NOVELTY - Fabrication of solid state structures involves masking a film; etching substrate (1); removing the mask from substrate; cleaning the substrate; depositing a hole injection layer (3) (HIL) on the substrate; depositing light-emitting polymer layer (4) on the HIL; masking light-emitting polymer layer; and depositing a cathode layer (5) on the masked light-emitting polymer layer in an electroless solution; and encapsulation of solid state structure formed by deposition of cathode layer.    USE - For fabrication of solid state structures (claimed), used in electronic devices e.g. organic light emitting device, polymer light emitting device, polymer solar cells and thin-film transistor.    ADVANTAGE - The method needs less time for fabrication of device compared to vacuum deposition; no time needed for loading and pumping of a vacuum chamber; less materials are consumed; most of the material during thermal evaporation is deposited in the rest of the chamber. The electroless plated films are more than ten times thinner than the screen printed silver paste films, hence ten times less material will be used. The electroless plated films do not necessarily need post-deposition annealing, in contrast to the use of silver paste. Less capital equipment is needed with less maintenance cost; a typical vacuum system is expensive and requires periodic maintenance. The sensitization step offers a natural way for patterning of the metal electrodes. The metal is formed during the deposition process. This is conceptually different from the deposition of a paste where the metal particles are formed in advance and the integrity of the film is maintained by the weak interaction between the particles. The lack of electrodes (as in electroplating and plasma deposition) and of spatially constrained source of material allows easy scaling of the deposition process and uniform deposition on non-planar surfaces.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for depositing a cathode layer on a solid state structure involving masking an indium tin oxide (ITO) glass substrate that includes a hole injection layer on the substrate and a light-emitting polymer on the hole injection layer, where the mask is on the light-emitting polymer; sensitizing the substrate with an ionic catalyst; annealing the substrate; applying a cathode solution to the substrate to deposit a cathode layer on the substrate; and annealing the cathode layer on the substrate.    DESCRIPTION OF DRAWING(S) - The figure shows a schematic view of polymer light emitting device.    Glass substrate (1)    Anode (2)    Hole injection layer (3)    Light-emitting polymer layer (4)    Cathode layer (5)