Improving the photostability of printed organic photovoltaics through luminescent solar concentrators

Abstract In this study, we propose to improve the photostability of large-area (up to 19.35 cm2) printed organic photovoltaics (OPVs) through luminescent solar concentrators (LSCs), which convert high-energy short-wavelength (λ 600 nm) photons. We investigate the impacts of the luminophore concentration and waveguide surface roughness on the power conversion efficiency (PCE) of the OPV-LSCs with sizes from 1 inch (2.54 cm) to 12 inches (30.48 cm), corresponding to front surface areas from 6.4516 cm2 to 929.0304 cm2. For the 6-inch (232.26-cm2) OPV-LSCs, the results show that a high waveguide surface roughness (Rq = 63 nm) leads to devices with a high device PCE (ηLSC = 0.93%) and wide external quantum efficiency (EQE) from 400 nm to 800 nm. Detailed edge emission analysis on the luminescent waveguides indicates an edge emission with a large fraction (>95%) of long-wavelength photons comprised of a large fraction (>25%) of near-infrared (NIR) (λ > 700 nm) light. This leads to the photostability (defined as the hours when the PCE drops by 10%) of the OPV-LSCs significantly improved to 320 h under continuous 1 sun illumination (the photostability of the OPVs is only 25 h). The approach of OPV-LSCs paves the way to practically improve the photostability of large-area printed OPVs.