High‐Efficiency Semi‐Transparent Organic Solar Cells Using Pentacyclic Aromatic Lactam‐Containing Terpolymer Strategy for Eco‐Friendly Greenhouse Application

Abstract

Semitransparent organic solar cells (ST‐OSCs) offer unique features such as spectral tunability and see‐through function, giving them great potential in photovoltaic (PV) agriculture. However, the combination of sufficient average visible transmittance (AVT) and high power conversion efficiency (PCE) with eco‐friendly device fabrication has always been a key issue. Herein, a simple but effective strategy by incorporating pentacyclic aromatic lactam acceptor unit (TPTI) in copolymer donors for toluene processed high‐efficiency ST‐OSCs is performed. The comparisons between D18‐ and DEH‐X‐based ST‐OSCs demonstrate the effect of TPTI inserting on the polymer main skeleton can not only lower the energy level, improve the processability in nonhalogen solvent, tune the ideal morphology for efficient charge dissociation, but also control a photon transport window suitable for plant absorption. Therefore, the resulting OSCs processed with toluene exhibit a PCE of 14.6% with an AVT of 22%, which represents one of the highest values for ST‐OSCs made from nonhalogenated solvents. What's more, it is found that plant growth under ST‐OSCs filtered light is comparable with that under natural light. Herein, a guide for developing high‐performance ST‐OSCs is provided and the prospect of ST‐OSCs for green manufacturing PV greenhouse application is demonstrated.