Abstract
We report a systematic study of the optoelectronic processes occurring in composites made of near-infrared (IR) emitting nanocrystals and conjugated polymers. We focus on PbSe and InAsZnSe blended with polyphenylenevinylene-type polymers. We find that the process responsible for quenching the visible luminescence of the polymer by the nanocrystal varies depending on the nanocrystal composite. Moreover, the high (66%) energy-transfer efficiency from the polymer to the PbSe nanocrystal does result in significant emission at the near IR. Our measurements suggest that the host may be doping the PbSe nanocrystal, thus making the nonradiative Auger process favorable. For InAs we find the energy levels well aligned inside the polymer band gap, making it an efficient charge trap which acts as a luminescence center. Through two-dimensional numerical modeling of the charge transport in such composite films we highlight the importance of morphology (nanocrystal distribution) control.
Original language | English |
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Article number | 074310 |
Journal | Journal of Applied Physics |
Volume | 98 |
Issue number | 7 |
DOIs | |
State | Published - 1 Oct 2005 |
Externally published | Yes |
Bibliographical note
Funding Information:We acknowledge support by the Israel Ministry of Science and Technology, partial support by the EU through Contract No. G5RD-CT-2001-00577 OPAMD, partial support from the Deutsche-Israel Program (DIP), and partial support by the Niedersachsen foundation. We thank Avecia/Covion for the supply of the yellow PPV. Two of the authors (O.S. and A.S.) express deep gratitude to the Center of Absorption in Science, Ministry of Absorption, Israel.