Investigation of glyme additives to metalorganic ink systems

Printing of metal oxides at low temperatures is highly challenging, and highly reactive metalorganic inks have been investigated to achieve the target material using process conditions below 150 °C. Unfortunately, their reactivity prohibits facile handling along with making treatment with water to form sol–gels impossible to control and so glyme additives have been investigated to reduce sensitivity without compromising printed material conversion to metal oxide. In this paper, we report addition of a range of glymes to ink formulations and an assessment of the stability enhancement achieved through a range of exposure trials. A clear improvement in air/moisture stability is demonstrated in all cases. Evaluation of the thermal requirements to remove an organic material with and without the additives has been performed with diglyme, proving to be the optimum stabilisation agent leading to minimal change in the process conditions required. Further studies with additional metal doping is planned to enable transparent conducting coatings to be fabricated at low temperatures on flexible plastic substrates.