This article explores the world of informal financial transactions and informal networks in pre-industrial France. Often considered merely as simple daily transactions made to palliate a lack of cash in circulation and to smooth consumption, the examination of private transactions reveals not only that they served various purposes, including productive investments, but also that they proved to be dynamic. The debts they incurred helped to smooth consumption but also helped to make investments. Some lenders were more prominent than others, although no one really dominated the informal market. This article also compares informal transactions with formal ones through the study of probate inventories and notarial records respectively. It compares these two credit circuits, their similarities and different characteristics, and their various networks features. The debts incurred in the notarial credit market were more substantial but did not serve a different purpose than in the informal market. Here too, the biggest lenders did not monopolise the extension of capital. Perhaps the most striking result lies in the fact that the total volume of exchange between the informal credit market and the notarial credit market (after projection) was similar.

The gas field ion source (GFIS) is able to generate tightly focused ion beams, which can be used to image or modify a specimen. Among the beam species, helium offers extremely high resolution, however, low sputter yield and sub-surface bubble formation are limiting factors in some applications. Therefore, heavier ions such as neon or nitrogen are used as well. In addition to being a suitable choice for lithographic mask editing, secondary electron (SE) generation by nitrogen beams has been recently shown to be affected by certain types of samples, providing additional contrast compared to helium ions. Here, we report our progress on the study of SE imaging differences between the nitrogen ion microscopy (N2IM) and helium ion microscopy (HIM). SE images of two nano-patterned samples comprising insulator, metal and carbon regions have been imaged by nitrogen and helium ions in two fundamentally different GFIS microscopes. The results corroborate previous reports of significant contrast differences in certain samples caused by the different ion species.

This paper focusses on the financial relations between the banking sector and the Treasury in Modern Spain. Tax systems have been insufficient, generating a chronic budget deficit. This drove to irresponsible public debt management, being the State a serial defaulter until 1987. This prevented the budget deficits could be financed by sovereign debt issued on the stock exchanges, and forced the state to resort to banks (public and private). The new series of public debt banks portfolios evolution is explained by their pursuit of returns and by changes in banking regulation and financial repression, which favoured the banking status quo. The paper analyses the causes of banking regulation, derived from the public borrowing policy and also from the banking lobbying strategy. It examines the consequences of the deadly banking-state embrace which brought about the interconnection between fiscal and banking crises.

Recent advances in historical national accounting have allowed for global comparisons of GDP per capita across space and time. Critics have argued that GDP per capita fails to capture adequately the multi-dimensional nature of welfare, and have developed alternative measures such as the human development index. Whilst recognising that these wider indicators provide an appropriate way of assessing levels of welfare, we argue that GDP per capita remains a more appropriate measure for assessing development potential, focussing on production possibilities and the sustainability of consumption. Twentieth-century Africa and pre-industrial Europe are used to show how such data can guide reciprocal comparisons to provide insights into the process of development on both continents.

Transistors with 600 V blocking capability and low switching losses are needed for converting one-phase 230 V mains voltage to lower voltage levels in switch-mode power supplies. The transistors operate as a switch and have to block the system voltage with minimized leakage currents in the OFF-state and have to conduct the current in the ON-state with minimized ON-state resistance. Additionally, any switching losses inside the transistor during the transitions in-between OFF and ON-states need to be minimized for efficient power-converting systems. Efficient high-voltage switching using gallium nitride (GaN)-based power transistors requires excellent material properties in the GaN/AlGaN epitaxial layers in conjunction with optimized process modules and device layout. In the example presented here, GaN buffer compositions and device geometry have been optimized to obtain very low vertical and lateral OFF-state leakage currents at 600 V drain bias and to enable a fast device turn-on with only a minor increase in dynamic ON-state resistance. The developed technology was applied to GaN layers grown on SiC and Si substrates to allow a direct comparison of both static and dynamic device parameters. By implementing a p-type GaN gate, normally OFF operation was realized for 70 mΩ/600 V transistors on both substrates. The new GaN-based devices outperform established Si-based superjunction metal oxide semiconductor field-effect transistors in terms of gate charge and switching energy.

This article reviews the development of SiC and GaN devices for power-switching applications in the context of four specifically identified application requirements: (1) high-blocking voltage, (2) high-power efficiency, (3) high-switching speed, and (4) normally OFF operation. Specific device and material characteristics, such as ON resistance, parasitic capacitances, and energy-gap values, are compared and discussed in relation to the identified application requirements. Following a review of the fundamental limitations of silicon as a material, this article describes the material advantages that motivated the development of commercially available Schottky diodes and transistors using SiC. The last section analyzes the potential of GaN to enable further technical progress beyond the theoretical limit of Si and to significantly reduce the cost of power-electronic switches.

Spin-polarized first-principles calculations have been conducted to study the electronic structures and magnetic properties of O and S functionalized zigzag aluminium nitride (AlN) nanoribbons. Chemical functionalization with O atoms at the edges strengthens the half-metallic properties of the AlN by adding new electronic states at the Fermi level for one spin-channel and widening the gap of the other. On the contrary, edge-termination with S atoms renders the AlN ribbon a semiconductor. Peierls instabilities towards the dimerization and trimerization of the doping atoms were observed.

The paper reports on the fabrication of electrical isolation for planar AlGaN/GaN high electron mobility transistor using Al double-implantation. The implantation was performed using Al+ ions with energies of 800 keV and 300 keV with doses of 1.5×1013 ion/cm2 and 1×1013 ion/cm2, respectively. Electrical measurements have shown that after implantation the sheet resistance was 1.8×1011 Ω/□ and increased to 1.17×1014 Ω/□ and 3.29×1012 Ω/□ after annealing at 400°C and 600°C respectively. Annealing at 800°C decreased the sheet resistance to 1.38×108 Ω/□. Characterization by XRD, Raman and photoluminescence spectroscopy give evidence that implantation damages the crystal lattice, yielding insulating properties. It has been demonstrated that the isolation is stable up to 600°C.

The development of safe, efficient, and economic hydrogen storage technologies is key for implementation of a hydrogen-based energy economy. In the search for high-hydrogen content materials, attention in the past decade has shifted to amides and borohydrides, two representative solid-state chemical sorption materials with high hydrogen capacities that had not been previously explored for hydrogen storage. A large number of new amide and borohydride systems have recently been developed that expand the material scope for hydrogen storage. This article reviews the current progress in amides and borohydrides with emphases on material design and kinetic improvement.

Until 2008, Ireland's banks had a solid reputation. Its two long-established banks could trace their origins back to the beginnings of joint-stock banking in 1825. Few banks of consequence had failed in the interim. The last such failure, the focus of this article, was that of the Munster Bank in 1885. That event tells us much about the history of Irish banking before recent events.

Electronic structure calculations using the Heyd-Scuseria-Ernzerhof (HSE) hybrid functional are presented for NO-pair complexes with and without hydrogen to test the hypothesis that such defect complexes could lead to shallower levels than for isolated NO and hence p-type doping. The H is found to bind strongly to one of the N in the pair and removes thecorresponding defect level from the gap but the second N’s polaronic defect level in the gap remains deep.

In this paper, we compare degradation modes and failure mechanisms of different AlGaN/GaN HEMT technologies. We present data concerning reverse-bias degradation of GaN-based HEMTs, which results in a dramatic increase of gate leakage current, and present a timedependent model for gate degradation. Some of the tested technologies demonstrated to be immune from this failure mechanism up to drain-gate voltages in excess of 100 V. When this was the case, the main failure mode consisted of drain current degradation during on-state tests, resulting from charge trapping in the gate-drain access region attributed to hot-electron effects. Finally, the use of diagnostic techniques such as electroluminescence microscopy and Deep Level Transient Spectroscopy for the identification of failure modes and mechanisms of GaNbased HEMTs is reviewed. Concerning reverse-bias degradation of GaN-based HEMTs, we demonstrate that, (i) when submitted to reverse-gate stress, HEMTs can show both recoverable and permanent degradation. (ii) recoverable degradation consists of a decrease in gate current and threshold voltage, which are ascribed to the simultaneous trapping of negative charge in the AlGaN layer, and of positive charge close to the AlGaN/GaN interface. (iii) permanent degradation is manifested by the generation of parasitic leakage paths. Time-dependent analysis suggests that permanent degradation can be ascribed to a defect generation and percolation process. Results supports the existence of a time to breakdown for HEMT degradation, which significantly depends on the stress voltage level. On the contrary, AlGaN/GaN technologies which were found to be resistant to gate degradation (off-state critical voltage larger than 100 V for a 0.25 um gate device) were subjected to on-state tests at different gate and drain voltage levels. All tests showed a non-recoverable degradation of electrical parameters (drain saturation current, threshold voltage and on-state resistance) and electroluminescence signal EL, with a strong dependence on the EL value of the bias point, and a negligible dependence of temperature. Once verified that EL intensity represents a reliable estimate of channel hot electron effects, we attributed the degradation to hot electron trapping in the gate-drain access region. Using EL intensity as a measure of the stress acceleration factor, we derived an acceleration law for GaN HEMT hot electron degradation similar to the one already demonstrated for GaAs devices.

Zinc oxide (ZnO) is a semiconductor that emits bright UV light, with little wasted heat. This intrinsic feature makes it a promising material for energy-efficient white lighting, nano-lasers, and other optical applications. For devices to be competitive, however, it is necessary to develop reliable p-type doping. Although substitutional nitrogen has been considered as a potential p-type dopant for ZnO, recent theoretical and experimental work suggests that nitrogen is a deep acceptor and will not lead to p-type conductivity. In nitrogen-doped samples, a red photoluminescence (PL) band is correlated with the presence of deep nitrogen acceptors. PL excitation (PLE) measurements show an absorption threshold of 2.26 eV, in good agreement with theory. The results of these studies seem to rule out group-V elements as shallow acceptors in ZnO, contradicting numerous reports in the literature. Optical studies on ZnO nanocrystals show some intriguing leads. At liquid-helium temperatures, a series of sharp IR absorption peaks arise from an unknown acceptor impurity. The data are consistent with a hydrogenic acceptor 0.46 eV above the valence band edge. While this binding energy is still too deep for many practical applications, it represents a significant improvement over the 1.4-1.5 eV binding energy for nitrogen acceptors. Nanocrystals present another twist. Due to their high surface-to-volume ratio, surface states are especially important. In our model, the 0.46 eV level is shallow with respect to the surface valence band, raising the possibility of surface hole conduction.

Modified embedded-atom method (MEAM) interatomic potentials for Nb-C, Nb-N, Fe-Nb-C, and Fe-Nb-N systems have been developed based on the previously developed MEAM potentials for lower order systems. The potentials reproduce various fundamental physical properties (structural properties, elastic properties, thermal properties, and surface properties) of NbC and NbN, and interfacial energy between bcc Fe and NbC or NbN, in generally good agreement with higher-level calculations or experimental information. The applicability of the present potentials to atomic-level investigations to the precipitation behavior of complex-carbonitrides (Nb,Ti)(C,N) as well as NbC and NbN, and their effects on the mechanical properties of steels are also discussed.

We report on a direct comparison of the effect of the atmospheric contaminants on a-Si:H and μc-Si:H p-i-n solar cells deposited by plasma-enhanced chemical vapor deposition (PECVD) at 13.56 MHz. Nitrogen and oxygen were inserted by two types of controllable contamination sources: (i) directly into the plasma through a leak at the deposition chamber wall or (ii) into the process gas supply line. Similar critical concentrations in the range of 4-6×1018 cm-3 for nitrogen and 1.2-5×1019 cm-3 for oxygen were observed for both a-Si:H and μc-Si:H cells for the chamber wall leak. Above these critical concentrations the solar cell efficiency decreases for a-Si:H solar cells due to losses in the fill factor under red light illumination (FFred). For μc-Si:H cells the losses in FFred and in short-circuit current density deteriorate the device performance. Only for a-Si:H the critical oxygen concentration is found to depend on the contamination source. Conductivity measurements suggest that at the critical oxygen concentration the Fermi level is located about 0.05 eV above midgap for both a-Si:H and μc-Si:H.

This study compares p-MOS capacitors fabricated on N+ implanted and on virgin 4H-SiC. The former sample have N at the SiO2/SiC interface, the latter have not. To investigate the presence of deep and shallow hole traps at the SiO2/SiC interface, high frequency and quasi-static capacitance voltage measurements under dark have been compared for bias sweeping from accumulation to depletion and from depletion to accumulation, the latter after white light illumination. The presence of N has an effect on the density of the shallow donor like traps but none effect on the deep ones. The positive charge trapped in the oxide and/or at the oxide interface after equivalent tunneling hole injection have been compared and are equivalent. Time dependent dielectric breakdown tests have been compared too. The oxide grown on N+implanted SiC broken at lower electric field.

The N-doped ZnO was prepared by heating a mixture of zinc nitrate hexahydrate [Zn(NO3)2·6 H2O] and ammonium salt at 623 K for 1 h in air. The mixture of zinc nitrate hydrate and ammonium salt formed a homogeneous molten salt at 623 K, and the homogeneous dispersion of the metal ions and ammonium ions contributed to the N-doping. In particular, when the mixture of zinc nitrate hydrate and ammonium acetate (CH3COONH4) was heated at 623 K, the doped amount of nitrogen was higher than with the mixture of zinc nitrate hydrate and NH4NO4. The acetate anion (CH3COO−) restricted the oxidation reaction of nitrate anion (NO3−). Furthermore, Al- and N-co-doped ZnO particles were obtained by heating the mixture of zinc nitrate hydrate, aluminum nitrate hydrate, and ammonium acetate. The Al and N co-doping effectively increased the doped amount of nitrogen. The spontaneous formation of ZnO lattice and the nitrogen source in the molten salt and the homogeneous dispersion of Zn2+ ions and Al3+ ions contributed to the increase in the amount of doped nitrogen.

Nitrogen and tellurium co-doped ZnO (ZnO:[N+Te]) films have been grown on (0001) ZnO substrate by plasma-assisted molecular beam epitaxy. The electron concentration of tellurium doped ZnO (ZnO:Te) gradually increases, compared that of undoped ZnO (u-ZnO). On the other hand, conductivity of ZnO:[N+Te] changes from n-type to p-type characteristic with a hole concentration of 4×1016 cm-3. However, nitrogen doped ZnO film (ZnO:N) still remain as n-type conductivity with a electron concentration of 2.5×1017 cm-3. Secondary ion mass spectroscopy reveals that nitrogen concentration ([N]) of ZnO:[N+Te] film (2×1021 cm-3) is relatively higher than that of ZnO:N film (3×1020 cm-3). 10 K photoluminescence spectra shows that considerable improvement of emission properties of ZnO:[N+Te] with an emergence of narrow acceptor bound exciton (A°X, 3.359 eV) and donor-acceptor pair (DAP, 3.217 eV), compared with those of u-ZnO. Consequently, high quality p-type ZnO with high N concentration is realized by using Te and N co-doping technique due to reduction of Madelung energy.

The incorporation of small amounts of N into III-V antimonide-containing semiconductor alloys allows a drastic expansion of available wavelengths for infrared (IR) detector applications. Quaternary films containing three group-V elements can be lattice matched to the most prevalent substrates for IR applications, such as InAs, GaAs, and GaSb. It is not trivial to incorporate N while maintaining the high crystalline quality required for IR devices. Current materials characterization studies of dilute-nitride films consisting of more than two group-V elements has yielded conflicting information related to their competing behavior and the extent of N incorporation. Due to challenges related to light-element microanalysis for many characterization techniques, and the small concentrations of N involved, it is difficult to quantify the amount of N incorporated into dilute-nitride films. In this study, we use transmission electron microscopy (TEM), energy-dispersive spectroscopy (EDS), and x-ray diffraction (XRD) to study the incorporation behaviors of the competing group-V elements in InAsSbN films.