Print Email Facebook Twitter Direct measurement of the triplet exciton diffusion length in organic semiconductors Title Direct measurement of the triplet exciton diffusion length in organic semiconductors Author Mikhnenko, O.V. Ruiter, R. Blom, P.W.M. Loi, M.A. Publication year 2012 Abstract We present a new method to measure the triplet exciton diffusion length in organic semiconductors. N,N′-di-[(1-naphthyl)-N,N′-diphenyl]-1,1′-biphenyl)-4,4′-diamine (NPD) has been used as a model system. Triplet excitons are injected into a thin film of NPD by a phosphorescent thin film, which is optically excited and forms a sharp interface with the NPD layer. The penetration profile of the triplet excitons density is recorded by measuring the emission intensity of another phosphorescent material (detector), which is doped into the NPD film at variable distances from the injecting interface. From the obtained triplet penetration profile we extracted a triplet exciton diffusion length of 87±2.7nm. For excitation power densities >1mW/mm2 triplet-triplet annihilation processes can significantly limit the triplet penetration depth into organic semiconductor. The proposed sample structure can be further used to study excitonic spin degree of freedom. © 2012 American Physical Society. Subject Mechatronics, Mechanics & MaterialsHOL - HolstTS - Technical SciencesHigh Tech Systems & MaterialsElectronicsIndustrial InnovationDirect measurementEmission intensityExcitation power densityModel systemPenetration profilesPhosphorescent materialSample structureSharp interfaceSpin degreesTriplet excitonsTriplet-triplet annihilationDiffusionInterfaces (materials)NaphthalenePhosphorescenceProduct developmentSemiconducting organic compoundsThin filmsExcitons To reference this document use: http://resolver.tudelft.nl/uuid:97a13ce1-eb77-4299-9d5e-3e2ea6a3ab1d TNO identifier 461328 ISSN 0031-9007 Source Physical Review Letters, 108 (13) Article number 137401 Document type article Files To receive the publication files, please send an e-mail request to TNO Library.