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LIMNO scientists demonstrate new type of hybrid solar cell

© N. Guijarro / 2019 EPFL

© N. Guijarro / 2019 EPFL

Dr. Guijarro and Dr. Yao present the first demonstration of integrating CsPbI3 quantum dots into a conventional organic solar cell. The resulting performance enhancement has been published in Angewandte Chemie.

Among the emerging photovoltaic technologies, organic solar cells (OSCs) have thrived on the prospects of low-cost processing, pliability and competitive power conversion efficiencies (PCEs). However, the performance of OSCs is limited compared to comparable inorganic or hybrid technologies in part due to the restricted light harvesting afforded by conventional donor:acceptor bulk heterojunction (BHJ) blends. In contrast, the facile synthesis, solution-processability, and outstanding optoelectronic properties of emerging colloidal lead halide perovskite quantum dots (LHP QDs) makes them ideal candidates for scalable and inexpensive optoelectronic applications including photovoltaic (PV) devices. In our recent paper, LIMNO presents the first demonstration of integrating CsPbI3 QDs into a conventional organic solar cell (OSC) by embedding the LHP QDs in a donor:acceptor (PTB7-Th:PC71BM) bulk heterojunction. Optimizing the loading amount at 3 wt%, we demonstrate a power conversion efficiency of 10.8 %, which represents a 35 % increase over control devices, and is a record amongst hybrid ternary OSCs. Detailed investigation into the mechanisms behind the performance enhancement shows that increased light absorption is not a factor, but that increased exciton separation in the acceptor phase and reduced recombination are responsible. Read the full paper here.