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The use of semiconductors based on abundant and less expensive materials in photovoltaic industry has grown since electricity consumption has increased, alloys such as Cu2ZnSn(S1-xSex)4 have recently attracted attention, due to its structural, optical and electronic properties which make it a very promising candidate as an absorber layer in photovoltaic applications. The lattice mismatch of Cu2ZnSn(S1-xSex)4 with Cu2NiGeS4 as substrate for solar cell architecture reveals that low Se content (0.1≤x≤0.4) is favorable, and thus, by reducing Se content from 40 to 10% induces a decrease in optical parameters such as refractive index from 5.475 to 3.834 for near-infrared wavelengths, and both extinction and absorption coefficients are from 0.478 to 0.211 and from 7.956×104 to 6.912×104 cm-1, respectively, for almost along the visible spectrum. Additionally, the bandgap energy of Cu2ZnSn(S1-xSex)4 in kesterite structure increases from 1.267 to 1.442 eV at room temperature, while the compressive strain of the epitaxial layer reduces from 3.93 to 2.39% and from 4.62 to 3.17% on the growth plane and following the direction of growth, respectively. [ABSTRACT FROM AUTHOR]

This paper focuses on studying and simulating a GaAs1-xPx/Si1-yGey/Ge triple-junction solar cell structure. First, the strain and the bandgap energy associated to the SiGe layer have been studied. The optimal germanium concentration is 0.88 with a strain around 0.45%. Then, the phosphor concentration effect on the strain and the bandgap energy of the upper layer GaAs1-xPx/Si0.12Ge0.88 has been optimized. At room temperature, the optimal output parameter reach Jsc=34.41mA/cm², Voc=1.27V, FF=88.42% and =38.45% for an absorber thickness of 4.5µm and x=0.47, with a strain that doesn't exceed 1.5%. This study has enabled us to design a high-efficiency, low cost 3J solar cell. [ABSTRACT FROM AUTHOR]

In this paper, we focus on optimizing the solar performance of a CZTSSe-based solar cell by adjusting the zinc and sulfur concentrations in the CdZnS buffer layer and the quinary absorber CZTSSe. The state-of-the-art work is to combine the ZnS and CdS binaries into CdZnS ternary used as a buffer layer in both CZTS- and CZTSSe-based solar cells. An overall study of its properties is carried out taking into account the strain present at the heterointerface, defect density, bandgap energy and the interface state density. As a result, the highest efficiency η = 14.59% was achieved with a sulfur content of 0.55 and a zinc content of 0.70 to bandgap energies of 1.25 and 3.12 eV for CZTSSe and CdZnS materials, respectively. Our simulation is validated by the reproducibility of solar cell performance under the same conditions, and an enhancement of the conversion efficiency of about Δη = 5.55% will be achieved when the CdS layer is replaced by CdZnS in the ZnO/CdS/CZTSSe/Mo/Glass solar device. [ABSTRACT FROM AUTHOR]

Summary: This effort is founded on the modeling and simulation of the GaAsPN/GaP quantum dot (QD) solar cell. This quaternary alloy is one of the III‐V semiconductors, which gained importance in the recent years for optoelectronic applications. This importance comes from the fact that the quaternary GaAsPN can be a well‐grown lattice matched to GaP and Si substrates and to the bandgap that can be decreased drastically with the incorporation of nitrogen and arsenic into GaP, improving consequently the absorption and the wavelengths near the red part. These qualities make GaAsPN a good candidate for the growth on the Si substrate and low‐cost solar cell fabrication. The optical properties of GaAsPN/GaP QDs, such as strain, critical thickness, bandgap energy, the external quantum efficiency, and absorption coefficient, have been reported. The heterostructures consist of GaAs0.18P0.814N0.006 QDs separated by GaP barrier layers. The width and thickness of QDs are about 5 and 5 nm, respectively. Our results have been shown that 20 GaAs0.18P0.814N0.006/GaP QD layers produce a short‐circuit current of about 3.55 mA/cm2 and an efficiency of about 7.5%. In addition, we will be able to extend the absorption edge of a GaP solar cell from 0.48 μm to 0.5 μm for the same QD number layers inserted. The temperature effect on efficiency is considered. [ABSTRACT FROM AUTHOR]

The objective of this work is to simulate and optimize the physical properties of the quaternary semiconductor InGaAsP deposited on InP substrate, in order to enhance the efficiency of photovoltaic cells through the optimization of the bandgap and the absorption coefficient. To this end, the impact of the Gallium and Phosphorus concentrations on the strain as well as on the bandgap energy were studied. We have found that the absorption coefficient increases with the strain to reach 4.4 × 104 cm−1, thus, the strain allows to provide additional flexibility on the structure of solar cells and makes the alloy InGaAsP/InP promising for the design of photovoltaic cells based on the quaternary InGaAsP compound. [ABSTRACT FROM AUTHOR]

• We report the modelling and optimization of a solar cell based on new material using SCAPS software. • A high absorption coefficient was found. • The influence of thickness, temperature, resistances and defects on the different electrical parameters. • A high conversion efficiency was obtained under optimum parameters. • A respectable compatibility has been shown compared with the results of wxAMPS software. Based on several semiconductor research, we have studied one of the new semiconductors, due to its exciting physical proprieties that in turn solve some problems in the photovoltaic's industry. We have divided this work into two parts. The first part, is to study the optical proprieties of ZnSnN 2 , as calculation of the absorption coefficient, bandgap, reflection coefficient, and transmission coefficient. As for the second part, a study of some parameters that affect the efficiency of p-CuCrO 2 (CCO)/ n-ZnSnN 2 (ZTN) solar cell using SCAPS-1D software, and our results are compared with the results of another software (wxAMPS), where results showed great compatibility with the presence of weak uncertainty. We have studied the influence of many parameters such as the thickness of the absorber layer (n-ZnSnN 2), the thickness of the buffer layer (p-CuCrO 2) , the temperature, the series resistance (R s), the shunt resistance (R sh) and the defect density on the performance of ZnSnN 2 solar cells which included in the real device. The photovoltaic parameters have been calculated using AM1.5G solar irradiance at the intensity of one sun, a temperature of 300 K, and considering the flat band condition at the interface. We have been achieving a high-efficiency of η ≈ 22% without defects. Given the characteristics of this new semiconductor ZnSnN 2 , which composed of earth-abundant, non-toxic and inexpensive element, as well as a high absorption coefficient, it can be considered as an alternative for PV and optoelectronic applications. [ABSTRACT FROM AUTHOR]

This paper reports simulations of gradual bandgap CIGS absorber and its impact on the characteristics of a solar cell. The bandgap of the CIGS absorber varies linearly and drops from E gmax (at the junction limit) to E gmin (in the vicinity of the rear contact).We introduce an effective absorption coefficient based on this variation. We will demonstrate that this gradual profile contributes to an improvement up to 171 mV of the open circuit voltage V oc of the cell that is linked to the modification of the internal electrical field distribution within the absorber. However, a joint reduction of 1.50 mA/cm 2 of short circuit current density, J sc , is observed. Overall, the conversion efficiency increases from 19.2%, for a uniform bandgap absorber structure, to 24.9% in that case of gradual bandgap. Additionally, we investigate the impact of absorber thickness and temperature on cell characteristics. [ABSTRACT FROM AUTHOR]

The electrical properties of InAsP/Si quantum dot solar cell (QDSC) are numerically studied and analyzed in this paper. Many effects like number of quantum dot (QD) layers inserted and Arsenic content of InAs x P 1-x on photovoltaic properties such as current density-voltage J-V and the external quantum efficiency (EQE) are investigated. Our results have been shown that the optimal Arsenic content is 0.6. With 30 InAsP/Si QDs layers, relative enhancements of about 7% and 6.70% of short-circuit current and efficiency are achieved, respectively. Otherwise, the absorption range edge of low energy photons was extended from 1120 to 1200 nm. This reveals that introduction of QDs in the intrinsic region of p -i- n Silicon (Si) solar cell enhances significantly the device characteristics beyond what has been reported for conventional semiconductor-based solar cells. [ABSTRACT FROM AUTHOR]

In this work, the performance of solar cell based on CdS-n/Cu 2 ZnSnS 4 -p hetero-junction is numerically simulated. The aim of the study is to investigate the influence of thickness, defects density and bandgap energy of absorber layer CZTS and the thickness of the buffer layer CdS of the solar cell on electrical parameters J sc , V oc , FF and efficiency η of the cell. The results of our simulation allowed us to optimize the parameters above mentioned in order to get the best efficiency at the optimal band gap which corresponds to the maximum of the solar spectrum with optimal values of the electrical performances of the cell. This results lead to develop CZTS solar cells with high efficiency and low cost and give a help full indication for fabrication process. [ABSTRACT FROM AUTHOR]

In recent years, the development of quantum well solar cells QWSCs (Quantum Well Solar Cells) has generated a great deal of interest. These configurations have shown good promise to optimize the low conversion efficiency of conventional solar cells because of the high rate of absorption losses present in them. In this work, we are interested in modeling and simulation of two different structures of solar cells, a simple solar cell based on silicon Si and a quantum well solar cell SiGe/Si. When a solar cell is compared to 80 quantum well layers of Si 0.8 Ge 0.2 with a pin solar cell based on Si. The short circuit current J sc increases from 23.55 to 37.48 mA/cm 2 with a relative increase of 59.15% found. In addition, the limit of the absorption band of the lower energy photons extends from 1100 nm to 2000 nm. [ABSTRACT FROM AUTHOR]

Abstract: This work concerns the study and the simulation of a structure containing II-VI semiconductor for photovoltaic application. We studied the influence of the zinc concentration on the various parameters of the alloy Cd1-xZnxTe epitaxied on a CdTe substrate. Indeed, the insertion of zinc increases the band gap of the alloy, which is not ideal to absorb the maximum of the solar spectrum, but for low concentrations of zinc the Cd1-xZnxTe ternary material becomes attractive in the photovoltaic field. We have shown that for a Zinc composition (x) = 5%, the band gap is 1.52eV. And if x = 20%, the gap is 1.62eV.Our simulation studies have demonstrated that by an introduction of a specific Zinc concentration, we successfully simulated the achieving of 19% efficiency for solar devices. [Copyright &y& Elsevier]

Abstract: The aim of our study is the development and simulation of thin films structure based on CuIn1-xGaxSe2 semiconductors alloys to improve the conversion efficiency of solar cells. We studied and simulated the variation effect of the Gallium concentration on some physical and electrical properties (lattice parameter, strain, energy gap, refractive index, absorption coefficient and J (V) characteristic), this in order to optimize the best possible performances for solar cells. Then, we studied the influence of surface state density and temperature on solar devices characteristics. For better performance of our structure based on CuIn1-xGaxSe2, the concentration of gallium must be less than 40% and this to avoid the lattice mismatch with CdS buffer layer. We have demonstrated by simulation models the possibility for efficiency to reach 22% in the case of CuIn1-xGaxSe2 thin films solar cells. [Copyright &y& Elsevier]

Abstract: The objective is to exploit the properties of the GaInNAs/GaAs alloy compressive strain structure to design a laser diode likely to meet the needs of optical communications. Modelling concerns mainly the study of the potentialities of thermal stability and dynamic response offered by these new techniques of electric and optical confinement. Band structure is modelled and typical quantum well properties are illustrated. A thorough study of the structural parameters is undertaken to take into account from the design criteria the temperature sensitivity. Minimising the Auger coefficient in the order of 10−29 cm6/s appears to allow achieving efficient laser diodes production. [Copyright &y& Elsevier]

Abstract: In this paper, we study the effect of the incorporation of nitrogen in strained GaInAs quantum well structures. We evaluate the influence of nitrogen on the conduction band energy by using the band anticrossing model. The incorporation of nitrogen appears to decrease the bandgap energy and increase the emission wavelength. The reduction of energy is due to the interaction of the energy of the conduction band with the level of nitrogen and more the concentration of nitrogen increases, more the energy of the band gap decreases. On the other hand, the emission wavelength increases, the advantage of the incorporation of nitrogen in such structures is to vary the wavelength between 0.980 and 1.3μm while exploiting of course the composition of gallium, composition of nitrogen and the thickness of the quantum well. Less temperature insensitive devices are so intended to be fabricated. [Copyright &y& Elsevier]