2D Ruddlesden−Popper (2DRP) tin (Sn) perovskite solar cells (PSCs) play an irreplaceable role in advancing the commercialization of perovskite-based photovoltaic devices due to their low toxicity and improved stability. However, the efficiency of 2DRP Sn PSCs has not made a breakthrough owing to incompletely oriented crystal growth and poor film morphology, which is limited by a complex and uncontrollable crystallization process. Here, we first introduce the mixed spacer organic cations [n-butylamine (BA) and phenylethylamine (PEA)] in 2DRP Sn perovskite to control the crystallization process. We find that when the BA + and PEA + cowork to form [(BA 0.5 PEA 0.5 ) 2 FA 3 Sn 4 I 13 ] 2DRP perovskites, the intermediate phase impeding the homogeneous and ordered nucleation of the crystal is suppressed effectively, thus enabling a high-quality film morphology and improved crystal orientation. Benefitting from it, the power conversion efficiency (PCE) is improved to 8.82%, which is the highest one among the 2DRP Sn PSCs as far as we known.

No abstract

No abstract

No abstract

No abstract

An organometallic Ir complex exhibited enhanced photovoltaic performance compared to an organic ligand.

A novel chiral separation membrane was fabricated by assembling l-cysteine (l-Cys)-modified graphene oxide sheets. l-Cys modification leads to an enantiomer separation membrane with an accessible interlayer spacing of 8 Å, which allows high solvent permeability. In the racemate separation experiments under isobaric conditions, the enantiomeric excess (ee) values of alanine (Ala), threonine (Thr), tyrosine (Tyr), and penicillamine (Pen) racemates in the permeation solution were 43.60, 44.11, 27.43, and 46.44%, respectively. In the racemate separation experiments under negative pressure, the separation performances of Ala, Thr, and Tyr were still maintained, and the enantiomeric excess (ee) values of the filtrate after separation were 56.80, 54.57, and 32.34%, respectively. These results indicate that the as-prepared GO-Cys membrane has a great practical value in the field of enantiomer separation.

It is demonstrated that oxidative debris can be separated and largely removed during the surfactant assisted phase transfer of graphene oxide from a water/ethanol mixture to dichlorobenzene. The new procedure described provides a facile method to obtain monolayer dispersed graphene sheets in a nonpolar solvent via solvothermal reduction of graphene oxide accompanied by an effective purification process.