Efficient Passivation with Lead Pyridine‐2‐Carboxylic for High‐Performance and Stable Perovskite Solar Cells

Abstract

Stability has become the main obstacle for the commercialization of perovskite solar cells (PSCs) despite the impressive power conversion efficiency (PCE). Poor crystallization and ion migration of perovskite are the major origins of its degradation under working condition. Here, high‐performance PSCs incorporated with pyridine‐2‐carboxylic lead salt (PbPyA2) are fabricated. The pyridine and carboxyl groups on PbPyA2 can not only control crystallization but also passivate grain boundaries (GBs), which result in the high‐quality perovskite film with larger grains and fewer defects. In addition, the strong interaction among the hydrophobic PbPyA2 molecules and perovskite GBs acts as barriers to ion migration and component volatilization when exposed to external stresses. Consequently, superior optoelectronic perovskite films with improved thermal and moisture stability are obtained. The resulting device shows a champion efficiency of 19.96% with negligible hysteresis. Furthermore, thermal (90 °C) and moisture (RH 40–60%) stability are improved threefold, maintaining 80% of initial efficiency after aging for 480 h. More importantly, the doped device exhibits extraordinary improvement of operational stability and remains 93% of initial efficiency under maximum power point (MPP) tracking for 540 h.

Extrinsic Ion Distribution Induced Field Effect in CsPbIBr2 Perovskite Solar Cells

“…Moreover, the dark current curves of PSCs (Figure S11, Supporting Information) cross‐check that SAS introduction benefitted restraining recombination. [ 51 ] Figure 5f displays the relationship between V OC and light intensity, which is in accordance with Equation () [ 52,53 ] where n is an ideal factor, κ is the Boltzmann constant, and q represents the electron charge. When the ideal factor n is equal to 1, the trap‐assisted recombination is absent, whereas n varies up to a value of 2 triggered by the trap‐assisted recombination.…”

Organic Dye Passivation for High‐Performance All‐Inorganic CsPbI1.5Br1.5 Perovskite Solar Cells with Efficiency over 14%

“…In addition, it is noted that the Pb 4f, Cs 3d, I 3d, and Br 3d peaks in wFITC shifted to higher binding energy compared with control (Figure 3c–f), indicating a decrement of electron density around these species via reduction of under‐coordinated Pb 2+ ions through interaction with FITC. [ 48 ]…”

Surface Passivation of Perovskite Film by Sodium Toluenesulfonate for Highly Efficient Solar Cells

“…Up to now several approaches have been developed to passivate the defects at the surface of perovskite film, including solvent annealing, additive engineering, post‐treatment, and surface modification . In particular, surface modification fulfilled by depositing a modifier layer atop the perovskite layer is facile with no need to change the fabrication process of the perovskite layer and thus has been extensively utilized .…”