Accessing Metal-Containing Species in Tin-Lead Perovskite Precursor Solutions via Molecular Strategies Guided by the Hard-Soft Acid-Base Principle.

The properties of metal-centred species in metal halide perovskite precursor solutions substantially influence the formation and evolution of colloidal particles, which in turn dictate the crystallisation process and the film quality. In this work, we assess the "hard" and "soft" Lewis acid characteristics of Sn and Pb cations as a strategy to modulate the chemical environment of these metal-containing species in mixed-metal tin-lead perovskite precursor solutions. We observe enhanced simultaneous access to both metal centres upon adding compounds with functional groups suggested by the hard-soft acid-base principle.

Dual Interface Modification for Reduced Nonradiative Recombination in n-i-p Methylammonium-Free Perovskite Solar Cells.

High defect concentrations at the interfaces are the basis of charge extraction losses and instability in perovskite solar cells. Surface engineering with organic cations is a common practice to solve this issue. However, the full implications of the counteranions of these cations for device functioning are often neglected.

Steering perovskite precursor solutions for multijunction photovoltaics.

Multijunction photovoltaics (PVs) are gaining prominence owing to their superior capability of achieving power conversion efficiencies (PCEs) beyond the radiative limit of single-junction cells, for which improving narrow-bandgap (NBG) tin-lead perovskites is critical for thin-film devices. Here, with a focus on understanding the chemistry of tin-lead perovskite precursor solutions, we find that Sn(II) species dominate interactions with precursors and additives and uncover the exclusive role of carboxylic acid in regulating solution colloidal properties and film crystallization and ammonium in improving film optoelectronic properties. Materials that combine these two functional groups, amino acid salts, considerably improve the semiconducting quality and homogeneity of perovskite films, surpassing the effect of the individual functional groups when introduced as part of separate molecules.

Buried hole-selective interface engineering for high-efficiency tin-lead perovskite solar cells with enhanced interfacial chemical stability.

Mixed Sn-Pb perovskites are attracting significant attention due to their narrow bandgap and consequent potential for all-perovskite tandem solar cells. However, the conventional hole transport materials can lead to band misalignment or induce degradation at the buried interface of perovskite. Here we designed a self-assembled material 4-(9H-carbozol-9-yl)phenylboronic acid (4PBA) for the surface modification of the substrate as the hole-selective contact.

Suppressed Defects by Functional Thermally Cross-Linked Fullerene for High-Efficiency Tin-Lead Perovskite Solar Cells.

Mixed tin-lead (Sn-Pb) perovskites have attracted the attention of the community due to their narrow bandgap, ideal for photovoltaic applications, especially tandem solar cells. However, the oxidation and rapid crystallization of Sn and the interfacial traps hinder their development. Here, cross-linkable [6,6]-phenyl-C-butyric styryl dendron ester (C-PCBSD) is introduced during the quenching step of perovskite thin film processing to suppress the generation of surface defects at the electron transport layer interface and improve the bulk crystallinity.

Inhibiting Interfacial Nonradiative Recombination in Inverted Perovskite Solar Cells with a Multifunctional Molecule.

Interface-induced nonradiative recombination losses at the perovskite/electron transport layer (ETL) are an impediment to improving the efficiency and stability of inverted (p-i-n) perovskite solar cells (PSCs). Tridecafluorohexane-1-sulfonic acid potassium (TFHSP) is employed as a multifunctional dipole molecule to modify the perovskite surface. The solid coordination and hydrogen bonding efficiently passivate the surface defects, thereby reducing nonradiative recombination.

Innovative pathological network-based multitarget approaches for Alzheimer's disease treatment.

Alzheimer's disease (AD) is the most prevalent neurodegenerative disease and is a major health threat globally. Its prevalence is forecasted to exponentially increase during the next 30 years due to the global aging population. Currently, approved drugs are merely symptomatic, being ineffective in delaying or blocking the relentless disease advance.

Charge Carrier Regulation for Efficient Blue Quantum-Dot Light-Emitting Diodes Via a High-Mobility Coplanar Cyclopentane[]thiopyran Derivative.

The performance of blue quantum dot light-emitting diodes (QLEDs) is limited by unbalanced charge injection, resulting from insufficient holes caused by low mobility or significant energy barriers. Here, we introduce an angular-shaped heteroarene based on cyclopentane[]thiopyran (C-SS) to modify the hole transport layer poly--vinylcarbazole (PVK), in blue QLEDs. C-SS exhibits high hole mobility and conductivity due to the π···π and S···π interactions.

Narrow Bandgap Metal Halide Perovskites for All-Perovskite Tandem Photovoltaics.

All-perovskite tandem solar cells are attracting considerable interest in photovoltaics research, owing to their potential to surpass the theoretical efficiency limit of single-junction cells, in a cost-effective sustainable manner. Thanks to the bandgap-bowing effect, mixed tin-lead (Sn-Pb) perovskites possess a close to ideal narrow bandgap for constructing tandem cells, matched with wide-bandgap neat lead-based counterparts. The performance of all-perovskite tandems, however, has yet to reach its efficiency potential.

Anchoring Charge Selective Self-Assembled Monolayers for Tin-Lead Perovskite Solar Cells.

Self-assembled monolayers (SAMs) have displayed great potential for improving efficiency and stability in p-i-n perovskite solar cells (PSCs). The anchoring of SAMs at the conductiv metal oxide substrates and their interaction with perovskite materials must be rationally tailored to ensure efficient charge carrier extraction and improved quality of the perovskite films. Herein, SAMs molecules with different anchoring groups and spacers to control the interaction with perovskite in the p-i-n mixed Sn-Pb PSCs are selected.

Biotoxicity of Halide Perovskites in Mice.

Halide perovskites are crystalline semiconductors with exceptional optoelectronic properties, rapidly developing toward large-scale applications. Lead (II) (Pb ) is the core element used to prepare halide perovskites. Pb can displace key 2+ elements, including calcium, zinc and iron, that regulate vital physiological functions.

Tin Halide Perovskite Solar Cells with Open-Circuit Voltages Approaching the Shockley-Queisser Limit.

The power conversion efficiency of tin-based halide perovskite solar cells is limited by large photovoltage losses arising from the significant energy-level offset between the perovskite and the conventional electron transport material, fullerene C. The fullerene derivative indene-C bisadduct (ICBA) is a promising alternative to mitigate this drawback, owing to its superior energy level matching with most tin-based perovskites. However, the less finely controlled energy disorder of the ICBA films leads to the extension of its band tails that limits the photovoltage of the resultant devices and reduces the power conversion efficiency.

Enabling water-free PEDOT as hole selective layer in lead-free tin perovskite solar cells.

Metal halide perovskites are set to revolutionise photovoltaic energy harvesting owing to an unmatched combination of high efficiency and low fabrication costs. However, to improve the sustainability of this technology, replacing lead with less toxic tin is highly desired. Tin halide perovskites are approaching 15% in power conversion efficiency (PCE), mainly employing PEDOT:PSS as a hole-selective layer.

Synergistic Surface Modification of Tin-Lead Perovskite Solar Cells.

Interfaces in thin-film photovoltaics play a pivotal role in determining device efficiency and longevity. In this work, the top surface treatment of mixed tin-lead (≈1.26 eV) halide perovskite films for p-i-n solar cells is studied.

Pyridine Controlled Tin Perovskite Crystallization.

Controlling the crystallization of perovskite in a thin film is essential in making solar cells. Processing tin-based perovskite films from solution is challenging because of the uncontrollable faster crystallization of tin than the most used lead perovskite. The best performing devices are prepared by depositing perovskite from dimethyl sulfoxide because it slows down the assembly of the tin-iodine network that forms perovskite.

Lights and Shadows of DMSO as Solvent for Tin Halide Perovskites.

In 2020 dimethyl sulfoxide (DMSO), the ever-present solvent for tin halide perovskites, was identified as an oxidant for Sn . Nonetheless, alternatives are lacking and few efforts have been devoted to replacing it. To understand this trend it is indispensable to learn the importance of DMSO on the development of tin halide perovskites.

Challenges in tin perovskite solar cells.

Perovskite solar cells are the rising star of third-generation photovoltaic technology. With a power conversion efficiency of 25.5%, the record efficiency is close to the theoretical maximum efficiency of a single-junction solar cell.

Comparing diagnostic sensitivity of different needle sizes for lymph nodes suspected of lung cancer in endobronchial ultrasound transbronchial needle aspiration: Systematic review and meta-analysis.

Background: Endobronchial ultrasound transbronchial needle aspiration (EBUS-TBNA) is a safe and minimally invasive procedure for evaluating hilar and mediastinal lymph nodes. The reported sensitivity and specificity of EBUS-TBNA are 95% and 97%, respectively. A comparison of diagnostic sensitivity for lymph nodes suspected of lung cancer according to needle size in EBUS-TBNA is needed.

Physician Satisfaction With Telemedicine During the COVID-19 Pandemic: The Mayo Clinic Florida Experience.

Objective: To evaluate physician perceptions and attitudes toward telemedicine use at a tertiary care academic institution in northeast Florida during the coronavirus disease 2019 pandemic.

Patients And Methods: An anonymous 38-question cross-sectional survey was developed using Qualtrics survey software (Qualtrics) and e-mailed to all staff physicians from all specialty disciplines at Mayo Clinic in Florida. The survey was open from August 17, 2020, through September 1, 2020.

Precautionary strategy for high-risk airway bleeding cases during robotic-assisted bronchoscopy.

Bronchoscopy in thrombocytopenic patients remains a controversial topic as traditionally varying platelet thresholds have been stablished as "safe," ranging from 20,000 to 50,000. A lower threshold may be safe for a routine airway inspection with bronchoalveolar lavage but will be far from safe for more invasive interventions such as needle biopsy, transbronchial biopsy, or cryo-biopsy. Currently, a minimal platelet threshold during robotic-assisted bronchoscopy (RAB) has not been established.