With the world's growing population, the demand for food and electricity is increasing rapidly. To meet these demands, the agricultural and energy sectors need to work together to achieve sustainable development. Agrivoltaics is one of the promising approaches that combines the production of crops and renewable energy generation in the same land footprint. However, the use of conventional opaque solar panels in agrivoltaic systems creates shading effects, being unable to share the solar spectrum, given that plants absorb only >1.7 eV photons whilst silicon (or other inorganic) solar cells absorb all photon energies above the near IR. To overcome this issue, low-cost semi-transparent photovoltaic modules produced using scalable manufacturing offer an exciting alternative. Such cells enable wavelengths between 400 and 700 nm, which is referred to as photosynthetically active radiation (PAR) to pass through to the crop. Thus, Organic Photovoltaics (OPV) have gained significant attention due to their ability to harness photons in the near-infrared and ultraviolet spectra while allowing visible light to pass through, providing high transparency.

The current state-of-the art power conversion efficiency (PCE) of OPVs exceeds 20% for a single junction OPV¹and reaches 11% for semitransparent based OPV devices², following rapid improvement in recently developed non-fullerene small-molecules acceptors (NFAs) to replace fullerene-counterpart. Moreover, high potential PCEs are offered by a ternary system where either the third component acts as an additional donor or additional acceptors that serve to extend the range of absorption and can also tune material properties. Interestingly, the incorporation of the third counterpart can regulate the accumulation and orientation of the molecule, as well as the phase separation of donor and acceptor, providing high crystallinity and ordered molecular stacking that can improve the charge transport and inhibit the bimolecular recombination through well optimized phase separation³.

Furthermore, most research on ternary strategies is based on the bulk hetero junction (BHJ) system, which is sensitive to material properties and processing conditions. This makes it difficult to control other important morphological parameters, such as molecular orientation and domain purity as it further complicates the morphological regulation, especially the D:A orientation in the vertical direction of blend films which is mainly related to the charge transport and collection⁴. Thus, to tailor vertical phase distribution efficiently, the sequential deposition or named layer by layer (LBL) deposition approach of the D and A materials is considered as a promising alternative to the BHJ⁵.

Hence, I have developed a novel OPV structure, introducing a perovskite quantum dots (PQDs) interlayer sandwiched between the organic semiconductor donor and the NFA layers using LBL deposition approach, resulting in enhancement in the performance of OPV devices by 11% ( from PCE=16.6% for the pristine binary OPV to PCE= 18.8% for the QDs-based ternary OPV) along with 99 % performance retention after 3 months of storage compared to only 30% for the bilayer devices without PQDs. This unique structure allows for the LBL preferred vertical phase separation and well-controlled D/QDs/A interface film morphology, exhibiting efficient charge transport and extraction properties. Interestiingly, from the perspective of the agrivoltaic application, the PQD interlayer (third component) does not absorb much light in the visible region, allowing it to be transmitted to the plants without influencing the crop yields.

In summary, the semitransparency and promising PCE along with the cost-effective, eco-friendly processing, are promising selling points of this OPV technology for the agrivoltaic system relative to traditional PV technologies.