CF3PEAI, an amphipathic passivation agent, can passivate multiple perovskite defects leading to high performance and stability of perovskite solar cells.

No abstract

It is important to reveal the luminescence mechanisms of carbon dots (CDs). Herein, CDs with two types of optical centers are synthesized from citric acid in formamide by a solvothermal method, and show high photoluminescence quantum yield reaching 42%. Their green/yellow emission exhibits pronounced vibrational structure and high resistance toward photobleaching, while broad red photoluminescence is sensitive to solvents, temperature, and UV–IR. Under UV–IR, the red emission is gradually bleached due to the photoinduced dehydration of the deprotonated surface of CDs in dimethyl sulfoxide, while this process is hindered in water. From the analysis of steady‐state and time‐resolved photoluminescence and transient absorption data together with density functional theory calculations, the green/ yellow emission is assigned to conjugated sp2‐domains (core state) similar to organic dye derivatives stacked within disk‐shaped CDs; and the broad red emission—to oxygen‐containing groups bound to sp2‐domains (surface state), whereas energy transfer from the core to the surface state can happen.

The uncontrollable dendrite growth, hydrogen evolution, and other side‐reactions, originating from the zinc anode, have severely restricted the practical application of aqueous zinc–ion batteries (ZIBs). To address these challenges, a stable solid‐electrolyte‐interface (SEI) layer is constructed through introducing sericin molecules as an electrolyte additive to modulate the Zn nucleation and overpotential of hydrogen evolution. This SEI layer increases the nucleation overpotential during Zn plating, leading to the finer‐grained, dense, and uniform Zn deposition. Meanwhile, the lower unoccupied molecular orbital molecules in SEI layer have a higher reduction potential than H2O, inhibiting hydrogen production, and subsequently suppressing the Zn dendritic and interfacial side‐reactions. Consequently, the Zn|Zn symmetric cells with sericin additives exhibit an extremely prolonged cycling lifetime of 4446 h compared with to bare Zn electrode of 53 h at 1.0 mA cm−2/1.0 mAh cm−2, and a high average Coulombic efficiency of 99.29% under a high cumulative plated capacity of 1.0 Ah cm−2 tested in Zn|Cu cells. Moreover, the assembled full cells using Na2V6O16·3H2O cathodes endure 2000 cycles with high capacity retention of 81.7% at 5.0 A g−1. This study sheds new light on modulating the process of Zn nucleation and overpotential of H2 evolution for durable Zn anode design.

No abstract