Identification of lead vacancy defects in lead halide perovskites.

Perovskite photovoltaics advance rapidly, but questions remain regarding point defects: while experiments have detected the presence of electrically active defects no experimentally confirmed microscopic identifications have been reported. Here we identify lead monovacancy (V) defects in MAPbI (MA = CHNH) using positron annihilation lifetime spectroscopy with the aid of density functional theory. Experiments on thin film and single crystal samples all exhibited dominant positron trapping to lead vacancy defects, and a minimum defect density of ~3 × 10 cm was determined.

Oral health-related quality of life in oral cancer patients: systematic review and meta-analysis.

The purpose of this meta-analysis was to evaluate the impact of oral health on quality of life in oral cancer patients (OCPs). PubMed, Scopus and Web of Science databases were searched for publications on oral health-related quality of life (OHRQoL) in OCP and the information was extracted according to the PRISMA guidelines. A random effect model was used to obtain the pooled standard mean differences of Oral Health Impact Profile (OHIP)-14 questionnaire responses in meta-analysis.

Orientation-Controlled (0) PbI Crystallites Using a Novel Pb-Precursor for Facile and Quick Sequential MAPbI Perovskite Deposition.

Organic-inorganic hybrid lead halide perovskites have shown significant progress in the last few years having achieved efficiencies over 25% at the lab scale. The sequential deposition technique has provided a robust approach in the perovskite film fabrication. However, obtaining a reproducible and quality perovskite film has always been challenging because of the highly crystalline and ordered (001) oriented underlying PbI film.

A systematic scoping review on utility of cytomorphometry in the detection of dysplasia in oral potentially malignant disorders.

Background: Oral exfoliative cytology is simple, non-invasive, inexpensive tools prone to subjective bias. Objective computer-based quantitative cytomorphometry technique was developed in last few decades to overcome its limitation. However, there is no consensus about the utility of cytomorphometry as a routine screening tool for early detection of dysplastic changes.

Recycling of Perovskite Films: Route toward Cost-Efficient and Environment-Friendly Perovskite Technology.

Mixed organic-inorganic halide perovskite solar cells have reached unprecedentedly high efficiency in a short term. Two major challenges in its large-scale deployment is the material instability and hazardous lead waste. Several studies have identified that lead replacement with its other alternatives does not show the similar assurance.

Unraveling the Effect of Crystal Structure on Degradation of Methylammonium Lead Halide Perovskite.

Despite the remarkable efficiencies of perovskite solar cells, moisture instability has still been the major constraint in the technology deployment. Although, some research groups have discussed the possible mechanisms involved in the perovskite degradation, no broader understanding has been developed so far. Here, we demonstrate that the crystal orientation of perovskite film plays a major role in its degradation.

Partial oxidation of the absorber layer reduces charge carrier recombination in antimony sulfide solar cells.

We investigate the effect of a post heat treatment of the absorber layer in air for antimony sulfide (SbS) sensitized solar cells. Phenomenologically, exposing the SbS surface of sensitised solar cells to air at elevated temperatures is known to improve device performance. Here, we have investigated the detailed origins of this improvement.

Efficient room temperature aqueous Sb2S3 synthesis for inorganic-organic sensitized solar cells with 5.1% efficiencies.

Sb2S3 sensitized solar cells are a promising alternative to devices employing organic dyes. The manufacture of Sb2S3 absorber layers is however slow and cumbersome. Here, we report the modified aqueous chemical bath synthesis of Sb2S3 absorber layers for sensitized solar cells.

Ultrasmooth organic-inorganic perovskite thin-film formation and crystallization for efficient planar heterojunction solar cells.

To date, there have been a plethora of reports on different means to fabricate organic-inorganic metal halide perovskite thin films; however, the inorganic starting materials have been limited to halide-based anions. Here we study the role of the anions in the perovskite solution and their influence upon perovskite crystal growth, film formation and device performance. We find that by using a non-halide lead source (lead acetate) instead of lead chloride or iodide, the perovskite crystal growth is much faster, which allows us to obtain ultrasmooth and almost pinhole-free perovskite films by a simple one-step solution coating with only a few minutes annealing.