The Performance Shift due to Light Irradiation on the Electrode of an All-Solution-Processed Semitransparent Polymer Solar Cell

The performance shift of an all-solution-processed semitransparent polymer solar cell is investigated under light irradiation. All the devices are fabricated using polyethylene glycol (PEG)-doped poly(3,4-ethylenedioxythiophene):poly(styrene-sulfonate) (PEDOT:PSS) without light treatment (different light intensity and processing time) as transparent electrode. The performance increase is observed with light irradiation for freshly fabricated devices. For the long stored devices in the glove box, their initial performance can be partially restored after light irradiation. The main reason for this performance shift is due to the increase in the conductivity of the transparent electrode PEDOT:PSS. Due to the conformation change of PEDOT chains after light irradiation, the conductivity increase and possible reduction of the contact resistance are beneficial for performance improvement.