Layer-selective laser ablation patterning

A method of fabricating an organic electronic device on a flexible substrate, said organic electronic device having a structure including an inorganic metal upper conductive layer and an underlying layer immediately beneath said upper conducting layer, the method comprising patterning said inorganic metal upper conductive layer of said structure by:

• laser ablating said inorganic metal upper conductive layer using a pulsed laser to remove a region of upper conductive layer from said underlying layer for said patterning, wherein said upper conductive layer has a first ablation threshold and a transmittance at a wavelength of said pulsed light;
• wherein said laser ablating uses a single pulse of said laser to substantially completely remove said region of said inorganic metal upper conductive layer to expose said underlying layer beneath;
• wherein said underlying layer has a second ablation threshold and wherein the second ablation threshold is greater than a product of the first ablation threshold and the transmittance and wherein the fluence of said laser pulse is greater than said second ablation threshold;
• and
• wherein said underlying layer is substantially undamaged by said ablating wherein said underlying layer comprises a layer formed of an organic material;
• and wherein said inorganic metal upper conductive layer has an optical density greater than 1.