Flexible image sensor array with bulk heterojunction organic photodiode

Thick organic bulk heterojunction photodiodes with low dark current < 1 nA/cm(2) and efficient charge collection are reported. An electric field > 1 V/mu m is sufficient to achieve > 75% charge collection in films of poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylene-vinylene] and [6,6]-phenyl-C61-butyric acid methyl ester blends up to 4 mu m thick, and the rate of photocurrent decay is reduced at saturation fields. The integration of a 4 mu m thick sensor layer onto a flexible amorphous silicon thin-film transistor backplane gave an image sensor array with 35% external quantum efficiency and noise equivalent power of 30 pW/cm(2) at reverse bias voltage of -4 V. (c) 2008 American Institute of Physics.