A planar organic near infrared light detector based on bulk heterojunction of a heteroquaterphenoquinone and poly[2-methoxy-5-,2 '-ethyl-hexyloxy)-1, 4-phenylene vinylene

Planar organic detectors for the near infrared region of the light spectrum have been realized, processing from solution the quinoid molecule 5,5'-bis(3,5-di-tert-butyl-4-oxo-2,5-cyclohexadiene-1-ylidene )-5,5'-dihydro-2,2'-bithiophene (QBT), which shows a peculiar absorption at 680 nm. Sensitization of the active material was obtained by creating a bulk donor-acceptor interface with poly[2-methoxy-5-(2'-ethyl-hexyloxy)-1,4-phenylene vinylene], which acts as hole acceptor. Photoexcitation and relaxation dynamics in pristine materials and bulk heterojunction have been investigated by means of pump-probe measurements, revealing charge transfer from QBT to polymer and efficient energy transfer the other way round. (C) 2008 American Institute of Physics. [DOI: 10.1063/1.3033376]