Photovoltaic efficiencies of microwave and Cu2ZnSnS4 (CZTS) superstrate solar cells

Organic and inorganic materials such as perovskites, copper indium gallium diselenide, cadmium telluride, and copper zinc tin sulfide/selenide (CZTS/Se) have been employed to capture unlimited sunlight through the photovoltaic effect. CZTS/Se is regarded as the most promising, most environmentally friendly, most abundant candidate with high absorption coefficient and tunable bandgap for the generation of solar energy. Superstrate architectures have numerous advantages over the substrate architectures and for this reason; it offers a promising route for producing solar cells at a relatively low cost. This article reviews the state-of-the-art knowledge on the synthesis, crystal structure, electronic properties, defects, and secondary phases of CZTS. The CZTS solar cell device architecture and mechanism of the substrate and superstrate configurations were also covered in the review. The preparation of superstrate CZTS via vacuum and non-vacuum methods, as well as their photovoltaic efficiencies were critically discussed. The microwave synthesis and characterization of CZTS nanoparticles were also reviewed with respect to the effect of temperature, surfactant, and reagents on the physical properties of the nanomaterials. The application of microwave-synthesized CZTS nanoparticles in the advancement of thin film solar cells was also critically examined. Finally, the challenges and the prospects of CZTS solar cells were also presente

Few Losses to Follow-up in a Sub-Saharan African Cancer Cohort via Active Mobile Health Follow-up

Accurate survival estimates are needed for guiding cancer control efforts in sub-Saharan Africa, but previous studies have been hampered by unknown biases due to excessive loss to follow-up (LTFU). In the African Breast Cancer-Disparities in Outcomes Study, a prospective breast cancer cohort study, we implemented active mobile health follow-up, telephoning each woman or her next-of-kin (NOK) trimonthly on her mobile phone to update information on her vital status. Dates of every contact with women/NOK were analyzed from diagnosis in 2014-2017 to the earliest of September 1, 2018, death, or 3 years postdiagnosis. The cumulative incidence of being LTFU was calculated considering deaths as competing events. In all, 1,490 women were followed for a median of 24.2 (interquartile range (IQR), 14.2-34.5) months, corresponding to 8,529 successful contacts (77% of total contacts) with the women/NOK. Median time between successful contacts was 3.0 (IQR, 3.0-3.7) months. In all, 71 women (5.3%) were LTFU at 3 years: 0.8% in Nigeria, 2.2% in Namibia, and 5.6% in Uganda. Because of temporary discontinuity of active follow-up, 20.3% of women were LTFU after 2 years in Zambia. The median time to study notification of a death was 9.1 (IQR, 3.9-14.0) weeks. Although the present study was not a randomized controlled trial, in this cancer cohort with active mobile health follow-up, LTFU was much lower than in previous studies and enabled estimation of up-to-date and reliable cancer survival

Adverse effect profile of patients on community treatment for Drug Resistant Tuberculosis (DRTB) in Abia State, Nigeria

No Abstract