Polarized Near-infraered Light Emitting Devices Fabricated With Low-band-gap Polymer Oriented Films

摘要

We fabricated polarized near-infrared (NIR) emitting devices using with the oriented films of a low-band-gap-polymer PTB7 (poly{4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b']tithiophene-2,6-diyl-alt-3-fluoro-2- [(2-ethylhexyl)carbonyl]thieno[3,4-b]thiophene-4,6-diyl}) as the emitting layer. The oriented PTB7 films were fabricated on substrates with transparent electrodes by friction transfer method. Overlaying a visible-light emitting polymer, F8BT (poly(9,9-dioctylfluorene-alt-benzothiadiazole)) on it, followed by vacuum-depositing metal cathodes, made efficient light-emitting devices. The devices emitted NIR lights trough energy transfer from F8BT to PTB7. Moreover, the emitted light was linear-polarized, as the PTB7 main chains were uniaxially oriented in the substrate plane.