High-performance semi-transparent organic solar cells driven by the dipole-controlled optoelectrical response of bilateral self-assembled monolayer strategy

A bilateral self-assembled monolayer (SAM) strategy is proposed to improve the performance of both opaque/translucent and rigid/flexible organic solar cells (OSCs), which have great potential for various high-value applications such as portable, building-integrated and vehicle-integrated photovoltaics. By applying the dipole-controlled SAMs to both ITO/ZnO and ZnO/active layer interfaces, the work function of the ZnO electron transport layer was reduced, which improved charge transport and reduced carrier recombination at the interface. The opaque OSCs with the bilateral SAM demonstrated significant performance improvement with power conversion efficiencies (PCEs) reaching 17.20% and 16.96% for rigid and flexible OSCs. When used in semi-transparent OSCs together with MoO3/Ag/MoO3 electrode, in semi-transparent (ST) OSCs, PCE and average visible transmittance (AVT) can be improved simultaneously, and 10.37% PCE and 36.27% AVT demonstrate a remarkable light utilization efficiency (LUE) of 3.85%. Finally, the large area (10 × 10 cm2) ST-OSC module was fabricated and demonstrated a PCE of 8.17% and LUE of 2.5%, among the best-reported values for inverted module devices. The developed bilateral SAM strategy can be useful in developing high-performance OSCs of both opaque/translucent and rigid/flexible types for various practical applications.