Spontaneous formation of robust two-dimensional perovskite phases.

The two-dimensional on three-dimensional (2D/3D) perovskite bilayer heterostructure can improve the stability and performance of perovskite solar cells. We show that the 2D/3D perovskite stack in a device evolves dynamically during its end-of-life decomposition. Initially phase-pure 2D interlayers can evolve differently, resulting in different device stabilities.

A 2D/3D Heterostructure Perovskite Solar Cell with a Phase-Pure and Pristine 2D Layer.

Interface engineering plays a critical role in advancing the performance of perovskite solar cells. As such, 2D/3D perovskite heterostructures are of particular interest due to their optoelectrical properties and their further potential improvements. However, for conventional solution-processed 2D perovskites grown on an underlying 3D perovskite, the reaction stoichiometry is normally unbalanced with excess precursors.

Stabilization of Organic Cations in Lead Halide Perovskite Solar Cells Using Phosphine Oxides Derivatives.

Preventing ion migration in perovskite photovoltaics is key to achieving stable and efficient devices. The activation energy for ion migration is affected by the chemical environment surrounding the ions. Thus, the migration of organic cations in lead halide perovskites can be mitigated by engineering their local interactions, for example through hydrogen bonding.

Rational Design of a Chemical Bath Deposition Based Tin Oxide Electron-Transport Layer for Perovskite Photovoltaics.

Chemical bath deposition (CBD) is widely used to deposit tin oxide (SnO ) as an electron-transport layer in perovskite solar cells (PSCs). The conventional recipe uses thioglycolic acid (TGA) to facilitate attachments of SnO particles onto the substrate. However, nonvolatile TGA is reported to harm the operational stability of PSCs.

Infrared Spectroscopic and Kinetic Characterization on the Photolysis of Nitrite in Alcohol-Containing Aqueous Solutions.

Nitrite is regarded as a potential OH and NO precursor in aqueous solution upon ultraviolet photolysis. A step-scan Fourier-transform interferometer was employed to collect the transient infrared difference spectra upon excitation of the sodium nitrite aqueous solution in the presence of methanol and ethanol upon 355 nm pulsed excitation. The photolytic intermediates were proposed to be NO and NO via the direct dissociation from NO and the rapid reaction of OH and NO, respectively.

Does Tetrahydrofuran (THF) Behave like a Solvent or a Reactant in the Photolysis of Thionyl Chloride (ClSO) in Cyclohexane? A Transient Infrared Difference Study.

The photolysis of thionyl chloride (ClSO) in pure cyclohexane (cHex) and in cHex with a small amount of tetrahydrofuran (THF) irradiated with 266 nm pulsed laser was investigated using time-resolved step-scan Fourier-transform spectroscopy. The density functional theory B3LYP, with the conductor-like polarizable continuum model to account for the effects of solvents, was employed to predict the molecular parameters of the relevant species. Monitoring the wavenumbers and infrared absorbances attributed to the [S,O] species and accounting for the stoichiometry revealed SO to be the major oxygen-containing end product for the thermal decomposition of ClSO.