8 research outputs found
Interface Modification for Energy Levels Alignment and Charge Extraction in CsPbI Perovskite Solar Cells
In perovskite solar cells (PSCs) energy levels alignment and charge
extraction at the interfaces are the essential factors directly affecting the
device performance. In this work, we present a modified interface between
all-inorganic CsPbI perovskite and its hole selective contact
(Spiro-OMeTAD), realized by a dipole molecule trioctylphosphine oxide (TOPO),
to align the energy levels. On a passivated perovskite film, by n-Octyl
ammonium Iodide (OAI), we created an upward surface band-bending at the
interface by TOPO treatment. This improved interface by the dipole molecule
induces a better energy level alignment and enhances the charge extraction of
holes from the perovskite layer to the hole transport material. Consequently, a
Voc of 1.2 V and high-power conversion efficiency (PCE) of over 19% were
achieved for inorganic CsPbI perovskite solar cells. Further, to
demonstrate the effect of the TOPO dipole molecule, we present a layer-by-layer
charge extraction study by transient surface photovoltage technique (trSPV)
accomplished by charge transport simulation.Comment: 20 pages, 4 Figure
Association of kidney disease measures with risk of renal function worsening in patients with type 1 diabetes
Background: Albuminuria has been classically considered a marker of kidney damage progression in diabetic patients and it is routinely assessed to monitor kidney function. However, the role of a mild GFR reduction on the development of stage 653 CKD has been less explored in type 1 diabetes mellitus (T1DM) patients. Aim of the present study was to evaluate the prognostic role of kidney disease measures, namely albuminuria and reduced GFR, on the development of stage 653 CKD in a large cohort of patients affected by T1DM. Methods: A total of 4284 patients affected by T1DM followed-up at 76 diabetes centers participating to the Italian Association of Clinical Diabetologists (Associazione Medici Diabetologi, AMD) initiative constitutes the study population. Urinary albumin excretion (ACR) and estimated GFR (eGFR) were retrieved and analyzed. The incidence of stage 653 CKD (eGFR < 60 mL/min/1.73 m2) or eGFR reduction > 30% from baseline was evaluated. Results: The mean estimated GFR was 98 \ub1 17 mL/min/1.73m2 and the proportion of patients with albuminuria was 15.3% (n = 654) at baseline. About 8% (n = 337) of patients developed one of the two renal endpoints during the 4-year follow-up period. Age, albuminuria (micro or macro) and baseline eGFR < 90 ml/min/m2 were independent risk factors for stage 653 CKD and renal function worsening. When compared to patients with eGFR > 90 ml/min/1.73m2 and normoalbuminuria, those with albuminuria at baseline had a 1.69 greater risk of reaching stage 3 CKD, while patients with mild eGFR reduction (i.e. eGFR between 90 and 60 mL/min/1.73 m2) show a 3.81 greater risk that rose to 8.24 for those patients with albuminuria and mild eGFR reduction at baseline. Conclusions: Albuminuria and eGFR reduction represent independent risk factors for incident stage 653 CKD in T1DM patients. The simultaneous occurrence of reduced eGFR and albuminuria have a synergistic effect on renal function worsening
Measurement of the W-boson mass in pp collisions at √s=7 TeV with the ATLAS detector
A measurement of the mass of the W boson is presented based on proton–proton collision data recorded in 2011 at a centre-of-mass energy of 7 TeV with the ATLAS detector at the LHC, and corresponding to 4.6 fb−1 of integrated luminosity. The selected data sample consists of 7.8×106 candidates in the W→μν channel and 5.9×106 candidates in the W→eν channel. The W-boson mass is obtained from template fits to the reconstructed distributions of the charged lepton transverse momentum and of the W boson transverse mass in the electron and muon decay channels, yielding
mW=80370±7 (stat.)±11(exp. syst.)
±14(mod. syst.) MeV
=80370±19MeV,
where the first uncertainty is statistical, the second corresponds to the experimental systematic uncertainty, and the third to the physics-modelling systematic uncertainty. A measurement of the mass difference between the W+ and W−bosons yields mW+−mW−=−29±28 MeV
Monolithic Perovskite/Silicon-Heterojunction Tandem Solar Cells with Nanocrystalline Si/SiOx Tunnel Junction
Perovskite/silicon tandem solar cells have strong potential for high efficiency and low cost photovoltaics. In monolithic (two-terminal) configurations, one key element is the interconnection region of the two subcells, which should be designed for optimal light management and prevention of parasitic p/n junctions. We investigated monolithic perovskite/silicon-heterojunction (SHJ) tandem solar cells with a p/n nanocrystalline silicon/silicon-oxide recombination junction for improved infrared light management. This design can additionally provide for resilience to shunts and simplified cell processing. We probed modified SHJ solar cells, made from double-side polished n-type Si wafers, which included the proposed front-side p/n tunnel junction with the p-type film simultaneously functioning as selective charge transport layer for the SHJ bottom cell, trying different thicknesses for the n-type layer. Full tandem devices were then tested, by applying a planar n-i-p mixed-cation mixed-halide perovskite top cell, fabricated via low temperature solution methods to be compatible with the processed Si wafer. We demonstrate the feasibility of this tandem cell configuration over a 1 cm2 area with negligible J-V hysteresis and a VOC ~1.8 V, matching the sum of the VOC-s contributed by the two components
Interface Modification for Energy Level Alignment and Charge Extraction in CsPbI<sub>3</sub> Perovskite Solar Cells
In perovskite solar
cells (PSCs) energy level alignment and charge
extraction at the interfaces are the essential factors directly affecting
the device performance. In this work, we present a modified interface
between all-inorganic CsPbI3 perovskite and its hole-selective
contact (spiro-OMeTAD), realized by the dipole molecule trioctylphosphine
oxide (TOPO), to align the energy levels. On a passivated perovskite
film, with n-octylammonium iodide (OAI), we created
an upward surface band-bending at the interface by TOPO treatment.
This improved interface by the dipole molecule induces a better energy
level alignment and enhances the charge extraction of holes from the
perovskite layer to the hole transport material. Consequently, a Voc of 1.2 V and a high-power conversion efficiency
(PCE) of over 19% were achieved for inorganic CsPbI3 perovskite
solar cells. Further, to demonstrate the effect of the TOPO dipole
molecule, we present a layer-by-layer charge extraction study by a
transient surface photovoltage (trSPV) technique accomplished by a
charge transport simulation