High indoor performance of flexible organic photovoltaics using polymer electrodes

Indoor organic photovoltaics (OPVs) have gained tremendous attention due to their unique optoelectronic properties under dim and spectrally-limited indoor light conditions. Moreover, their excellent flexible features make them more suitable for powering various indoor electronic devices than other photovoltaic systems. In this article, we demonstrate the indoor photovoltaic performance of poly(3-hexylthiophene):indene-C₆₀ bisadduct-based flexible OPVs with polymeric electrodes in comparison with reference OPVs with indium tin oxide (ITO) electrodes. For the flexible OPVs, poly (3, 4-ethylenedioxythiophene): poly (styrene-sulfonic acid)-based polymeric electrodes were demonstrated on a polyethylene naphthalate substrate with a polyvinyl alcohol buffer layer. The OPV with the polymeric electrode produced an average power conversion efficiency (PCE) of 11.1 ± 0.1%, whereas the reference device with the ITO electrode exhibited a PCE of 8.8 ± 0.1% under a 500-lx-light emitting diode condition. The flexible OPVs also exhibited superior flexibility over reference OPVs by retaining their PCE up to ~ 85% even after 500 bending cycles in air, whereas the reference OPVs declined to ~ 80% of their PCE under the same bending conditions.