Pinhole-free perovskite films for efficient solar modules

We report on a perovskite solar module with an aperture area of 4 cm2 and geometrical fill factor of 91%. The module exhibits an aperture area power conversion efficiency (PCE) of 13.6% from a current–voltage scan and 12.6% after 5 min of maximum power point tracking. High PCE originates in pinhole-free perovskite films made with a precursor combination of Pb(CH3CO2)2·3H2O, PbCl2, and CH3NH3I

Strategy for large???scale monolithic Perovskite/Silicon tandem solar cell: A review of recent progress

For any solar cell technology to reach the final mass-production/commercialization stage, it must meet all technological, economic, and social criteria such as high efficiency, large-area scalability, long-term stability, price competitiveness, and environmental friendliness of constituent materials. Until now, various solar cell technologies have been proposed and investigated, but only crystalline silicon, CdTe, and CIGS technologies have overcome the threshold of mass-production/commercialization. Recently, a perovskite/silicon (PVK/Si) tandem solar cell technology with high efficiency of 29.1% has been reported, which exceeds the theoretical limit of single-junction solar cells as well as the efficiency of stand-alone silicon or perovskite solar cells. The International Technology Roadmap for Photovoltaics (ITRPV) predicts that silicon-based tandem solar cells will account for about 5% market share in 2029 and among various candidates, the combination of silicon and perovskite is the most likely scenario. Here, we classify and review the PVK/Si tandem solar cell technology in terms of homo- and hetero-junction silicon solar cells, the doping type of the bottom silicon cell, and the corresponding so-called normal and inverted structure of the top perovskite cell, along with mechanical and monolithic tandemization schemes. In particular, we review and discuss the recent advances in manufacturing top perovskite cells using solution and vacuum deposition technology for large-area scalability and specific issues of recombination layers and top transparent electrodes for large-area PVK/Si tandem solar cells, which are indispensable for the final commercialization of tandem solar cells

Physical activity behaviour in people with diabetes residing in India: A cross-sectional analysis

Aim: To describe and analyse physical activity behaviour and barriers and facilitators, in adults with diabetes residing in India. Methods: The sample consisted of 190 (110 men and 80 women) adults with diabetes living in India. The mean age of the sample was 57 years (18 to 83 years), and the mean duration since diagnosis of diabetes was 10.38 years (SD 8.41 years). All participants completed a questionnaire about their physical activity behaviour, importance of, and barriers and facilitators. Results: 78.9% of participants thought that physical activity was important in the control of diabetes. 54.7% of respondents did regular physical activity every week, and physical activity was more frequent in men (63.6%), and in those with an intermediate (60%) or advanced (65.2%) level of English. Barriers that discouraged participants from physical activity were lack of time (31.6%), lack of knowledge (23.2%) and health limitations (17.4%). Potential identified facilitators included more information about physical activity (39%) and group exercise with people of the same sex or speaking the same language. Conclusions: Most of the sample thought that physical activity is important to control diabetes, although few participated in regular physical activity. Findings also suggest that physical activity had a higher importance for men, for those with an advanced level of English and those under 60 years of age. Men, those with intermediate or advance level of English, and people under 60 years were significantly more active

Prevalence and concentration of stx+ E. coli and E. coli O157 in bovine manure from Florida farms.

Fresh produce outbreaks due to Shiga toxin-producing Escherichia coli (STEC) continue to occur in the United States (US). Manure-amended soils can pose a public health risk when used for growing raw agricultural commodities. Knowing the prevalence and concentration of STEC in untreated biological soil amendments of animal origin (BSAAO) is important to help guide the most appropriate pre-harvest interval(s) following application to limit risks from these soil amendments. Bovine manure samples were collected from 12 farms in Florida, including samples from piles, lagoons, barns, and screened solids. Two methods were used to detect stx1/2 and rfbE genes in samples. A prevalence rate of 9% for stx1 and/or stx2 and 19% for rfbE was observed from the 518 bovine manure samples evaluated. A most probable number (MPN) assay was performed on stx+ samples when applicable. The geometric mean for stx+ samples (n = 20) was 3.37 MPN g-1 (0.53 log MPN g-1) with a maximum value of 6,800 MPN g-1 (3.83 log MPN g-1). This research was part of a larger nationwide geographical study on the prevalence and concentration of STEC in bovine manure to help guide regulations on feasible pre-harvest intervals for the application of untreated BSAAO

Photovoltaics: Nonhazardous Solvent Systems for Processing Perovskite Photovoltaics (Adv. Energy Mater. 14/2016)

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MPN g-¹ values for <i>stx</i>+ bovine manure samples with 95% confidence intervals.

MPN g-1 values for stx+ bovine manure samples with 95% confidence intervals.</p

Flow diagram of mEHEC and IMS-O157 methods.

The corresponding mEHEC reservoirs for stx+ samples were screened for stx to obtain an MPN g-1 value.</p

Percentage of <i>stx</i>, <i>stx1</i>, <i>stx2</i> and <i>rfbE</i>+ samples based on manure storage location.

Percentage of stx, stx1, stx2 and rfbE+ samples based on manure storage location.</p