Mohamed Al-Hattab

• PhD
• Université Sultan Moulay Slimane

In this paper, we have calculated the optical properties of the different polytypes of GaSe lamellar materials. The calculations are based on the DFT method and is performed using the CASTEP code. All optical properties have been studied in a domain that extends energetically from 10 meV to 35eV and have been measured for a polarization // and ⊥ wi...

The industry has long sought ever more efficient materials, allowing it to meet market demand. For this purpose, doping remains a good choice for improving the properties of a material. The structural, electronic, optical properties of the GaSe1−xSx (x = 0, 0.25, 0.5 and 1) compounds are studied using the pseudopotential method of first principles...

The aim of this work is to study the photovoltaic performance of a solar cell based on GaSe materials using SCAPS-1D simulator. The novelty of this work consists in the use of GaSe lamellar as a buffer layer, this material has not been used at this part of solar cells before, which makes this new study interesting; we had also used a thin film (CIG...

The present study focuses on the structural and optical characterizations of a GaSe thin-film consisting of few layers mechanically exfoliated from bulk GaSe on a flexible PET substrate. The XRD and the RAMAN spectroscopies confirm the high crystallinity of our material and show that it belongs to the hexagonal ε-GaSe polytype with a mean crystalli...

This study explores the electronic and optical properties of the kesterite-type chalcogenide materials Ag2BeSnX4 (X = S, Se, and Te) using the density functional theory (DFT). Our results indicate that these compounds are direct bandgap semiconductors, with bandgap values of 0.51 eV, 0.62 eV, and 0.805 eV for Ag2BeSnS4, Ag2BeSnSe4, and Ag2BeSnTe4,...

In this paper, we have calculated the structural, electronic, and optical properties of chalcogenide stannite Cu2CdSnX4 (X=S, Se, Te) materials. The calculations are based on the density functional theory (DFT) method and are performed using the Cambridge sequential total energy package (CASTEP) code included in the Biovia Material Studio 20 softwa...

The optoelectronic properties of ZnS doped with transition metals (Cu, Cd, Ag, and Au) are systematically investigated by applying first-principles computations based on the density functional theory (DFT). Various doping concentrations for Cu (5%, 10%, 20%), Cd (5%, 10%, 15%, 20%), Ag (5%, 15%), and Au (5%, 15%, 20%) are explored to examine their...

In this groundbreaking study, we unveil the remarkable structural, electronic, and optical Properties of the newly discovered double perovskite material, K 2 AgBiI 6 , presenting a paradigm shift in materials science. The unique crystal structure and diverse atomic interactions inherent in this double perovskite make it an up-and-coming candidate f...

In this study, a computational analysis based on density functional theory is conducted to study the elastic, mechanical, vibrational, and thermodynamic properties of novel chalcogens, Ag2BeSnX4 (X = S, Se, and Te). We used the generalized gradient approximation (GGA) within the framework of density functional theory (DFT). The mesh parameter value...

Tailoring morphological, elastic, and thermodynamic properties of Ag2BeSnX4 (X=S, Se, Te) kesterites: a computational approach

Copper zinc tin sulfide (CZTS) thin-film solar cells have garnered significant attention in the solar energy sector. This study aims to enhance the performance of CZTS solar cells by replacing the conventional, toxic CdS buffer layer with Zn1−xSnxO (ZTO) for x = 0.2. Utilizing the one-dimensional solar cell capacitance simulator (SCAPS-1D) and info...

In this study, the structural, electronic, and optical properties of pristine graphene and graphene doped/co-doped with (N, Si) atoms are examined using a first-principles investigation. However, pristine graphene is characterized by a unique electronic structure known as the zero band gap (Eg = 0 eV), and this gap was opened up after the addition...

In this paper, XRD patterns and Raman spectra were determined, using the Density Function Theory, to study the structural properties and vibrational modes of the polytype of GaSe materials, ε-GaSe, β-GaSe, γ-GaSe, and δ-GaSe, in different temperatures. Room temperature X-ray diffraction (XRD) analysis revealed crystal phases consistent with those e...

Solar cells based on CIGS have outperformed many thin film solar cells using other absorbers. A prospective CIGS active layer-based SC with an ITO/CdS/CIGS/CNGS hetero-structure, with a CdS buffer layer, ITO window layer, and CNGS in dual role: as extra absorber layer, and Back Surface Field (BSF) was suggested in this article. Through the utilizat...

We have examined the effect of hydrostatic pressure on the reflection in a heterostructure composed of \(N\) multiple quantum wells. The super-cellular structure is formed of a GaAs-based quantum well (QW) sandwiched by relatively thin AlxGa1−xAs barriers with a high \(x=74\%\) Al content. We evaluated the effect of changing the number of quantum w...

This research paper consists of a numerical simulation, where we studied the performance of a solar cell with a double-absorber layer. The materials used in this work are similar kesterites based on Cu2FeSnS4 (CFTS) and Cu2BaSnS4 (CBTS), where CFTS is the main absorber with Eg = 1.5 eV, and CBTS is the extra absorber with Eg = 1.9 eV. The use of bo...

The majority of optoelectronic devices are composed mostly of quantum well heterostructures. The primary attraction of this kind of structure is the energy levels discretization that charge carriers can access due to confinement of the charge carriers in the quantum well in accordance with growth direction. The various transition energies will be d...

First principal computations have been made to explore the optical and electronic characteristics of Cs2AgBiX6 (X=Cl, Br, I) double perovskite. To determine the band gap energy we have used the GGA potentials. The values found for I, Cl, and Br are 0.815, 1.417, and 1.836 eV, respectively. According to our numerical simulation, the Cs2AgBiX6 (X=Cl,...

This work exhibits a new theoretical approach about a 2T Tandem solar cell made of two cells: CFTS/Si. For maximum benefit, careful consideration must be given to the selection and performance enhancement of both cells. In order to achieve good results, the bottom and top cells are independently analyzed and optimized to set the best structure for...

In this paper, we have performed a complementary and comparative analysis between an experimental and simulation study of the CIGS/CdS bulk heterojunction solar cell. The electrical parameters of this heterojunction modeled by a diode in the presence of parasitic resistances (R s ; R sh), are determined by studying the properties of the (I-V) chara...

In this work a GaSe/CdS thin layers structure of a solar cell was digitally processed by the SCAPS-1D simulation program where GaSe is the absorbent material and CdS is the buffer layer; the study of this cell mainly consists in analyzing the effect of the different parameters of the two GaSe and CdS layers such as thickness, concentration career,...

In this study, the physical properties of buckyball (zero-dimensional), Single-Walled Carbon Nanotube (one-dimensional) and graphene (two-dimensional) nanostructures, were investigated using the density functional theory (DFT) calculations. The Visualizer module of Material Studio software is used to construct the structures of these materials. The...

In the present work, computational analysis based on density functional theory is carried out for the optical properties of new kesterite materials Ag 2 BeSnX 4 (S, Se, Te). We used a generalized gradient approximation (GGA) function. On the three structures studied here, the absorption coefficient values are remarkably high of order (10 4 cm − 1)....

This research uses the SCAPS-1D simulation tool to present a numerical simulation investigation of unique Ag2MgSn(S/Se)4 chalcogenide materials. In this paper, the impact of the absorbing films width and doping density on the two cells has been tuned and thoroughly examined, the upper cells with broad gaps (1.63 eV) and the lower cells with narrow...

The objective of this research is to look at how anisotropic mechanical stresses affect the structural, elastic, and electronic properties of various GaSe polytypes. Density functional theory (DFT) was employed in all calculations. Consistent and precise calculations as well as descriptions of trade-off and correlation effects were performed using...

With a large-band gap top cell and a low-band gap bottom cell, double-junction tandem solar cells have a huge potential to exceed existing single-junction photovoltaic technology. To fully benefit, serious attention must go into the choice and performance amelioration of both cells. Tandem solar cells with two terminals (2 T) are highly efficient i...

In this work, we studied and simulated a solar cell based on CIGS/CdS/ZnO. We have optimized the photovoltaic parameters by varying the thickness and the concentration of acceptors and donors of the different canapes of the cell. Simulation calculations have shown that the CIGS/CdS/ZnO based solar cell provides a photovoltaic conversion efficiency...

In the present work, we have considered an unconstrained asymmetric quantum wells based on GaN/AlInN with 17.7% of Indium in the barrier materiel. Three energy levels could be confined thus giving authorized transitions. Our calculations were made in parabolic and non-parabolic cases. In the case of a small well width Lw, the transition E12 is loca...

In the present work, we have considered an unconstrained asymmetric quantum wells based on GaN/AlInN with 17.7% of Indium in the barrier materiel. Three energy levels could be confined thus giving authorized transitions. Our calculations were made in parabolic and non-parabolic cases. In the case of a small well width Lw, the transition E12 is loca...