Reducing the Trap Density in MAPbI Based Perovskite Solar Cells via Bromide Substitution.

The past decade has witnessed tremendous advancement in the field of halide perovskite (PSK) as a choice of material for high-performing solar cells fabrication. Here, we investigate the impact of the halide exchange through N-bromosuccinimide (NBS) treatment in MAPbI based solar cells. We observed the partial halide exchange (I to Br ) or the filling of halide (X ) vacancy upon treatment of different NBS concentrations experimentally by spectroscopic and diffractogram studies.

Deciphering the Orientation of the Aromatic Spacer Cation in Bilayer Perovskite Solar Cells through Spectroscopic Techniques.

Slowing the degradation of perovskite-based solar cells (PSCs) is of substantial interest. We engineered the surface by introducing a hydrophobic overlayer on a three-dimensional (3D) perovskite using fluorinated or nonfluorinated aryl ammonium cation spacers. The placement of a fluoroarene cation allows the formation of a bilayer structure, that is, layered/3D perovskites.

Substance and shadow of formamidinium lead triiodide based solar cells.

The current decade has witnessed a surge of progress in the investigation of methyl ammonium lead iodide (MAPbI3) perovskites for solar cell fabrication due to their intriguing electro-optical properties, despite the intrinsic degradation of the material that has restricted its commercialisation. As a promising alternative, solar cells based on its formamidinium analogue, FAPbI3, are currently being actively pursued for having demonstrated a certified efficiency of 24.4%, while the room-temperature conversion to a non-perovskite δ-phase impedes its further commercialisation, and strategies have been adopted to overcome this phase instability.

Aggregation-Induced and Polymorphism-Dependent Thermally Activated Delayed Fluorescence (TADF) Characteristics of an Oligothiophene: Applications in Time-Dependent Live Cell Multicolour Imaging.

Typically, molecules with a twisted donor-acceptor (D-A) architecture have been exploited for constructing thermally activated delayed fluorescence (TADF) materials. Herein, we report the first example of a thiophene-based thermally activated delayed fluorescent molecule without a D-A architecture. Compound 1 (2,5-bis(2,2-di(thiophen-2-yl)vinyl)thiophene) is conformationally flexible and shows weak fluorescence in the solution state but displays bright TADFin both condensed and solid states.