Nanjing University researchers developed a perovskite-organic tandem solar cell using a novel low-bandgap acceptor to boost near-infrared light harvesting and improve photocurrent matching. The device achieved a 27.35% efficiency, while retaining 80% of its initial performance after 744 hours of continuous illumination.
Researchers at China’s Nanjing University have fabricated a perovskite-organic tandem solar cell featuring a bottom organic subcell that uses a low-bandgap (LBG) acceptor to enhance near-infrared (NIR) absorption while reducing voltage losses.
“A key factor limiting the efficiency of perovskite-organic tandem solar cells is the relatively low photocurrent density generated by the LBG organic subcells compared with their wide-bandgap (WBG) perovskite counterparts,” corresponding author Qingdong Zheng told pv magazine. “This photocurrent imbalance largely originates from the substantial overlap between the external quantum efficiency (EQE) spectra of the two subcells near the absorption edge of the perovskite layer. Therefore, the development of highly efficient near-infrared (NIR) acceptors is essential for minimizing spectral overlap, improving photocurrent matching, and ultimately enhancing tandem device performance.”
