Displacement Damage dose and DLTS Analyses on Triple and Single Junction solar cells irradiated with electrons and protons

Space solar cells radiation hardness is of fundamental importance in view of the future missions towards harsh radiation environment (like e.g. missions to Jupiter) and for the new spacecraft using electrical propulsion. In this paper we report the radiation data for triple junction (TJ) solar cells and related component cells. Triple junction solar cells, InGaP top cells and GaAs middle cells degrade after electron radiation as expected. With proton irradiation, a high spread in the remaining factors was observed, especially for the TJ and bottom cells. Very surprising was the germanium bottom junction that showed very high degradation after protons whereas it is quite stable against electrons. Radiation results have been analyzed by means of the Displacement Damage Dose method and DLTS spectroscopy.Comment: Abstract accepted for poster session at 2017 IEEE Nuclear and Space Radiation Effects Conference, July 17-21, New Orlean

31% European InGaP/GaAs/InGaAs Solar Cells for Space Application

We report a triple junction InGaP/GaAs/InGaNAs solar cell with efficiency of ~31% at AM0, 25 °C fabricated using a combined molecular beam epitaxy (MBE) and metal-organic chemical vapour deposition (MOCVD) processes. The prototype cells comprise of InGaNAs (Indium Gallium Nitride Arsenide) bottom junction grown on a GaAs (Gallium Arsenide) substrate by MBE and middle and top junctions deposited by MOCVD. Repeatable cell characteristics and uniform efficiency pattern over 4-inch wafers were obtained. Combining the advantages offered by MBE and MOCVD opens a new perspective for fabrication of high-efficiency space tandem solar cells with three or more junctions. Results of radiation resistance of the sub-cells are also presented and critically evaluated to achieve high efficiency in EOL conditions

31% European InGaP/GaAs/InGaAs Solar Cells for Space Application

We report a triple junction InGaP/GaAs/InGaNAs solar cell with efficiency of ~31% at AM0, 25 °C fabricated using a combined molecular beam epitaxy (MBE) and metal-organic chemical vapour deposition (MOCVD) processes. The prototype cells comprise of InGaNAs (Indium Gallium Nitride Arsenide) bottom junction grown on a GaAs (Gallium Arsenide) substrate by MBE and middle and top junctions deposited by MOCVD. Repeatable cell characteristics and uniform efficiency pattern over 4-inch wafers were obtained. Combining the advantages offered by MBE and MOCVD opens a new perspective for fabrication of high-efficiency space tandem solar cells with three or more junctions. Results of radiation resistance of the sub-cells are also presented and critically evaluated to achieve high efficiency in EOL conditions

31% European InGaP/GaAs/InGaAs Solar Cells for Space Application

We report a triple junction InGaP/GaAs/InGaNAs solar cell with efficiency of ~31% at AM0, 25 °C fabricated using a combined molecular beam epitaxy (MBE) and metal-organic chemical vapour deposition (MOCVD) processes. The prototype cells comprise of InGaNAs (Indium Gallium Nitride Arsenide) bottom junction grown on a GaAs (Gallium Arsenide) substrate by MBE and middle and top junctions deposited by MOCVD. Repeatable cell characteristics and uniform efficiency pattern over 4-inch wafers were obtained. Combining the advantages offered by MBE and MOCVD opens a new perspective for fabrication of high-efficiency space tandem solar cells with three or more junctions. Results of radiation resistance of the sub-cells are also presented and critically evaluated to achieve high efficiency in EOL conditions

Coronary flow, VO2 peak and anaerobic threshold in patients with dilated cardiomyopathy.

Background: Coronary flow is influenced by several determinants and may change according to external stimuli. In patients with dilated cardiomyopathy (DC), adaptive mechanisms could induce alterations in coronary flow, possibly related to oxygen consumption. Methods: In 67 consecutive patients with DC (mean age 52.06T13.84, 52 male gender, left ventricle ejection fraction (LVEF) 29.49%T8.68) and normal coronary angiography findings, coronary flow in left anterior descending (LAD), right coronary artery (RC) and left circumflex (LCx) was reported as TIMI frame count (TFC). All patients underwent a cardiopulmonary test with VO2 peak and anaerobic threshold (AT) measurement, New York Heart Association (NYHA) class stratification, two-dimensional echocardiographic evaluation including LVEF and left ventricle end-diastolic diameter (LVEDD) assessment. All patients were receiving optimal medical treatment. Results: In a multivariate analysis, a statistically significant correlation was found between VO2 peak and TFC (B 7.61, p <0.001, R2 0.61 for LAD; B 3.42, p <0.001, R2 0.33 for RC); an inverse correlation was found between AT and TFC (B 9.77, p <0.001, R2 0.61 for LAD; B 4.26, p <0.001, R2 0.33 for RC). Conclusions: Coronary flow is related to VO2 peak and AT in patients with DC, suggesting a ‘‘compensatory’’ mechanism