Abstract: A method including depositing a lead halide precursor ink onto a substrate; drying the lead halide precursor ink to form a first thin film; annealing the first thin film; and forming a perovskite material layer, wherein forming the perovskite material layer includes: depositing a benzylammonium halide precursor ink onto the first thin film; drying the benzylammonium halide precursor ink; depositing a formamidinium halide precursor ink onto the benzylammonium halide precursor ink; drying the formamidinium halide precursor ink to form a second thin film; and annealing the second thin film.

Abstract: A composition that includes a binding material and a lead-sequestration compound attached to the binding material, the lead-sequestration compound including one or more lead binding groups selected from the group consisting of: a carboxylate, a phosphate, a sulfide, a sulfate, and any combination thereof.

Abstract: A method for producing an organic non-fullerene electron transport compound includes mixing naphthalene-1,4,5,8-tetracarboxylic dianhydride and an amine compound in dimethylformamide. The method also includes heating the mixture to a temperature greater than or equal to 70° and less than or equal to 160° C. for an amount of time greater than or equal to 1 hour and less than or equal to 24 hours. The method further includes isolating an organic non-fullerene electron transport compound reaction product.

Abstract: A method for producing an organic non-fullerene electron transport compound includes mixing naphthalene-1,4,5,8-tetracarboxylic dianhydride and an amine compound in dimethylformamide. The method also includes heating the mixture to a temperature greater than or equal to 70° and less than or equal to 160° C. for an amount of time greater than or equal to 1 hour and less than or equal to 24 hours. The method further includes isolating an organic non-fullerene electron transport compound reaction product.

Abstract: A method for producing an organic non-fullerene electron transport compound includes mixing naphthalene-1,4,5,8-tetracarboxylic dianhydride and an amine compound in dimethylformamide. The method also includes heating the mixture to a temperature greater than or equal to 70° and less than or equal to 160° C. for an amount of time greater than or equal to 1 hour and less than or equal to 24 hours. The method further includes isolating an organic non-fullerene electron transport compound reaction product.

Abstract: The disclosed embodiments provide a system for estimating transit times. During operation, the system selects one or more transit time thresholds that fall within a transit time preference for a user. Next, the system obtains one or more isochrones representing the one or more transit time thresholds for a starting point associated with the user and a mode of transportation. The system then compares locations of a set of entities to the one or more isochrones to calculate transit times between the starting point and the set of entities. Finally, the system outputs, based on the transit times, one or more recommendations comprising one or more entities in the set of entities that meet the transit time preference.