND DEVELOPMENT OF MICRO-PATTERNED HYBRID LIGHT EMITTING DIODES (LED) & TRANSISTORS (LET)
The project has developed a prototype of light emitting device using as emitted materials a semiconductor QDs in a polymeric matrix activated by means of direct laser patterning.
The main objective of this project was the implementation of an advanced novel method (direct laser micro-patterning - DLP), for the development of a LED and LET matrices (pixels) based on QDs formed in situ in a polymeric matrix (QD-LED/LETs). The project achieved three main goals: a) the development of suitable materials. The material synthesis comprised both QD precursor development and polymer matrix development. The two components was mixed and thermally treated in order to obtain the desired nanocomposite; b) the formation of a polymer nanocomposite through laser irradiation. The direct laser patterning (DLP) technology on polymeric matrices was developed through setting up of different laser sources, tested in order to optimise the synthesis of the nanocomposites. c)fabrication of a QD-LED/LET based on a) and b). The main goal of the project was the realisation of a light emitting device formed by QDs pixelated structures and the use of DLP as patterning instead of the current methods (photolithography).
The LCA and Ecodesign laboratory has carried out an LCA analysis study on QDs-LED (Quantum Dots Light Emitted Diodes) using a direct laser micro-patterning to produce the light emission of QDs, that are in polymeric matrix as precursor. The QDs-LED are produced using organic polymers. The aims of the LCA study were the following: -to identify the potential environmental impacts coming from the innovative system QD-LED as well as to allow the comparison of the environmental performance of different patterning technologies -to support a 'low impact' design of the systems. The study compares two systems: 1. QDsLEd by patterning that incudes QDsLEd without patterning + patterning by UV Photolitography 2. QDsLEd by laser that includes QDsLEd without patterning + patterning by EKSPLA Laser The results coming from the LCA study of QDsLED production by photolithography shows the same potential environmental impacts as QDsLED production by Laser for all impact categories. In conclusion, the new technology of laser patterning does not show any environmental benefit if compared to the photolithography. The impacts are the same for all impacts categories considered. Therefore, the use of this new technology requires that other important parameters are checked such as best technology performance, time consumed in the production and costs of the technology. Moreover the study has identified that the main environmental impacts stemming from polymer production are due to the energy consumption of polymer and monomers, to the hexane production and to palladium production. These impacts are related to the laboratory scale production. Indeed this inefficiency could be overcome during the scale up of production where the yield of production, the use of solvents and the energy consumption would be optimized.
The study highlighted the hotspots in the development of this new technology. This information will permit to improve the production of this new device to development environmental sustainable product.