A green solvent enables precursor phase engineering of stable formamidinium lead triiodide perovskite solar cells.

Perovskite solar cells (PSCs) offer an efficient, inexpensive alternative to current photovoltaic technologies, with the potential for manufacture via high-throughput coating methods. However, challenges for commercial-scale solution-processing of metal-halide perovskites include the use of harmful solvents, the expense of maintaining controlled atmospheric conditions, and the inherent instabilities of PSCs under operation. Here, we address these challenges by introducing a high volatility, low toxicity, biorenewable solvent system to fabricate a range of 2D perovskites, which we use as highly effective precursor phases for subsequent transformation to α-formamidinium lead triiodide (α-FAPbI), fully processed under ambient conditions.

Exploring the Impact of 1,8-Diioodoctane on the Photostability of Organic Photovoltaics.

Improving the photostability of the light-harvesting blend film in organic photovoltaics is crucial to achieving long-term operational lifetimes that are required for commercialization. However, understanding the degradation factors which drive instabilities is complex, with many variables such as film morphology, residual solvents, and acceptor or donor design all influencing how light and oxygen interact with the blend film. In this work, we show how blend films comprising a donor polymer (PBDB-T) and small molecule acceptor (PCBM or ITIC) processed with solvent additive (DIO) yield very different film morphologies, device performance, and photostability.

Reactive Passivation of Wide-Bandgap Organic-Inorganic Perovskites with Benzylamine.

While amines are widely used as additives in metal-halide perovskites, our understanding of the way amines in perovskite precursor solutions impact the resultant perovskite film is still limited. In this paper, we explore the multiple effects of benzylamine (BnAm), also referred to as phenylmethylamine, used to passivate both FACsPb(IBr) and FACsPbI perovskite compositions. We show that, unlike benzylammonium (BnA) halide salts, BnAm reacts rapidly with the formamidinium (FA) cation, forming new chemical products in solution and these products passivate the perovskite crystal domains when processed into a thin film.

Singlet Fission in Pechmann Dyes: Planar Chromophore Design and Understanding.

Singlet fission in organic chromophores holds the potential for enhancing photovoltaic efficiencies beyond the single-junction limit. The most basic requirement of a singlet fission material is that it has a large energy gap between its first singlet and triplet excited states. Identifying such compounds is not simple and has been accomplished either through computational screening or by subtle modifications of previously known fission materials.

Oligoepilepsy and lifelong seizure susceptibility in epilepsy with generalized tonic-clonic seizures alone: Experience at an adult tertiary center.

Objective: Epilepsy with generalized tonic-clonic seizures alone (GTCA) is the least studied syndrome within the idiopathic generalized epilepsy (IGE) spectrum. We characterize a large cohort of adult patients with GTCA to understand natural history and drug responsiveness.

Methods: In this retrospective single-center study using our epilepsy electronic record, we evaluated clinical characteristics, seizure outcomes, anti-seizure medication (ASM) response including seizure recurrence after ASM withdrawal, and sex differences in a cohort of GTCA patients aged ≥17 years.