Ordering in ternary nitride semiconducting alloys

We present a thorough theoretical study of ordering phenomena in nitride ternary alloys GaInN, AlInN, and AlGaN. Using the Monte Carlo approach and energetics based on the Keating model we analyze the influence of various factors on ordering in bulk crystals and epitaxial layers. We characterize the degree of both short range order (SRO) and long ranger order (LRO) for different compositions, temperatures and for substrates associated with different epitaxial strain. For the description of the SRO the Warren-Cowley parameters related to the first four coordination shells are used. The LRO is detected by means of the introduced sim-LRO parameter, based on the Bragg-Williams approach. The description of the observed long-range ordering patterns and conditions for their occurrence follows

Bor karbür nanoyapıların yapısal özelliklerinin mekanik ve ısıl işlemler etkisinde incelenmesi: molekül dinamiği benzetişimleri.

Structural properties of various boron-carbide nanosystems with different sizes have been investigated by performing classical molecular dynamics simulation techniques at several temperatures. Studied boron carbide systems are icosahedral nanoribbons and nanosheets, graphene like armchair and zigzag type of monolayer and bilayer boron carbide nanoribbons and nanosheets, armchair and zigzag type of boron carbide nanotubes, cubic form nanorods and nanosheets. Stillinger-Weber potential energy function parameters modified for boron carbide systems have been used for atomistic simulations. In order to investigate the size and thermal effect, models have been prepared generally in four different sizes and simulated at 1 K, 300 K, 600 K and 900 K. Uniaxial strain effect along the model direction has been investigated at two different strain rates (slow and fast) for nanoribbon, nanotube and nanorod structures. Similarly biaxial strain effect has been studied for nanosheet structures.Ph.D. - Doctoral Progra

Structure and lattice dynamics of GaN and AlN: ab-initio investigations of strained polytypes and superlattices

Due to its band-gap energy, gallium nitride (GaN) is well-suited for light emission in the blue spectral region. By alloying with aluminium and/or indium, an energetical range even wider than the whole visible spectrum can be covered. For electronic devices based on group-III nitrides, the influence of strain is a non-negligible intrinsic physical effect. An easy way to experimentally evaluate the strain is the monitoring of lattice vibrations via Raman spectroscopy. With experimental data providing a reliable reference for the strain effects not being available, it is desirable to obtain them from a full quantum-mechanical treatment of the material via first-principles calculations. In this work, the strain dependence of the structural and dielectric properties and of the phonon frequencies of the cubic and the hexagonal polytype of GaN and AlN as well as of short-period superlattices are investigated by ab-initio methods. Three types of strain are considered, corresponding to the application of hydrostatic pressure, of an isotropic biaxial stress in the basal plane, and of a uniaxial pressure along the crystal axis. After a careful internal relaxation of the structures for given external stress, the dielectric constant, Born effective charges and phonon frequencies are calculated using density-functional perturbation theory. Since typical structural changes are of the order of one hundredth of the lattice parameters, to resolve these changes to a precision of a few percent the lattice parameters themselves have to be determined to a precision of 1E-4, which indeed can be achieved. The elastic properties of GaN and AlN are characterized in terms of ratios of the elastic stiffness constants, which allow for a critical comparison with literature data; unreliable ones are pointed out. The calculated pressure behavior of the phonon modes compares rather well to experimental results. The observed increase of the LO-TO splitting results from a reduced dielectric screening, not from an increase in ionicity. A frozen-phonon calculation shows that the softening of the low-frequency E2 mode is mainly caused by an increased destabilization due to the Ewald energy, which is differently counterbalanced in GaN and AlN by the other contributions to the total energy. From the strain dependences, phonon mode coefficients and deformation potentials are obtained, which agree with measured values for GaN; for AlN, no other published values are available. Seeming discrepancies between experimental and theoretical results can be widely resolved using suitable parameters and correct stress-strain relations. We find that the stress obtained from biaxial-strain-induced shifts of the high-frequency E2 phonon should be higher than determined by other authors. The short-period superlattice show a structural relaxation behavior differing significantly from the bulk one. Their phonon modes are grouped in separate frequency regions for LO and TO modes as well as for acoustic ones, they exhibit properties typical both for thicker superlattices as well as for a bulk material of its own kind. Folded AlN-confined TA modes appear due to the mutual strain of the GaN and AlN layers. For all superlattices, independent of the number of layers and the polytype, the following special features are found, which can be considered as intrinsic properties: All but one of the TO modes are confinded modes, with the propagating one being found in the GaN frequency region, well separated from the AlN range; it shows a vibrational pattern similar to a bulk zone-center TO mode. In the gap between the AlN- and GaN-confined TO modes an interface mode exists, showing strong angular dispersion. The uppermost LO mode changes its polarization direction and it is strongly IR active, thus for all propagation directions it couples to the electric field, in complete analogy to the polar LO mode of bulk material

Boîtes quantiques de semi-conducteurs nitrures pour des applications aux capteurs opto-chimiques

Ce travail de thèse a porté sur la synthèse de boîtes quantiques (BQs) de semi-conducteurs nitrures orientés (11-22) ou (0001) par épitaxie par jets moléculaires à plasma d'azote, pour des applications aux capteurs chimiques pour la détection du niveau de pH, d'hydrogène ou des hydrocarbures dans des environnements gazeux ou liquides. Dans la première partie de ce manuscrit, je décri la synthèse des couches bidimensionnelles semi-polaires (11-22) : des couches binaires (AlN, GaN, and InN) et des ternaires (AlGaN et InGaN), qui sont requises pour le contact de référence dans les transducteurs et aussi pour établir une connaissance de base pour comprendre la transition dès la croissance bidimensionnelle à la croissance tridimensionnel des BQs. Un résultat particulièrement relevant est l'étude de la cinétique de croissance et l'incorporation de l'indium dans les couches d'InGaN(11-22). De même que pour InGaN polaire (0001), les conditions optimales de croissance pour l'orientation cristallographique semi-polaire correspondent à la stabilisation de 2 ML d'In sur la surface, en excellent accord avec des calculs théoriques. Les limites de la fenêtre de croissance en termes de température du substrat et de flux d'In sont les mêmes pour les matériaux semi-polaire et polaires. Cependant, j'ai constaté une inhibition de l'incorporation de l'In dans les couches semi-polaires, même pour une température en dessous du seuil de la ségrégation pour l'InGaN polaire. Dans une deuxième étape, j'ai fabriqué des super-réseaux de BQs de GaN/AlN et InGaN/GaN, à la fois dans l'orientation polaire et semi-polaire. Les mesures de photoluminescence et de photoluminescence en temps résolu confirment la réduction du champ électrique interne dans les boîtes semi-polaires. D'autre part, les BQs semi-polaires à base d'InGaN doit relever le défi de l'incorporation d'In dans cette orientation cristallographique. Pour surmonter ce problème, l'influence de la température de croissance sur les propriétés des boîtes quantiques InGaN polaires et semi-polaires a été étudiée, en considérant la croissance à haute température (TS = 650 510 C, où la désorption d'In est active) et à basse température (TS = 460 440 C, où la désorption d'In est négligeable). J'ai démontré que les conditions de croissance à faible TS ne sont pas compatibles avec le plan polaire, tandis qu'ils fournissent un environnement favorable au plan semi-polaire pour améliorer l'efficacité quantique interne de nanostructures InGaN. Enfin, j'ai synthétisé un certain nombre de transducteurs à BQs de GaN/AlN et InGaN/GaN selon les axes de croissance polaire et semi-polaire. Dans chaque cas, les conditions de croissance pour atteindre la fourchette spectrale ciblée (420-450 nm d'émission à avec une couche contact transparente pour des longueurs d'onde plus courtes que 325 nm) ont été identifiés. L'influence d'un champ électrique externe sur la luminescence des transducteurs ont confirmé que la meilleure performance (plus grande variation de la luminescence en fonction de la polarisation) a été fournie par des structures à base de BQs d'InGaN/GaN. Avec ces données, les spécifications des transducteurs opto-chimiques ont été fixées : 5 perides de BQs d'InGaN/GaN sur une couche contact d'Al0.35Ga0.65N:Si). Puis, j'ai synthétisé un certain nombre de ces transducteurs afin d'obtenir un aperçu sur la reproductibilité, limites et les étapes critiques du processus de fabrication. En utilisant ces échantillons, nous avons réalisé un système capteur intégré qui a été utile pour le suivi de la valeur du pH de l'eau.This thesis work has focused on the synthesis of (In)GaN-based quantum dot (QD) structures by plasma-assisted molecular-beam epitaxy (PAMBE), deposited in both polar (0001) and semipolar (11-22) crystallographic orientations, for application as optical transducers for chemical sensors for detection of pH levels, and hydrogen or hydrocarbon concentrations in gas or liquid environments. In the first part of this work, I describe the synthesis of semipolar-oriented two-dimensional layers: binary alloys (AlN, GaN and InN) and ternary alloys (AlGaN and InGaN), which are required for the reference contact of the transducers and set the basic know-how to understand the transition from two-dimensional growth to three-dimensional QD nanostructures. It is particularly relevant the study of indium kinetics and indium incorporation during the PAMBE growth of InGaN(11-22) layers. Similarly to (0001)-oriented InGaN, optimum growth conditions for this semipolar crystallographic orientation correspond to the stabilization of 2 ML of In on the growing InGaN surface, in excellent agreement with first-principles calculations. The limits of the growth window in terms of substrate temperature and In flux lie at same values for polar and semipolar materials. However, I observe an inhibition of the In incorporation in semipolar layers even for substrate temperatures below the segregation threshold for polar InGaN. In a second stage, I report the successful fabrication of superlattices (SLs) of GaN/AlN and InGaN/GaN QDs, both in polar and semipolar orientations. Photoluminescence and time-resolved photoluminescence confirmed the reduction of the internal electric field in the semipolar GaN/AlN QDs in comparison with polar structures. On the other hand, semipolar InGaN QDs must face the challenge of In incorporation in this crystallographic orientation. To overcome this problem, the influence of the growth temperature on the properties of the polar and semipolar InGaN QDs has been studied, considering growth at high temperature (TS = 650 510 C, where In desorption is active) and at low temperature (TS = 460 440 C, where In desorption is negligible). I demonstrate that low-TS growth conditions are not compatible with polar plane whereas they provide a favorable environment to semipolar plane to enhance the internal quantum efficiency of InGaN nanostructures. Finally, I have synthesized a number of GaN/AlN and InGaN/GaN QD optical transducers, grown in polar and semipolar orientations. In each case, the growth conditions to attain the targeted spectral range (emission at 420-450 nm with buffer transparent for wavelengths shorter than 325 nm) were identified. The influence of an external electric field on the luminescence of the transducers confirmed that the best performance (larger variation of the luminescence as a function of bias) was provided by InGaN/GaN QD structures. With this feedback, the specifications of the targeted opto-chemical transducer structures have been established (5 InGaN/GaN QD layers on Al0.35Ga0.65N:Si). Then, I have synthesized a number of InGaN/GaN opto-chemical transducers in order to get an insight on the reproducibility, limitations and critical steps in the fabrication process. Using these samples, we have achieved an integrated sensor system based on polar InGaN QD SLs, and the system was useful for monitorization of the pH value of water.SAVOIE-SCD - Bib.électronique (730659901) / SudocGRENOBLE1/INP-Bib.électronique (384210012) / SudocGRENOBLE2/3-Bib.électronique (384219901) / SudocSudocFranceF

Boîtes quantiques de semi-conducteurs nitrures pour des applications aux capteurs opto-chimiques

This thesis work has focused on the synthesis of (In)GaN-based quantum dot (QD) structures by plasma-assisted molecular-beam epitaxy (PAMBE), deposited in both polar (0001) and semipolar (11-22) crystallographic orientations, for application as optical transducers for chemical sensors for detection of pH levels, and hydrogen or hydrocarbon concentrations in gas or liquid environments. In the first part of this work, I describe the synthesis of semipolar-oriented two-dimensional layers: binary alloys (AlN, GaN and InN) and ternary alloys (AlGaN and InGaN), which are required for the reference contact of the transducers and set the basic know-how to understand the transition from two-dimensional growth to three-dimensional QD nanostructures. It is particularly relevant the study of indium kinetics and indium incorporation during the PAMBE growth of InGaN(11-22) layers. Similarly to (0001)-oriented InGaN, optimum growth conditions for this semipolar crystallographic orientation correspond to the stabilization of 2 ML of In on the growing InGaN surface, in excellent agreement with first-principles calculations. The limits of the growth window in terms of substrate temperature and In flux lie at same values for polar and semipolar materials. However, I observe an inhibition of the In incorporation in semipolar layers even for substrate temperatures below the segregation threshold for polar InGaN. In a second stage, I report the successful fabrication of superlattices (SLs) of GaN/AlN and InGaN/GaN QDs, both in polar and semipolar orientations. Photoluminescence and time-resolved photoluminescence confirmed the reduction of the internal electric field in the semipolar GaN/AlN QDs in comparison with polar structures. On the other hand, semipolar InGaN QDs must face the challenge of In incorporation in this crystallographic orientation. To overcome this problem, the influence of the growth temperature on the properties of the polar and semipolar InGaN QDs has been studied, considering growth at high temperature (TS = 650–510 °C, where In desorption is active) and at low temperature (TS = 460–440 °C, where In desorption is negligible). I demonstrate that low-TS growth conditions are not compatible with polar plane whereas they provide a favorable environment to semipolar plane to enhance the internal quantum efficiency of InGaN nanostructures. Finally, I have synthesized a number of GaN/AlN and InGaN/GaN QD optical transducers, grown in polar and semipolar orientations. In each case, the growth conditions to attain the targeted spectral range (emission at 420-450 nm with buffer transparent for wavelengths shorter than 325 nm) were identified. The influence of an external electric field on the luminescence of the transducers confirmed that the best performance (larger variation of the luminescence as a function of bias) was provided by InGaN/GaN QD structures. With this feedback, the specifications of the targeted opto-chemical transducer structures have been established (5 InGaN/GaN QD layers on Al0.35Ga0.65N:Si). Then, I have synthesized a number of InGaN/GaN opto-chemical transducers in order to get an insight on the reproducibility, limitations and critical steps in the fabrication process. Using these samples, we have achieved an integrated sensor system based on polar InGaN QD SLs, and the system was useful for monitorization of the pH value of water.Ce travail de thèse a porté sur la synthèse de boîtes quantiques (BQs) de semi-conducteurs nitrures orientés (11-22) ou (0001) par épitaxie par jets moléculaires à plasma d'azote, pour des applications aux capteurs chimiques pour la détection du niveau de pH, d'hydrogène ou des hydrocarbures dans des environnements gazeux ou liquides. Dans la première partie de ce manuscrit, je décri la synthèse des couches bidimensionnelles semi-polaires (11-22) : des couches binaires (AlN, GaN, and InN) et des ternaires (AlGaN et InGaN), qui sont requises pour le contact de référence dans les transducteurs et aussi pour établir une connaissance de base pour comprendre la transition dès la croissance bidimensionnelle à la croissance tridimensionnel des BQs. Un résultat particulièrement relevant est l'étude de la cinétique de croissance et l'incorporation de l'indium dans les couches d'InGaN(11-22). De même que pour InGaN polaire (0001), les conditions optimales de croissance pour l'orientation cristallographique semi-polaire correspondent à la stabilisation de 2 ML d'In sur la surface, en excellent accord avec des calculs théoriques. Les limites de la fenêtre de croissance en termes de température du substrat et de flux d'In sont les mêmes pour les matériaux semi-polaire et polaires. Cependant, j'ai constaté une inhibition de l'incorporation de l'In dans les couches semi-polaires, même pour une température en dessous du seuil de la ségrégation pour l'InGaN polaire. Dans une deuxième étape, j'ai fabriqué des super-réseaux de BQs de GaN/AlN et InGaN/GaN, à la fois dans l'orientation polaire et semi-polaire. Les mesures de photoluminescence et de photoluminescence en temps résolu confirment la réduction du champ électrique interne dans les boîtes semi-polaires. D'autre part, les BQs semi-polaires à base d'InGaN doit relever le défi de l'incorporation d'In dans cette orientation cristallographique. Pour surmonter ce problème, l'influence de la température de croissance sur les propriétés des boîtes quantiques InGaN polaires et semi-polaires a été étudiée, en considérant la croissance à haute température (TS = 650–510 °C, où la désorption d'In est active) et à basse température (TS = 460–440 °C, où la désorption d'In est négligeable). J'ai démontré que les conditions de croissance à faible TS ne sont pas compatibles avec le plan polaire, tandis qu'ils fournissent un environnement favorable au plan semi-polaire pour améliorer l'efficacité quantique interne de nanostructures InGaN. Enfin, j'ai synthétisé un certain nombre de transducteurs à BQs de GaN/AlN et InGaN/GaN selon les axes de croissance polaire et semi-polaire. Dans chaque cas, les conditions de croissance pour atteindre la fourchette spectrale ciblée (420-450 nm d'émission à avec une couche contact transparente pour des longueurs d'onde plus courtes que 325 nm) ont été identifiés. L'influence d'un champ électrique externe sur la luminescence des transducteurs ont confirmé que la meilleure performance (plus grande variation de la luminescence en fonction de la polarisation) a été fournie par des structures à base de BQs d'InGaN/GaN. Avec ces données, les spécifications des transducteurs opto-chimiques ont été fixées : 5 perides de BQs d'InGaN/GaN sur une couche contact d'Al0.35Ga0.65N:Si). Puis, j'ai synthétisé un certain nombre de ces transducteurs afin d'obtenir un aperçu sur la reproductibilité, limites et les étapes critiques du processus de fabrication. En utilisant ces échantillons, nous avons réalisé un système capteur intégré qui a été utile pour le suivi de la valeur du pH de l'eau

Nanostructured Multilayer Ceramic Coatings for Wood-Cutting Tools

Lo sviluppo di questo dottorato di ricerca è stato supportato e finanziato dal progetto europeo Interreg ITA-SLO NANOREGION. La missione del progetto NANOREGION consiste nel costituire un consorzio tra università ed enti di ricerca locali atti a fornire una piattaforma scientifica di supporto alle imprese del territorio comprensivo delle regioni dell'Italia nord-orientale e la Slovenia. In tali regioni, l'impatto economico-sociale dell'industria del legno è rilevante. È noto che nella manifattura di materiali legnosi la necessità di una frequente sostituzione degli utensili da lavorazione, necessaria a garantire gli standard di qualità del prodotto finito, ha un forte impatto sull'economia del processo di lavorazione. Gli utensili da taglio sono generalmente protetti con rivestimenti a film sottile costituiti da materiali duri e refrattari per aumentarne la durabilità, riducendo la frequenza di sostituzione e quindi aumentando la produttività delle aziende. Tuttavia, a causa della natura del legno come materiale da lavorazione e dei rigorosi requisiti tecnici specifici della lavorazione del legno, il rapporto costi/benefici del processo di rivestimento degli utensili si è finora dimostrato non sufficiente a giustificare i costi addizionali legati al processo di rivestimento. Questo risulta in una minore penetrazione nel mercato degli utensili rivestiti rispetto a quanto accade invece nell'industria metalmeccanica. Un'eccezione, seppure in misura limitata, è rappresentata dai rivestimenti a base di cromo, come il nitruro di cromo (CrN), che forniscono la massima protezione contro l'usura dovuta a processi di corrosione. Questi, infatti, sono riconosciuti come una delle principali cause di usura nella lavorazione del legno, favorendo la successiva usura abrasiva dei fragili prodotti d’ossidazione operata da inclusioni di minerali duri presenti all'interno di materiali a base legnosa, soprattutto prodotti secondari già sottoposti a lavorazioni precedenti. Tuttavia, a causa della relativamente bassa durezza, il CrN fornisce di per sé una scarsa resistenza all'usura abrasiva. Una possibile soluzione consiste nel sostituire rivestimenti monostrato di CrN con rivestimenti multistrato. Ricerche e applicazioni pratiche approfondite hanno dimostrato che la progettazione di rivestimenti multistrato offre numerosi vantaggi rispetto ai rivestimenti a strato singolo, soprattutto se lo spessore degli strati costitutivi è ridotto al regime nanometrico. Tuttavia, la ricerca per lo sviluppo di rivestimenti multistrato mirati a rispondere ai severi requisiti dell'industria del legno è molto limitata. Pertanto, lo scopo di questo progetto di ricerca era di effettuare preliminari studi sulle proprietà protettive dei sistemi di rivestimento PVD multistrato a base di CrN accoppiato con nitruri di indurimento. L’abbinamento di proprietà anticorrosive e migliori caratteristiche meccaniche potrebbero rendere tali sistemi di rivestimento dei potenziali candidati per il rivestimento di utensili da taglio del legno. I nitruri di tungsteno e molibdeno (WN e MoN, rispettivamente) sono stati scelti in quanto già applicati per la realizzazione di sistemi multistrato con altri nitruri, e anche per fornire uno studio comparato su due sistemi che raramente vengono studiati in parallelo nelle stesse condizioni sperimentali. L'obiettivo fondamentale dell'aggiunta di questi materiali aggiuntivi è fornire al CrN una migliore durezza meccanica mantenendo o migliorando l'elevata resistenza alla corrosione, e la letteratura pregressa suggerisce ottime potenzialità di questi materiali come nitruri indurenti.The research activity of this Ph.D. thesis is grounded is founded by the European Interreg ITA-SLO NANOREGION project. The mission of NANOREGION was to provide a scientific support to local enterprises in the region comprehending North-eastern Italy and Slovenia. In such regions the impact of the wood-industry on local economics is relevant. It is well known that the impact of tools replacement has a strong impact on the economics of the wood-working process to maintain the manufacturing standards required to obtain high quality products. Cutting tools are usually coated with hard, refractory thin film coatings to increase their service life and hence increase the manufacture productivity. Nonetheless, owing to the nature of the wood as a workpiece and to the strict technical required specific of wood-machining, the cost-to-benefits ratio of tools coating has so far proved not enough to allow the same market penetration of coated tools that is instead recorded in the metal-working industry. An exception to some extent is represented by Chromium-based coatings such as CrN, which provide the highest protection against corrosive wear, which in turn is recognized as of the main causes of wear in wood-machining, as it favors the subsequent abrasive wear of the brittle oxidation products mediated by hard mineral inclusions within the wood-based materials. Nonetheless, CrN alone is known to provide poor resistance to abrasive wear, due to its relatively low hardness. A large amount of research has demonstrated that the design of multilayer coatings offers several advantages over single-layer coatings, especially if the thickness of the constituent layers is reduced to the nanometric regime. Nonetheless, the research investigating the development of multilayer coatings specifically targeting the strict requirements of the wood industry is very limited. Hence, the purpose of this research process was to investigate preliminary protective properties of multilayer PVD coating systems based on oxidation-protective CrN coupled with hardening nitrides as potential candidate coatings for wood-cutting tools. WN and MoN were chosen due to reported literature on successful coupling of such coatings with other nitrides such as TiN or ZrN and CrN, and because of the limited number of scientific and systematic comparative investigations on these systems. The fundamental aim of the addition of these additional materials is providing CrN with improved mechanical hardness while retaining or improving high corrosion resistance

Production and processing of graphene and related materials

© 2020 The Author(s). We present an overview of the main techniques for production and processing of graphene and related materials (GRMs), as well as the key characterization procedures. We adopt a 'hands-on' approach, providing practical details and procedures as derived from literature as well as from the authors' experience, in order to enable the reader to reproduce the results. Section I is devoted to 'bottom up' approaches, whereby individual constituents are pieced together into more complex structures. We consider graphene nanoribbons (GNRs) produced either by solution processing or by on-surface synthesis in ultra high vacuum (UHV), as well carbon nanomembranes (CNM). Production of a variety of GNRs with tailored band gaps and edge shapes is now possible. CNMs can be tuned in terms of porosity, crystallinity and electronic behaviour. Section II covers 'top down' techniques. These rely on breaking down of a layered precursor, in the graphene case usually natural crystals like graphite or artificially synthesized materials, such as highly oriented pyrolythic graphite, monolayers or few layers (FL) flakes. The main focus of this section is on various exfoliation techniques in a liquid media, either intercalation or liquid phase exfoliation (LPE). The choice of precursor, exfoliation method, medium as well as the control of parameters such as time or temperature are crucial. A definite choice of parameters and conditions yields a particular material with specific properties that makes it more suitable for a targeted application. We cover protocols for the graphitic precursors to graphene oxide (GO). This is an important material for a range of applications in biomedicine, energy storage, nanocomposites, etc. Hummers' and modified Hummers' methods are used to make GO that subsequently can be reduced to obtain reduced graphene oxide (RGO) with a variety of strategies. GO flakes are also employed to prepare three-dimensional (3d) low density structures, such as sponges, foams, hydro- or aerogels. The assembly of flakes into 3d structures can provide improved mechanical properties. Aerogels with a highly open structure, with interconnected hierarchical pores, can enhance the accessibility to the whole surface area, as relevant for a number of applications, such as energy storage. The main recipes to yield graphite intercalation compounds (GICs) are also discussed. GICs are suitable precursors for covalent functionalization of graphene, but can also be used for the synthesis of uncharged graphene in solution. Degradation of the molecules intercalated in GICs can be triggered by high temperature treatment or microwave irradiation, creating a gas pressure surge in graphite and exfoliation. Electrochemical exfoliation by applying a voltage in an electrolyte to a graphite electrode can be tuned by varying precursors, electrolytes and potential. Graphite electrodes can be either negatively or positively intercalated to obtain GICs that are subsequently exfoliated. We also discuss the materials that can be amenable to exfoliation, by employing a theoretical data-mining approach. The exfoliation of LMs usually results in a heterogeneous dispersion of flakes with different lateral size and thickness. This is a critical bottleneck for applications, and hinders the full exploitation of GRMs produced by solution processing. The establishment of procedures to control the morphological properties of exfoliated GRMs, which also need to be industrially scalable, is one of the key needs. Section III deals with the processing of flakes. (Ultra)centrifugation techniques have thus far been the most investigated to sort GRMs following ultrasonication, shear mixing, ball milling, microfluidization, and wet-jet milling. It allows sorting by size and thickness. Inks formulated from GRM dispersions can be printed using a number of processes, from inkjet to screen printing. Each technique has specific rheological requirements, as well as geometrical constraints. The solvent choice is critical, not only for the GRM stability, but also in terms of optimizing printing on different substrates, such as glass, Si, plastic, paper, etc, all with different surface energies. Chemical modifications of such substrates is also a key step. Sections IV-VII are devoted to the growth of GRMs on various substrates and their processing after growth to place them on the surface of choice for specific applications. The substrate for graphene growth is a key determinant of the nature and quality of the resultant film. The lattice mismatch between graphene and substrate influences the resulting crystallinity. Growth on insulators, such as SiO2, typically results in films with small crystallites, whereas growth on the close-packed surfaces of metals yields highly crystalline films. Section IV outlines the growth of graphene on SiC substrates. This satisfies the requirements for electronic applications, with well-defined graphene-substrate interface, low trapped impurities and no need for transfer. It also allows graphene structures and devices to be measured directly on the growth substrate. The flatness of the substrate results in graphene with minimal strain and ripples on large areas, allowing spectroscopies and surface science to be performed. We also discuss the surface engineering by intercalation of the resulting graphene, its integration with Si-wafers and the production of nanostructures with the desired shape, with no need for patterning. Section V deals with chemical vapour deposition (CVD) onto various transition metals and on insulators. Growth on Ni results in graphitized polycrystalline films. While the thickness of these films can be optimized by controlling the deposition parameters, such as the type of hydrocarbon precursor and temperature, it is difficult to attain single layer graphene (SLG) across large areas, owing to the simultaneous nucleation/growth and solution/precipitation mechanisms. The differing characteristics of polycrystalline Ni films facilitate the growth of graphitic layers at different rates, resulting in regions with differing numbers of graphitic layers. High-quality films can be grown on Cu. Cu is available in a variety of shapes and forms, such as foils, bulks, foams, thin films on other materials and powders, making it attractive for industrial production of large area graphene films. The push to use CVD graphene in applications has also triggered a research line for the direct growth on insulators. The quality of the resulting films is lower than possible to date on metals, but enough, in terms of transmittance and resistivity, for many applications as described in section V. Transfer technologies are the focus of section VI. CVD synthesis of graphene on metals and bottom up molecular approaches require SLG to be transferred to the final target substrates. To have technological impact, the advances in production of high-quality large-area CVD graphene must be commensurate with those on transfer and placement on the final substrates. This is a prerequisite for most applications, such as touch panels, anticorrosion coatings, transparent electrodes and gas sensors etc. New strategies have improved the transferred graphene quality, making CVD graphene a feasible option for CMOS foundries. Methods based on complete etching of the metal substrate in suitable etchants, typically iron chloride, ammonium persulfate, or hydrogen chloride although reliable, are time- and resourceconsuming, with damage to graphene and production of metal and etchant residues. Electrochemical delamination in a low-concentration aqueous solution is an alternative. In this case metallic substrates can be reused. Dry transfer is less detrimental for the SLG quality, enabling a deterministic transfer. There is a large range of layered materials (LMs) beyond graphite. Only few of them have been already exfoliated and fully characterized. Section VII deals with the growth of some of these materials. Amongst them, h-BN, transition metal tri- and di-chalcogenides are of paramount importance. The growth of h-BN is at present considered essential for the development of graphene in (opto) electronic applications, as h-BN is ideal as capping layer or substrate. The interesting optical and electronic properties of TMDs also require the development of scalable methods for their production. Large scale growth using chemical/physical vapour deposition or thermal assisted conversion has been thus far limited to a small set, such as h-BN or some TMDs. Heterostructures could also be directly grown