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The GaAsN alloy has a great potential in the manufacture of the photovoltaic devices. A simple optimized GaAsN junction can reach conversion efficiency from > 20%, comparable with that reached by the best cells of die CISGS. Because the band gap of GaAsN can be modified from 1.4 eV to 3.4 eV by increasing the nitrogen content with multi-junction cells, it is theoretically possible to achieve the record performance 70% with this only material system, whereas the theoretical record in technology GaAs multi-junctions is less than 50%. The work presented in this paper concerns the study of photovoltaic cells based on GaAsN nitrided materials. The main objective is to optimize the front and base with their thickness and doping, on the electrical characteristic of the photovoltaic cell and subsequently its output parameters under solar illumination of AM1.5G. 54.1 % efficiency is predicted for this new GaAs1-xNx based on a simple single solar cell. This structure can also provide a fundamental solar cell unit for developing very high efficiency IBSC solar cell.

The ternary (ABX2) semiconductors have wide optical band gaps range and motilities of carrier, has led to their appearance importance device materials, including solar cells of photovoltaic and lig...

Dilute nitride semiconductors, such as GaAs1–xNx alloys, have attracted considerable attention due to their unique physical properties and wide range of their possible application in optoelectronic...

In this paper, the high efficiency Cu(In,Ga)Se2 (CIGS)-based solar cells solar cells was analyzed and designed by SCAPS-1D software. This paper deals with the influence of a buffer layer on the performance of the CIGS-based solar cells. The photovoltaic parameters have been calculated in different buffer layer materials (CdS, ZnS, ZnSe), we give great alternative for Cadmium sulphide (CdS). Starting with a good structure, we simulated the J-V characteristics and showed how the absorber and buffer layers thickness, defect density influence the short-circuit current density (Jsc), open-circuit voltage (Vco), fill factor (FF), and efficiency (η) of solar cell. The optimized solar cell shows an efficiency of > 22% under the AM1.5G spectrum and one sun.

The current-voltage (I-V) characteristics of Pt/(n.u.d)-GaN and Pt/Si-doped-GaN diodes Schottky are investigated. Based on these measurements, physical mechanisms responsible for electrical conduction have been suggested. The contribution of thermionic-emission current and various other current transport mechanisms were assumed when evaluating the Schottky barrier height. Thus the generation-recombination, tunneling and leakage currents caused by inhomogeneities and defects at metal-semiconductor interface were taken into account.

In this study, the forward bias current-voltage-temperature (I-V-T) characteristics of (Mo/Au)–AlGaN/GaN high electron mobility transistors (HEMTs) have been investigated over the temperature range of 100-450K. The barrier height (Fb), ideality factor (n), series resistance (Rs) and shunt resistance (Rp) of (Mo/Au)–AlGaN/GaN HEMTs have been calculated from their experimental forward bias current–voltage-temperature (I-V-T). The capacitance–voltage (C–V) of (Au/Mo)- AlGaN/GaN HEMTs were investigated at room temperature. The doping concentration (Nd) and the bi- dimensional sheet carrier density (ns) were evaluated from C–V data. The experimental results show that all forward bias semilogarithmic I-V curves for the different temperatures have a nearly common cross point at a certain bias voltage, even with finite series resistance (Rs). We found that the value of Fb and Rs increases by cons n and Rp decreases with increasing temperature. The values of Nss obtained by taking into account the Rs are about one order lower than those obtained without considering the Rs.

In this paper, we have studied the Schottky contact of Ni/Au/AlInN/GaN HEMTs. The current–voltage Igs (Vgs) of Ni/Au/AlInN/GaN structures were investigated at room temperature. The electrical parameters such as ideality factor (2.3), barrier height (0.72 eV) and series resistance (33 W) were evaluated from I(V) data, the threshold voltage (-2.42 V), the 2D gas density (1.35 ´ 1013 cm-2) and barrier height (0.94 eV) were evaluated from C(V) data.

In this work, electrical characterization of the current-voltage and capacitance- voltage curves for the Metal/InN/InP Schottky structures are investigated. We have studied electrically thin InN films realized by the nitridation of InP (100) substrates using a Glow Discharge Source (GDS) in ultra high vacuum. The I (V) curves have exhibited anomalous two-step (kink) forward bias behaviour; a suitable fit was only obtained by using a model of two discrete diodes in parallel. Thus, we have calculated, using I(V) and C(V) curves of Hg/InN/InP Schottky structures, the ideality factor n, the saturation current Is, the barrier height jB, the series resistance Rs, the doping concentration Nd and the diffusion voltage Vd. We have also presented the band diagram of this heterojunction which indicates the presence of a channel formed by holes at the interface InN/InP which explain by the presence of two-dimensional electron gas (2-DEG) and this was noticed in the presentation of characteristics C(V).

Copper indium gallium diselenide (CuIn1-xGaxSe2 or CIGSe) solar cells has been considered to be one of the most promising thin-film solar cells and is important for terrestrial applications because of their high efficiency, long-term stable performance and potential for low-cost production. In this work, the CIGS heterojunction solar cell has been numerically simulated using SCAPS-1D tool. We study the influence of a buffer layer on the performance of the CIGSe solar cells. Quantum (...)

In this paper, we have studied the Schottky contact of two structures AlInN/GaN and AlGaN/GaN in transistors HEMTs. The current–voltage Igs(Vgs) of AlInN/GaN and AlGaN/GaN structures were investigated at room temperature. The electrical parameters such as ideality factor (2.3 and 1.96), barrier height (0.72 and 0.71 eV) and series resistance (33 and 153 $$\Omega $$ ) were evaluated from I–V data. The comparison of the performance of the two structures AlInN/GaN and AlGaN/GaN in transistors HEMTs have been analyzed and discussed.

In this paper, we developed a numerical calculation program, using Turbo Pascal, to determine the current–voltage characteristics of a $$\hbox {N}^{+}\hbox {P}$$ solar cells in order to find the main parameters influencing the conversion efficiency. We adopted a one-dimensional numerical model for the resolution of the three semiconductor equations, which are: the Poisson’s equation and the two continuity equations of electrons and holes. Our system of equations is written in term of $$\varphi ,\, \varphi _{n}$$ , and $$\varphi _{p}$$ , and it’s resolved using the finite difference method. This code enables us to draw the current density versus the voltage for different layer thicknesses, the conversion efficiency versus the minority carrier life time and the spectral response versus the wavelength. In order to compare the conversion efficiency of two different solar cells, we simulated a solar cell based on III–V nitride compounds $$(\hbox {In}_\mathrm{x}\hbox {Ga}_{1-\mathrm{x}}\hbox {N})$$ and a monocrystalline silicon solar cell.

The current–voltage ( I – V ) and capacitance–voltage ( C – V ) characteristics of Al/n-GaAs and Al/p-GaAs diodes on GaAs substrate treated by Ru 3+ ions are investigated and compared with characteristics of GaAs diodes on GaAs untreated substrates. The diodes does not have to show an ideal behaviour of I – V characteristic with an ideality factor of 1.13 and barrier height of 0.85 eV and 0.6 eV for Al/n-GaAs and Al/p-GaAs diodes respectively. The forward bias saturation current found with a big value (10 −10 A, 10 −12 A) in the Al/n-GaAs (untreated) Schottky diodes compared with Al/n-GaAs (treated) diodes. Contrary the forward bias saturation current found with a small value (10 −7 A, 10 −6 A) in the Al/p-GaAs (untreated) Schottky diodes compared with Al/p-GaAs (treated) diodes. The energy distribution of interface states was determined from the forward bias I (V) characteristics. The interface states density found large in the Al/GaAs (treated by Ru 3+ ions) structure comparing with the Al/GaAs (untreated) structure. In parallel with electrical measurement, the Ru 3+ adsorption on treated GaAs surfaces was controlled by photoelectrochemical and electrochemical measurements and by Auger analysis.

In addition to better electronic properties than silicon, gallium arsenide exhibits interesting optical properties. It is possible to realize the integration of both electronic and optical functions on the same GaAs wafer. However, its interfacial properties limit the use of GaAs for electronic devices (MIS, MESFET, etc.) [Electron. Technol. 27 (2) (1994) 69; J. Electron. Mater. 31 (1) (2002) 71]. Heller [U.S. Patent 4 (1981) 213] has proposed chemical treatments of GaAs surface by selenide and ruthenium solutions that induce an increase in electrochemical photocell yield. Two alternative explanations have been proposed to account for this effect: the first is by Heller [Acc. Chem. Res. 14 (1981) 154] who has assumed a decrease in surface states density and the second is by Aspnes [Surf. Sci. 132 (1983) 406] who has assumed a shift in surface Fermi level. Our result, using MIS structures as test (on untreated and treated surfaces) of interface quality is in a good agreement with Aspnes' proposal. We have found in fact that Heller's treatment shifts surface Fermi level to valence band and increases the surface state density. We assume that a generation recombination process that can probably be produced in the space charge region accounts for the observed kinetics of these states, which behave as hole traps. The fraction of a monolayer of ruthenium has been evidenced by means of radioactive tracer technique. We have concluded that these treatments do not improve MIS behavior. The main interest of this treatment remains the enhancement of electronic transfer kinetics at GaAs electrolyte solution interface.

Modification of the surface of GaAs by Ru3+ adsorption leads to a change in Schottky barrier heights of Al/GaAs junctions for both n- and p-type. From our measurements, we have inferred that the surface Fermi level, when compared to the commonly measured pinning position in Al/GaAs structures, is shifted by about 0.1 eV towards the valence band edge.

International audience; In order to investigate the performance of polycrystalline silicon (pc-Si) p(+)in(+) or n(+)ip(+) solar cells deposited by LPCVD technique, two-dimensional numerical resolution of transport equations in semiconductors devices (Poisson's and continuity equations of electrons and holes) is used. The geometrical model assumes that the pc-Si layer is composed by single crystalline grains separated by amorphous silicon transition zones commonly called grain boundaries which are perpendicular to the growth surface and which include the usual density of states (DOS) with exponential band-tails and Gaussian distributed deep levels. From the simulated results of the illuminated I-V characteristics under AM 1.5 solar spectrum, it is found that the photovoltaic parameters (short circuit current J(SC), conversion efficiency eta, open circuit voltage V-OC and fill factor FF) are strongly sensitive to pc-Si quality layer in terms of grain size, intrinsic layer.

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In this paper, electrical characterisation and analytical modelling of current-voltage ( I - V ) and capacitance-voltage ( C - V ) for Hg/InN/n-InP Schottky structures are investigated. We have studied electrically thin InN films realised by the nitridation of InP(100) substrates using a glow discharge source (GDS) in ultra high vacuum. So, we have calculated, using I - V and C - V measurements, the ideality factor n , the saturation current I s , the barrier height

We present in this article current-voltage I(V) and capacitance-voltage C(V) characteristics of Schottky diodes based on SiC. These diodes have different surfaces of Schottky contact. The effect of the surface on the behaviour of the diode is studied. Different current transport mechanisms are revealed from measurements. In addition to thermionic current, other currents are added like the recombination current, tunnelling current and leakage current. Different parameters are extracted from I(V) and C(V) characteristics, such as ideality factor, barrier height, series resistance, doping and the density of interface states.