Data on dopant characteristics and band alignment of CdTe cells with and without a ZnO highly-resistive-transparent buffer layer

Photovoltaic enhancement of cadmium telluride (CdTe) thin film solar cells using a 50 nm thick, atomic-layer-deposited zinc oxide (ZnO) buffer film was reported in “Enhancement of the photocurrent and efficiency of CdTe solar cells suppressing the front contact reflection using a highly-resistive ZnO buffer layer” (Kartopu et al., 2019) [1].Data presented here are the dopant profiles of two solar cells prepared side-by-side, one with and one without the ZnO highly resistive transparent (HRT) buffer, which displayed an open-circuit potential (Voc) difference of 25 mV (in favor of the no-buffer device), as well as their simulated device data. The concentration of absorber dopant atoms (arsenic) was measured using the secondary ion mass spectroscopy (SIMS) method, while the density of active dopants was calculated from the capacitance-voltage (CV) measurements. The solar cell simulation data was obtained using the SCAPS software, a one-dimensional solar cell simulation programme. The presented data indicates a small loss (around 20 mV) of Voc for the HRT buffered cells

Enhancement of the photocurrent and efficiency of CdTe solar cells suppressing the front contact reflection using a highly-resistive ZnO buffer layer

We report on the effects of using an atomic layer deposited ZnO transparent buffer layer with > 106 Ω cm resistivity on the performance of CdZnS/CdTe solar cells grown by metalorganic chemical vapour deposition (MOCVD). The buffer film thickness is adjusted by optical modelling to suppress the reflection losses at the front contact. A clear improvement, up to 1.8% in conversion efficiency, was obtained in comparison to reference devices without the ZnO buffer layer, thanks to the enhancement of the current density (Jsc) and fill factor (FF). Device spectral response showed improved collection for most of the visible region. Reflectance measurements confirmed that the ZnO film reduced the optical reflectance around the transparent front contact. This effect permitted light management through the front contact leading to an improvement of the Jsc and hence the photovoltaic conversion efficiency. These results are intriguing since the literature on CdTe solar cells did not previously report improvement to the photocurrent and device response through controlling the highly-resistive transparent buffer layer

Plasma assisted atomic layer deposition of nickel oxide as hole transport layer for hybrid perovskite solar cells

Low-temperature atomic layer deposition (ALD) offers significant merits in terms of processing uniform, conformal and pinhole-free thin films, with sub-nanometer thickness control. In this work, plasma-assisted atomic layer deposition (ALD) of nickel oxide (NiO) is carried out by adopting bis-methylcyclopentadienyl-nickel (Ni(MeCp)2) as precursor and O2 plasma as co-reactant, over a wide table temperature range of 50-300 °C. A growth rate of 0.32 Å per cycle is obtained for films deposited at 150 °C with an excellent thickness uniformity on a 4 inch silicon wafer. Bulk characteristics of the NiO film together with its interfacial properties with a triple cation hybrid perovskite absorber layer are comprehensively investigated, with the aim of integrating NiO as hole transport layer (HTL) in a p-i-n perovskite solar cell (PSC) architecture. It is concluded that “key” to efficient solar cell performance is the post-annealing treatment of the ALD NiO films in air, prior to perovskite synthesis. Post-annealing leads to better wettability of the perovskite layer and increased conductivity and mobility of the NiO films, delivering an increase in short-circuit current density (Jsc) and fill factor (FF) in the fabricated devices. Overall, a superior 17.07% PCE is achieved in the post-annealed NiO-based PSC when compared to the 13.98% PCE derived from the one with pristine Ni

Project Brainstorm: Using Neuroscience to Connect College Students with Local Schools

Neuroscience can be used as a tool to inspire an interest in science in school children as well as to provide teaching experience to college students

The AGILE Mission

AGILE is an Italian Space Agency mission dedicated to observing the gamma-ray Universe. The AGILE's very innovative instrumentation for the first time combines a gamma-ray imager (sensitive in the energy range 30 MeV-50 GeV), a hard X-ray imager (sensitive in the range 18-60 keV), a calorimeter (sensitive in the range 350 keV-100 MeV), and an anticoincidence system. AGILE was successfully launched on 2007 April 23 from the Indian base of Sriharikota and was inserted in an equatorial orbit with very low particle background. Aims. AGILE provides crucial data for the study of active galactic nuclei, gamma-ray bursts, pulsars, unidentified gamma-ray sources, galactic compact objects, supernova remnants, TeV sources, and fundamental physics by microsecond timing. Methods. An optimal sky angular positioning (reaching 0.1 degrees in gamma- rays and 1-2 arcmin in hard X-rays) and very large fields of view (2.5 sr and 1 sr, respectively) are obtained by the use of Silicon detectors integrated in a very compact instrument. Results. AGILE surveyed the gamma- ray sky and detected many Galactic and extragalactic sources during the first months of observations. Particular emphasis is given to multifrequency observation programs of extragalactic and galactic objects. Conclusions. AGILE is a successful high-energy gamma-ray mission that reached its nominal scientific performance. The AGILE Cycle-1 pointing program started on 2007 December 1, and is open to the international community through a Guest Observer Program

Study of the effect of lamination process on pasta by physical chemical determination and near infrared spectroscopy analysis

The objective of this study was to evaluate the chemical and physical characteristics of fresh egg pasta samples obtained by using two different production methodologies: extrusion and lamination. The results of the study demonstrate that products have different characteristics in terms of colour and level of gelatinization, while they do not show significant differences with regard to the amount of absorbed water during the cooking stage. It was evaluated that it is possible to discriminate the two kinds of products by using FT-NIR spectroscopy. FT-NIR analysis results suggest the presence of a different matrix\u2013water association, a diverse level of starch gelatinization and a distinct starch\u2013gluten interaction in the two kinds of pasteurised samples