Microstructured UV-sensitive luminescent sol–gel layers

Abstract Carboxylic acid complexes of lanthanide ions may show an excellent sensitivity to UV radiation and often a luminescence quantum yield near unity. By incorporating them into an inert matrix such as a sol–gel layer, it is possible to prevent degradation of the complexes under atmospheric conditions or by UV irradiation. This work focuses on the lateral structuring of thin sol–gel layers which have been doped with two different luminescent complexes, namely terbium picolinate and europium picolinate. It is demonstrated that structuring of the doped layers with standard photolithographic processes is possible, without harming the luminescent properties of the incorporated complexes. Best results are achieved in an image reversal process, while the lift-off approach with a thick layer of photoresist leads to inhomogenities in the layer. Smallest features of 40 μm were reproduced with excellent edge quality.