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Making highly efficient and stable perovskite solar cells (PSCs) are often based on the processing techniques, band gap of the material and effective interface charge separation. The efficiency of PSCs can be enhanced through several methods including the utilization of a solar-friendly absorber, interface passivation and the implementation of multi-junction spectrally matched absorbers or bilayered phase homojunction (BPHJ) consisting of identical absorbers. Here, we demonstrated BPHJ concept by stacking identical compositions of highly efficient and stable FA 0.15 MA 0.85 PbI 3 perovskite absorbers adopting solution process (SP) and thermal evaporation (TEV) techniques. We successfully achieved FA 0.15 MA 0.85 PbI 3 (SP)/FA 0.15 MA 0.85 PbI 3 -(TEV) based BPHJ normal n-i-p devices, which significantly crossing 22. % PCE. These improvement stems from effective deposition method for achieving high-quality FA 0.15 MA 0.85 PbI 3 -based BPHJ enabling smooth charge transfer at the interfaces. The resulting BPHJ-based champion device achieve a 22.13 % PCE and retain >95 % its original efficiency over 1000 hours. [Display omitted] [ABSTRACT FROM AUTHOR]

Two-dimensional (2D) nanostructures are attractive candidates for electrocatalytic applications owing to their excellent mechanical flexibility and large exposed surfaces. In this work, we present ultra-thin 2D NiO porous nanosheets prepared by a simple, economical and green experimental method (hydrothermal, freeze-drying, and sintering) as efficient electrocatalysts for direct methanol fuel cell (DMFC) application. Benefiting from the ultra-thin 2D framework and porous nanostructure, the 550-NiO catalyst (annealed at 550 °C) exhibit higher current density (12.54mA cm−2) and faster charge transfer in the catalytic process, due to its abundant solid state redox couples (Ni2+/Ni3+= 0.991), suitable oxygen defects and surface coverage of redox species (2.90 × 10−7mol cm−2). First-principles density functional theory calculations were employed to provide mechanistic insights into the methanol oxidation reaction over the NiO catalyst via methanol dehydrogenation to CO involving O–H and C–H bond scissions, and subsequently, CHO oxidation with OH. The most plausible reaction pathway of methanol oxidation on NiO (100) is predicted to be CH 3 OH → CH 3 O → CH 2 O → CHO → CHOOH → COOH → CO 2. The reported facile, simple, low-cost and method provides an avenue for the rational design and synthesis of 2D NiO porous nanostructured electrode materials for DMFC and beyond. Graphical Abstract [Display omitted]. [ABSTRACT FROM AUTHOR]

Herein, we demonstrate the single-step microwave radiation assisted approach to develop Nitrogen (N) and Phosphorous (P) co-doped carbon quantum dots (NP-CQD). The developed NP-CQD showed enhancement in visible light photocatalytic activity towards methylene blue dye degradation than that of N-CQD and P-CQD due to creation of energy states and reduced work function as estimated by Ultraviolet photoelectron spectroscopy and corroborated by first-principles Density Functional Theory (DFT) calculations. • N and P were co-doped to CQD by microwave radiation assisted method. • NP-CQD showed enhancement in visible light photocatalytic activity. • DFT calculations showed the decrease in work function of NP-CQD. • P-CQD showed improved photocatalytic activity than N-CQD. [ABSTRACT FROM AUTHOR]