How to Stabilize the Current of Efficient Inverted Flexible Perovskite Solar Cells at the Maximum Power Point.

Inverted flexible perovskite cells (fPSCs) have attracted much attention for their high efficiency and power per weight. Still, the steady-state output is one of the critical factors for their commercialization. In this paper, it is found that the steady-state current of inverted fPSCs based on nickel oxide nanoparticles (n-NiO) continuously decreases under light illumination.

Phase-Engineering of Layered Nickel Hydroxide for Synthesizing High-Quality NiO Nanocrystals for Efficient Inverted Flexible Perovskite Solar Cells.

Nickel oxide (NiO) nanocrystals have been widely used in inverted (p-i-n) flexible perovskite solar cells (fPSCs) due to their remarkable advantages of low cost and outstanding stability. However, anion and cation impurities such as NO widely exist in the NiO nanocrystals obtained from calcinated nickel hydroxide (Ni(OH)). The impurities impair the photovoltaic performance of fPSCs.

Green-Solvent Engineering for Depositing Qualified Phenyl-C61-butyl Acid Methyl Ester Films for Inverted Flexible Perovskite Solar Cells.

Flexible perovskite solar cells (fPSCs) with the inverted structure (p-i-n structure) show a promising commercialization future, owing to their lightweight and high efficiencies. Phenyl-C61-butyric-acid methyl ester (PCBM) is widely used as the n-type material due to its excellent conductivity and solvent processability. However, the commonly used chlorobenzene (CB), as the solvent of PCBM solution, is well recognized as a halogenated contaminant in the environment and is harmful to human health.

Composition Stoichiometry of CsAgBiBr Films for Highly Efficient Lead-Free Perovskite Solar Cells.

Addressing the toxicity issue in lead-based perovskite compounds by seeking other nontoxic candidate elements represents a promising direction to fabricate lead-free perovskite solar cells. Recently, CsAgBiBr double perovskite achieved by replacing two Pb with Ag and Bi in the crystal lattice has drawn much attention owing to the convenient substitution of its chemical compositions. Herein, the dependence of the optoelectronic properties and corresponding photovoltaic performance of CsAgBiBr thin films on the deposition methods of vacuum sublimation and solution processing is investigated.

84% efficiency improvement in all-inorganic perovskite light-emitting diodes assisted by a phosphorescent material.

A novel mixed perovskite emitter layer is applied to design all-inorganic cesium lead halide perovskite light-emitting diodes (PeLEDs) with high electroluminescence (EL) performance, by combining CsPbBr with iridium(iii)bis[2-(4',6'-difluorophenyl)pyridinato-N,C']-picolinate (FIrpic), where FIrpic is a phosphorescent material with very high internal quantum efficiency (IQE) approaching 100%. The CsPbBr:FIrpic PeLEDs show a maximum luminance of 5486 cd m, and an external quantum efficiency of 0.47%, which are 1.

Highly Efficient Perovskite Light-Emitting Diodes Incorporating Full Film Coverage and Bipolar Charge Injection.

Solution-processable organometal halide perovskites have been emerging as very promising materials for light-emitting diodes (LEDs) because of their high color purity, low cost, and high photoluminescence quantum yield. However, their electroluminescent performance is still limited by incomplete surface coverage and inefficient charge injection into the perovskite. Here, we demonstrate highly efficient perovskite LEDs (PeLEDs) incorporating full film coverage and bipolar charge injection within the active layer by introducing perovskite precursor poly(9-vinylcarbazole):1,3,5-tris(1-phenyl-1H-benzimidazol-2-yl)benzene (PVK:TPBi) toluene solution into CHNHPbBr N,N-dimethylformamide solution.