Printed and laminated LED based on ZnO nanowires

Important results from the project

Aim of the project was to develop a demonstrator that provides light over 10´s of square centimeters by using standard printing techniques combined with lamination technology for the manufacturing of white LEDs based on nanowires of ZnO. The project demonstrated emission from parts of the component, but not uniformly from the whole surface. A conductive adhesive was developed. However, without getting enough good long-term adhesion between the joined surfaces which caused delamination after some time. No IP related to the project was filed.

Expected long term effects

The expected outcome of the project was to produce a conductive adhesive based on nanoparticles of ZnO in combination with a conductive nanomaterial for lamination of LED structures and to demonstrate white light over tens of square centimeters. A binderwas developed with good conductive properties, but with limitation in the adhesion over time. Different printing techniques was tested, but we didn´t managed to trim the process good enough, ie, layer thicknesses etc which gave rise to problems with the adhesion over time causing delamination over time.

Approach and implementation

The project was performed together with Acreo and their unit for printed electronics (PEA). Initially alternative conductive adhesives were studied and the most suitable ones were selected for testing. In-house produced ZnO nanoparticles and purchased tetrapod particles were evaluated to be used in the binder. Printing techniques were studied before practical evaluation. Regular project meetings were held to distribute work and to manage the project. Purchases of materials took longer than expected. Earlier identification of the material could shortened the project duration.