Fabrication and performance studies of TiOz and Porphyrin Heterojunction based organic photodetector

摘要

Organic photodetector of TiOz/Porphyrin has been fabricated and its performance has been tested in dark and underudvaiious illumination of light intensityfrom 20 to 100 mWcm-'. Foursamples of porphyrin films have been used in the device,udnamely 1, 3, 5 and 7 times spin coating. TiOz films were deposited onto ITO covered glass substrate by controlledudhydrolysis technique assisted with spin coating technique. Then porphyrin film was deposited on TiOz using spin coatingudtechnique. The films of TiOz/porphyrin has absorbance maximum at 660 nm, which is in the red region. An aluminiumudelectrode was prepared on top of porphyrin films by electron beam evaporation technique. The device shows rectificationudbehaviour in the dark and shows photosensitization effect under illumination of visible lights. The device with 3 times spinudcoating of porphyrin shows the highest J"" of 1.02 pAcm'2 and Vo" of 520 mV.ud(Received November 2, 2009; accepted November 12,2009)udKeyv,ords : Photodetector, Photosensitizing, Porphyrin, Ti02