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Efficient control of the perovskite crystallization and passivation of the defects at the surface and grain boundaries of perovskite films have turned into the most important strategies to restrain charge recombination toward high-performance and long-term stability of perovskite solar cells (PSCs). In this paper, we employed a small amount of natural vitamin B (carnitine) with dual functional groups in the MAPbI3 precursor solution to simultaneously passivate the positive- and negative-charged ionic defects, which would be beneficial for charge transport in the PSCs. In addition, such methodology can efficiently ameliorate crystallinity with texture, better film morphology, high surface coverage, and longer charge carrier lifetime, as well as induce preferable energy level alignment. Benefiting from these advantages, the power conversion efficiency of PSCs significantly increases from 16.43 to 20.12% along with not only a higher open-circuit voltage of 1.12 V but also an outstanding fill factor of 82.78%.

A series of tailor-made highly efficient and near-infrared (NIR) porphyrin-based acceptors is designed and synthesized for fullerene-free bulk-heterojunction (BHJ) organic solar cells. Constructing BHJ active layers using a PTB7-Th donor and porphyrin acceptors (P-x), which have complementary absorption, accomplishes panchromatic photon-to-current conversion from 300 to 950 nm. Our study shows that side chains of the porphyrin acceptors fairly influence the molecular ordering and nanomorphology of the BHJ active layers. Significantly, the porphyrin acceptor with four dodecoxyl side chains (P-2) achieves an open-circuit voltage (VOC) of 0.80 V, short-circuit current density (JSC) of 13.94 mA cm-2, fill factor of 64.8%, and overall power conversion efficiency of 7.23%. This great performance is attributable to the ascendant light-harvesting capability in the visible and near-infrared region, a high-lying LUMO energy level, a relatively high and more balanced carrier mobilities, and more ordered face-on molecular packing, which is beneficial for obtaining high VOC and JSC.