An important step during the development of organic electronic devices is the purification of the starting materials that are used to fabricate thin films. In chemistry, purity of a material is required to check the product of a reaction by elemental analysis. When materials such as organic semiconductors are tested in optoelectronic devices, their electronic properties are sensitive to small densities of impurities. Therefore, extensive purification is required to separate intrinsic from extrinsic effects. Experience has shown that the lifetime and yield of devices fabricated from low purity materials are poor.
In our laboratory we purify organic semiconductors that can be processed from the vapor phase using thermal gradient zone sublimation.
Materials processed from solution are purified by multiple recrystallization processes.