Organic energy-harvesting devices achieving power conversion efficiencies over 20% under ambient indoor lighting

The ability of solution-processed organic photovoltaics (OPVs) based on new small-molecule semiconductors, 1DTP-ID and 2DTP-ID, for indoor dim-light energy harvesting is reported. Indoor OPVs with the best performance achieve high power conversion efficiencies, over 20%, under white LED illumination at 200–2000 lx. Flexible OPV modules using 1DTP-ID with an active area of ∼10 cm2 are capable of delivering a maximum power output of ∼0.1 mW and an open-circuit voltage of ∼4 V even at 200 lx, ideal for use as dispersive self-sustainable power sources for the Internet of Things.