For all sensors,the open circuit voltage (Voc) was within the range of 0.1–0.2 V, however, for an individual sensor, the Voc did not shift as illuminance increased. Previous researchers [20] observed a logarithmic increase in the Voc in PFB:F8BTbilayer devices from increasing Argon-ion laser intensity
(based on 458 nm line), but for those measurements, the
Voc saturated at radiometric intensities above 0.7 mW/
cm2, which is significantly lower than the testing conditions
used in the experiments described here.