Patent ID: 7468287
Filing Date: 2008-12-23
Classification: H01L,Y02E

Abstract:
1. A method of forming a heterojunction of contiguous layers of first and second organic semiconducting polymers comprising the steps of: (i) forming a layer of the first organic semiconducting polymer on a substrate, (ii) depositing a solution of a film-forming material on the layer of the first organic semiconducting polymer, the first organic semiconducting polymer being insoluble in the solution, (iii) drying the deposited solution to form a temporary film having a thickness of less than 20 nm formed from the film-forming material, (iv) depositing a solution of the second organic semiconducting polymer dissolved in an organic solvent (A) on the temporary film, and (v) drying the deposited solution, the solubility of the material forming the temporary film in the organic solvent (A) and the thickness of the temporary film being such that the organic solvent (A) permeates through the thickness of the temporary film during the duration of the drying step (v) causing the temporary film to break down but without substantially disturbing the layer of the first organic semiconducting polymer so that the layer of the second organic semiconducting polymer is formed contiguously on the layer of the first organic semiconducting polymer.