Semiconductor film comprising discrete domains of an organic semiconductor and a method of its fabrication

Abstract

According to a first aspect, the present invention provides a method for forming a semiconductor film comprising a first step of providing a solution comprising a first organic semiconductor and a second organic semiconductor on a surface of a substrate. The solution is then dried to form the semiconductor film so that it comprises discrete domains of the first organic semiconductor in a matrix of the second organic semiconductor which electrically connects adjacent domains of the first organic semiconductor. The first and second semiconductors are of the same conductivity type. The mobility of charge carriers in the domains of the first organic semiconductor is higher than the mobility of charge carriers in the matrix of the second organic semiconductor. In alternative aspects, the present invention provides methods forming similar semiconductor film products but in which a solution of the first organic semiconductor is deposited separately from the second organic semiconductor and dried to form discrete domains. The present invention also provides a semiconductor film such as produced by the above methods in which both the first and second organic semiconductors are thiophenes.