Improving the charge transport of the ternary blend active layer for efficient semitransparent organic solar cells

Semitransparent organic solar cells (OSCs) have great potential for vehicle-integrated and building-integrated photovoltaics with their rapidly increased power conversion efficiencies (PCEs). For these purposes, the efficiency of semitransparent OSCs at an adequate transparency should be further increased. In this work, a ladder-type dithienonaphthalene-based acceptor (DTNIF) with a high-lying lowest unoccupied molecular orbital energy level is used as a third component material for ternary OSCs which show increased PCEs with enlarged values in open-circuit voltage, short-circuit current and fill factor. Consequently, outstanding PCEs of 16.73% and 13.49% are achieved for the corresponding opaque and semitransparent ternary OSCs, respectively. The efficiency of 13.49% for the semitransparent OSCs at an average visible transmittance (AVT) of 22.58% is the highest reported to date, to the best of our knowledge. This work provides an effective strategy to fabricate high-performance semitransparent OSCs at high AVT values by using an excellent third component acceptor material.