Ahmed Ennaoui

Institut de Recherche en Énergie Solaire et en Énergies Nouvelles (IRESEN) · Photovoltaics

Many sites with high solar radiation like MENA regions face high dust loads that reduce the efficiency generation of solar plants. In this context, this paper provides an overview of dust adhesion mechanism on the surfaces of concentrated solar power (CSP) mirrors. The assessment of dust adhesion was performed on the hydrophilic/hydrophobic glasses...

Phosphorene, a two-dimensional (2D) material obtained by chemical and mechanical exfoliation of its bulk structure named black phosphorus, has recently been of great importance because of its interesting properties. The intercalation of lithium and sodium in phosphorene multilayer can modify the reordering atoms in the structure lead to different p...

This study presents the results of theoretical and experimental investigations of zinc oxide (ZnO) and aluminum-doped zinc oxide (AZO) thin films, prepared by RF magnetron sputtering. The structural, optical and morphological properties were examined, and the results show that the AZO thin films exhibit a higher optical transmittance compared to in...

Phosphorene, a new two-dimensional material, was investigated theoretically as a promising photocatalyst material. The structural and electronic properties of phosphorene were studied using hybrid functional based HSE approximation. The effect of the adsorbed molecules on the phosphorene surface was studied for various chemical elements, such as wa...

Motivated by recent works dealing with electronic properties and high carrier mobility of monolayer materials and their potential applications in nano thick solar cells, we investigate the electronic properties and performance of new nano thick solar material based on GeSe/SnS hetro-bilayer. The calculations are performed using DFT calculations wit...

Phosphorene is a new two-dimensional material that has recently attracted much attention owing to its fascinating electrical, optical, thermal and chemical properties. Here, we report on high-quality exfoliation of black phosphorus nanosheets, with controllable size produced in large quantities by liquid-phase exfoliation using N-methyl-2-pyrrolido...

This paper presents an innovative approach for the study of the adhesion of dust particles on the surface of CSP reflector mirrors. Three types of CSP mirrors are studied, the first one is the commercial mirror used at NOOR 1 project, the second one is a CSP mirror with hydrophobic amorphous Al2O3 nano-coating and the third one is CSP mirror with h...

The development of an easy and efficient process for producing black phosphorus (BP) remains a bottleneck for the use of BP in large-scale applications. In this work, we present a simple, potentially scalable, and economically viable method for the preparation of high- quality BP from amorphous red phosphorus. BP was synthesized under low pressure...

Condensation contributes to soiling of photovoltaic modules by trapping dust particles and, in certain conditions, leaving a material bridge between particles and the surface after evaporating. This study investigated the effects of four parameters on condensation on soiled surfaces: (i) relative humidity (RH), (ii) surface-dew point temperature di...

Dust accumulates on photovoltaic modules through the additive processes of particle deposition, rebound, and resuspension. These mechanisms are largely controlled by air flow, and have been studied for decades via controlled wind-tunnel experiments and observational outdoor studies. With the rapid deployment of PV in desert regions, there is also a...

Inkjet printing is a promising route for thin film deposition due to its low material wastage and potential of high throughput production. In this work, the inkjet printing technique is used for the deposition of Cu2ZnSn(SxSe1-x)4 (CZTSSe) thin films from Cu-Zn-Sn-S molecular inks. The key step for using the inkjet printing technique is to formulat...

TiO2 thin films with different thicknesses were deposited on glass substrates by using the Ion Layer Gas Reaction (Spray-ILGAR) technique at a substrate temperature of 460°. The effects of deposition time on the morphology and the optical properties of deposited anatase TiO2 thin films are studied. A wide range of characterization techniques such a...

The increasing interest in future energy storage technologies has generated the urgent need for alternative rechargeable batteries. Density functional theory calculations (DFT), including van der Waals interactions, have been carried out in order to evaluate the prospects of a novel 2D material named phosphorene as an anode material for Li, Na and...

Perovskite based solar cells such as orthorhombic hybrid perovskite CH3NH3PbI3 (OHP- CH3NH3PbI3) have shown extraordinary power conversion efficiencies exceeding 20%. Nevertheless, the macroscopic performances of these materials and the microscopic mechanism of the photovoltaic performance of OHP-CH3NH3PbI3 based solar cells are not fully understoo...

The extreme conditions of desert locations put a lot of stress on the components of CSP systems. Solar reflectors, in particular, are sensitive to soiling and abrasion from sand and dust and might see their ability to reflect and concentrate light compromised. Whereas soiling is usually reversible with cleaning, the abrasion of the mirrors' surface...

Solar panels are used to directly convert sunlight into electric current. Associated with a useful range of the solar spectrum is the rest unwanted irradiation, causing the temperature rise in the solar cells, which ultimately reduces the efficiency and power output of most of panels. Furthermore, dust settlement on the surface of panel, also refer...

The scale of a photovoltaics (PVs) field exists between the regional scale and the scale of the air flow on a single PV panel. Field-scaled wind conditions are defined and used in the current study. They are designed after the case of QEERI solar test facility in Doha, Qatar, using a modeling approach based on Computational Fluid Dynamics. The mode...

Soiling can greatly decrease the performance of PV systems in desert regions. There are different ways of measuring soiling in the field and laboratory, such as mass of dust deposited, light transmission reduction, or output of a PV cell. A review of common PV soiling measurement techniques is presented. Also, sunlight angle of incidence is shown e...

The full-potential linearized augmented plane wave method (FP-LAPW) based on the density functional theory (DFT) and Boltzmann's Transport theory, are employed to investigate theoretically the electronic structure, optical and electrical properties of Sc, Ti and V doped rutile SnO2. The FPLAPW based on the new potential approximation known as the T...

In Concentrated Solar Power (CSP) application, top coatings are of tremendous importance as a way to protect the reflective layers form degradation and conserve the efficiency and durability of the mirrors. The choice of Al 2 O 3 as a top-protective coating for CSP reflectors is based on its high stability, hardness and transparency. In this study,...

The rate of soiling of photovoltaic modules depends on environmental parameters such as aerosol concentration, humidity and wind speed. Previously we found low correlations between daily averages of these values and the daily soiling rate of a PV system. In this study we aimed to achieve stronger correlations by increasing the measurement frequency...

In this study, potential sites for concentrated solar power (CSP) installations in Morocco are investigated based on direct normal irradiation (DNI). The DNI data of four Moroccan sites (Missour, Erfoud, Zagora and Tantan) were collected from different satellite databases (NASA SSE, PV GIS-Helioclim, Climate-SAF PVGIS and Solar Med Atlas). However,...

Recently, the transition metal dichalcogenides have attracted renewed attention due to the potential use of their low-dimensional forms in both nano- and opto-electronics. In such applications, the electronic and transport properties of monolayer transition metal dichalcogenides play a pivotal role. The present paper provides a new insight into the...

Although Cu(In,Ga)(S,Se)2 (CIGSe) based thin film solar cells have reached efficiencies exceeding 22% based on vacuum processed CIGSSe absorbers, the supply of indium and gallium might become an issue if CIGSSe thin-film solar cells are produced in very large volumes. It is therefore mandatory to reduce the wastage of indium and gallium during the...

In recent years, novel two-dimensional (2D) materials have attracted much attention due to their unique properties and numerous possible applications [1]. In particular, one of the key domains that can be addressed with the 2D materials refers to the energy conversion and storage [2]. In this context, the novel monolayer group-VI B transition metal...

The solar photovoltaic industry is dominated by crystalline silicon with a global PV market share of 90%. The global PV module production has reached about 40 GW in 2013. Competing with Si PV, thin film photovoltaic modules have reached a market share just below 10%, with dominance by two companies: First Solar for CdTe and Solar Frontier for Cu(In...

At QEERI, the recently launched grand challenge project ATHLOC-PV aims to develop in Qatar an emerging alternative PV technology to reduce the price of the photovoltaic (PV) modules further. This project focus on the development of low cost processes and sustainable thin film materials to obtain cheaper, flexible and durable photovoltaic modules. S...

Recently, monolayer transition metal dichalcogenides (MX2, where M=Mo, W; X=S, Se, Te) have attracted much attention due to their potential use in nano- and opto-electronics [1]. In such applications, their electronic and transport properties are particularly important. Herein, new insight into these properties is presented by studying the complex...

The state of art is shown to develop attractive, low cost, colorful, and device grade dye sensitized solar cells using chemically synthesized ZnO. Metal free organic dyes showing unlike absorption coverage in the visible part of solar spectrum has been used to produce colorful solar cells. By mimicking the basic idea of blending two individual co...

The solar reflectors used in Concentrated Solar Power (CSP) technologies are either front-surface or second-surface mirrors. The advantage of second-surface mirrors over front-surface mirrors is due to the fact that the reflective layer in second-surface mirrors is covered from the front-side by glass, which allows protection against degradation fa...

We report a route to deposit In2S3 thin films from air-stable, low-cost molecular precursor inks for Cd-free buffer layers in chalcopyrite-based thin film solar cells. Different precursor compositions and processing conditions were studied to define a reproducible and robust process. By adjusting the ink properties, this method can be applied in di...

Although PV has made remarkable progress in reducing costs, the absolute cost is highly related to the reliability of system components, which is determined by the life span in which PV remains fully functioning. Longer life is especially required for the solar panels when their initial cost is relatively high and therefore longer life guarantees t...

Photovoltaics (PVs) are the solar harvesting devices currently envisioned to anchor the will of increasing Renewable Energy in Qatar. These devices are planned to be deployed within the next few years to achieve the GW scale. Less oil and gas dependence is important on the very long timescale, as per the perspective of the energy security grand cha...

Inkjet printing technique is a material-conserving technique, which can greatly reduce the production cost by reducing the wastage of materials during the deposition. Additionally, this method can be easily adapted to Roll-to-Roll processing for large-scale application. The most challenging issues that remain open for multi-component system such as...

The state of art is shown to develop attractive, low cost, colorful, and device grade dye sensitized solar cells using chemically synthesized ZnO. Metal free organic dyes showing unlike absorption coverage in the visible part of solar spectrum has been used to produce colorful solar cells. By mimicking the basic idea of blending two individual colo...

Desert areas are considered to be the most suitable sites for CSP power plant installations due to their high irradiance, principally the direct normal irradiance (DNI), as well as the flat land scape and lower population densities. However, CSP reflector components are exposed to very harsh weather conditions in desert areas, such as wind storms,...

Using first principles calculations based on density functional theory (DFT), the electronic properties of SnO2 bulk and thin films are studied. The electronic band structures and total energy over a range of SnO2-multilayer have been studied using DFT within the local density approximation (LDA). We show that changing the interatomic distances and...

Titanium Dioxide is an important material that is used in many industrial applications such as photo-catalysis, glass-defogging, self-cleaning, waste water purification and anti-bacterial sterilization. The strong photo-catalysis of TiO2, and therefore its ability to decompose dirt and organic contaminants makes it an excellent top-protective layer...

In this work, we present the deposition of Cu2ZnSn(S,Se)4 CZTSSe absorbers by inkjet printing and their application in thin film solar cells. Inkjet printing is a promising approach, which can be easily adapted for industrial production. An attractive issue when using inkjet printing is its little demand on materials and low waste production during...

Supplementary

http://onlinelibrary.wiley.com/doi/10.1002/advs.201500028/abstract

Thin film solar cells already benefit from significant material- and energy savings. By using photon management, the conversion efficiency and the power density can be enhanced further, including reduction of material costs. In this work, micrometer-sized Cu(In,Ga)Se2 (CIGS) thin film solar cells were investigated under concentrated (up to 50x) whi...

This work consists on the improvement of first surface silvered thick glass mirrors. Several types of CSP mirrors based on different Physical Vapor Deposition techniques (PVD) and the presence or absence of the copper protective back layer were prepared: ([Ag Sputtered], [Ag Evaporated], [Cu Sputtered-Ag Evaporated], [Cu Evaporated-Ag Sputtered], [...

Defect states in Cu 2ZnSn(SxSe1−x)4 thin films with x = 0.28, 0.36, and 1 were studied by combining photoluminescence (PL) and modulated surface photovoltage (SPV) spectroscopy. A single broad band emission in the PL spectra was observed and can be related to quasi-donor-acceptor pair transitions. The analysis of the temperature dependent quenching...

ABSTRACT: CuZnSn(S,Se)4 (CZTSSe) with an optical band gap around 1.0-1.5 eV and absorption coefficient over 104 cm-1 is the optimal candidate for photovoltaic application. Although the conversion efficiencies of the best CZTSSe-based solar cells (12.6 % [1]) are still far below the Cu(In,Ga)Se2 (CIGS) based solar cells (21.7 % [2]) CZTSSe material...

CuZnSn(S,Se)4 (CZTSSe) with an optical band gap around 1.0-1.5 eV and absorption coefficient over 10 4 cm -1 is the optimal candidate for photovoltaic application. Although the conversion efficiencies of the best CZTSSe-based solar cells (12.6 % [1]) are still far below the Cu(In,Ga)Se2 (CIGS) based solar cells (21.7 % [2]) CZTSSe material has been...

Article is mainly emphasized on the step-wise development of dye sensitized solar cells based on solution processed ZnO films by using cost effective two-step chemical route and with the use of low cost Eosin-Y dye as a sensitizer. The growth of ZnO includes the formation of seed layer followed by the growth of petal like structure consisting of in...

Simple wet chemically grown ZnO with interconnected nanoparticles network having cactusmorphology was successfully demonstrated as a photoanode towards dyesensitized solarcell applications with two different dyes, namely, D149 and N719 with the device efficiencies of 3.43% and 3.09%, respectively

The development of light concentrating techniques and setups for Cu(In,Ga)Se2 thin film solar cells can help to improve their overall device efficiency further whilst also reducing raw material usage. Combined with a cell minimization from millimeter to micrometer scale, the heat transfer and cooling in the solar cells is optimized as well as limit...

We report a rapid, simple, and room-temperature electrophoretic deposition (EPD) method for the fabrication of Cu2ZnSnS4 thin film [1,2]. The electrophoretic electrodes are Indium tin oxide (ITO) and molybdenum substrates. EPD allows on-demand patterning of materials with negligible waste and small environmental footprint. EPD is a two-step process...

In this work we report on the formation of the Cu2ZnSn(Sx,Se1-x)4 (CZTSSe) thin film absorbers from copper-zinc-tin-sulfur inks consisting of mixing binary and ternary chalcogenide nanoparticles (NPs) such as SnS, ZnS and Cu3SnS4 (CTS) [1]. The chalcogenide nanoparticles were synthesized in-house by a colloidal route [1-3]. The chemical composition...

In this work we discuss the development of low cost produced Cu2ZnSn(SxSe1-x)4 (CZTSSe) absorber layers deposited on ZnO nanorods (NRs) substrates. This concept consists of preparing highly absorbing material (CZTSSe) on nanostructured substrates (ZnO NRs) which have a very high surface area allowing the use of very thin layers of CZTSSe while stil...

Simple wet chemically grown ZnO with interconnected nanoparticles network having cactus morphology was successfully demonstrated as a photoanode towards dye sensitized solar cell applications with two different dyes, namely, D149 and N719 with the device efficiencies as 3.43% and 3.09%, respectively

Copper zinc tin sulfide Cu2ZnSn(SxSe1-x)4 (CZTSSe) has attracted significant attention in the past few years as a next generation absorber material for the production of thin film solar cells on large scales due to the high natural abundance of all constituents, tunable direct band gap energy ranging from 1.0 to 1.5 eV, and large absorption coeffic...

A method of non-vacuum synthesis of Kesterite thin films with reduced deposition time to less than 5 min based on electrophoretic deposition (EPD) of Copper zinc tin sulfide (Cu2ZnSnS4 or CZTS) Nanocrystal in liquid solvents is presented. The method can be used as an alternative to spin-casting and printing for large-area, high-throughput processin...

In this work we discuss the development of cheaply produced Cu2ZnSn(SxSe1-x)4 absorber layers on ZnO nanorods (NRs). The concept of this work is preparing highly absorbing material on nanostructured substrates which have a very high surface area allowing the use of very thin layers of CZTS while still absorbing sufficient sunlight. This can be achi...

Lattice positions of Sn in kesterite Cu2ZnSnS4 and Cu2SnS3 nanoparticles and thin films were investigated by XANES (x-ray absorption near edge structure) analysis at the S K-edge. XANES spectra were analyzed by comparison with simulations taking into account anti-site defects and vacancies. Annealing of Cu2ZnSnS4 nanoparticle thin films led to a de...

Cu2ZnSnS4 (CZTS), and Cu2ZnSn(Se,S)4 (CZTSSe) absorbers have been grown successfully from copper-zinc-tin-sulfur inks using chemical routes. In this work we report on current status of CZTS(Se) solar cells and we highlight our processing of copper-zinc-tin-sulfur inks consisting of mixing binary and ternary chalcogenide SnS, ZnS and Cu3SnS4 (CTS) n...

a b s t r a c t a r t i c l e i n f o Available online 25 October 2012 Keywords: Cu 2 ZnSnS 4 CZTS Optical properties Raman spectroscopy Photoluminescence Cu 2 ZnSnS 4 (CZTS) has been considered as an alternative absorber layer to Cu(In,Ga)Se 2 due to its earth abundant and environmentally friendly constituents, optimal direct band gap of 1.4–1.6 e...

Cu2ZnSnS4 (CZTS) nanocrystal (NC) layers were deposited successfully by electrophoretic deposition (EPD) on molybdenum and fluorine doped tin oxide coated glass substrates. This approach combines a non-vacuum coating technique known for its industrial eligibility to a solar absorber material consisting solely of non-toxic and earth abundant element...

Cu2ZnSn(SxSe1−x)4 (CZTSSe) layers deposited from multi-component nanoparticle inks were characterized by modulated surface photovoltage (SPV) spectroscopy to investigate the effect of annealing conditions. The SPV signals increased strongly with decreasing sulfur content. Band gaps were obtained in terms of SPV onset energy. A diffusion length of a...

Quaternary semiconductors, Cu2ZnSnS4 and Cu2ZnSnSe4 which contain only earth- abundant elements, have been considered as the alternative absorber layers to Cu(In,Ga)Se2 (CIGS) for thin film solar cells although CIGS-based solar cells have achieved efficiencies over 20 %. In this work we report an air-stable route for preparation of CZTSSe thin film...

In a previous work we observed the formation of CZTSSe by the reaction between CTS and the ZnO-Nanorod (NR) array. The latter vanished during the annealing process [1]. However, our objective is the use of ZnO-NRs as a nano-structured substrate while keeping the advantage of high surface/volume ratio. Therefore, in order to prevent from interdiffus...

Thin film PV technologies have been advanced considerably in the last few years and have demonstrated the potential to achieve low cost and high throughput production. Binary and multinary chalcogenide materials with their direct gap and high absorption coefficients allow for the fabrication of thin-film photovoltaic modules with minimized material...

In the present investigation, we report the reproducible simple solution chemistry towards synthesis of ZnO nanostructure on fluorine doped tin oxide (FTO) coated glass substrate in aqueous medium at low temperature (>100 °C). The different preparative parameters such as deposition time, bath temperature, concentration of precursor solution, pH of...