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The discovery of ferroelectricity in polycrystalline thin films of doped HfO2 has reignited the expectations of developing competitive ferroelectric non-volatile memory devices. To date, it is widely accepted that the performance of HfO2-based ferroelectric devices during their life cycle is critically dependent on the presence of point defects as well as structural phase polymorphism, which mainly originates from defects either. The purpose of this review article is to overview the impact of defects in ferroelectric HfO2 on its functional properties and the resulting performance of memory devices. Starting from the brief summary of defects in classical perovskite ferroelectrics, we then introduce the known types of point defects in dielectric HfO2 thin films. Further, we discuss main analytical techniques used to characterize the concentration and distribution of defects in doped ferroelectric HfO2 thin films as well as at their interfaces with electrodes. The main part of the review is devoted to the recent experimental studies reporting the impact of defects in ferroelectric HfO2 structures on the performance of different memory devices. We end up with the summary and perspectives of HfO2-based ferroelectric competitive non-volatile memory devices.

This study probed, through an experimental process, the structural and morphological properties of polycrystalline thin films of lead (II) sulfide (PbS) produced by using the chemical bath depositi...

We report on the magnetic damping properties of polycrystalline $\mathrm{Fe}\text{\ensuremath{-}}\mathrm{V}$ alloy thin films that are deposited at room temperature. By varying the concentration of $\mathrm{V}$ in the alloy, the saturation magnetization can be adjusted from that of $\mathrm{Fe}$ to near zero. We show that exceptionally low values of the damping parameter can be maintained over the majority of this range, with a minimum damping at approximately 15%--20% $\mathrm{V}$ concentration. Such a minimum is qualitatively reproduced with ab initio calculations of the damping parameter, although at a concentration closer to 10% $\mathrm{V}$. The measured intrinsic damping has a minimum value of (1.53 \ifmmode\pm\else\textpm\fi{} 0.08) \ifmmode\times\else\texttimes\fi{} ${10}^{\ensuremath{-}3}$, which is approximately a factor of 3 higher than our calculated value of 0.48 \ifmmode\times\else\texttimes\fi{} ${10}^{\ensuremath{-}3}$. From first-principles theory, we outline the factors that are mainly responsible for the trend of the damping parameter in these alloys. In particular, the band structure and resulting damping mechanism is shown to change at $\mathrm{V}$ concentrations greater than approximately 35% $\mathrm{V}$ content.

The fabrication of organic semiconductor thin films by printing technologies is expected to enable the low-cost production of devices such as flexible display drivers, RF-ID tags, and various chemical/biological sensors. However, large-scale high-speed fabrication of uniform semiconductor thin films with adequate electrical properties for these devices remains a big challenge. Herein, we demonstrate an ultrafast and scalable fabrication of uniform polycrystalline thin films with 100% surface coverage using liquid crystalline semiconductors such as 2-phenyl-7-decyl[1]benzothieno[3,2

Herein, the influence of crystallographic polarity on the properties of ZnO polycrystalline thin films deposited by magnetron sputtering, has been studied. The electrical and optical properties of undoped ZnO and heavily Ga-doped ZnO thin films showed significant differences between Zn polarity and O polarity. The Hall mobility and carrier concentration of the undoped ZnO thin films with Zn polarity were higher than those with O polarity. The ZnO film with Zn polarity showed a dominant near-band-edge emission, while that with O polarity showed relatively intense deep-level emission in the visible wavelength region. It was suggested that acceptor-type defects tend to be formed in the ZnO films with O polarity. The Ga-doped ZnO films deposited on the Zn-polar ZnO layer showed a higher carrier concentration and Hall mobility as compared to deposition on O-polar ZnO. Crystallographic polarity is thus a very important factor for controlling the properties of polycrystalline ZnO-based thin films deposited on glass substrates.

We compare the dopant concentration of polycrystalline Cu(In,Ga)Se2 thin film absorbers derived from Hall and capacitance-voltage measurements. Although both measurements techniques appear to be reliable, dopant concentrations determined by capacitance-voltage analysis are significantly lower and vary with probing depth into the absorber. The doping profiles and differences between both measurement techniques are consistent with Cd in-diffusion from the CdS buffer layer during solar cell fabrication. Different doping profiles obtained after a variation of the CdS deposition process support this scenario.

There has been a longstanding search for top cell materials for Si-based tandems. ZnGeP 2 is one material that could fit this need. It is lattice matched to Si and has the potential for tuning its band gap at fixed lattice constant via cation ordering. In this study, we investigate the effects of growth and annealing conditions on the structure of ZnGeP 2 thin films. Films were deposited amorphous and then annealed ex-situ. Using low anneal temperatures or short anneal times, we were able to kinetically trap the disordered phase. We also found composition to play a role in the degree of ordering in our films. Our findings support the hypothesis that ZnGeP 2 could be implemented as a material with tunable properties at fixed lattice constant through cation ordering.

We investigate the charge transport mechanism in copper phthalocyanine thin films with and without traps. Previously, charge transport in polycrystalline thin films has been widely described by the multiple trapping and release (MTR) model, without emphasizing the origin of the traps. In this work, polycrystalline organic thin films with and without traps have been grown by engineering different growth conditions. We find that the density of interface states at the grain boundaries can decide the mechanism of charge transport in organic thin films and completely different charge transport mechanisms can be observed in thin films with and without traps.

Many technologies deposit thin films on inexpensive substrates, resulting in small grains due to classic nucleation and grain growth theory. For example, state-of-the-art solar cells are made by depositing CdSeTe and CdTe layers on inexpensive glass coated with nanocrystalline transparent conducting oxides (TCOs), like SnO2. Characteristically, the grain size of these films is on the order of the film thickness, i.e. a few microns. CdTe small-grain films have poor electro-optical properties and require CdCl2 passivation which fails to fully passivate grain boundaries, causes carrier compensation, and prevents implementing other II–VI alloys and materials to improve performance. Here, we present a method to increase grain size to 1 mm in CdSexTe1−x thin films deposited on glass/TCO substrates without CdCl2 treatment. The colossal grain growth is driven by mechanisms distinct from classic nucleation, grain growth, and Ostwald ripening and only occurs at low selenium content (x ∼ 0.1). We also demonstrate how these films can serve as templates for subsequent large-grain epitaxy of other compositions like CdTe, again without exposure to CdCl2. The results open new paths for thin film solar cell technology, and thin film devices in general.

International audience; The first direct Barkhausen noise measurement in a ferroelectric thin film is presented. The Barkhausen noise energy loop is reconstructed from the measured Barkhausen noise and is closely related to the classic ferroelectric P vs E hysteresis loop. Grain boundaries act as a dominant ferroelectric domain wall pinning site in a polycrystalline thin film based on the calculated domain wall jump distance using the Barkhausen noise frequency. The technique is promising for the measurement of ferroelectric switching dynamics, and provides a physical insight for improving application performance.

We investigated the electrocaloric (EC) effects in epitaxial Ba0.8Sr0.2TiO3 (BSTO) thin films grown on LaAlO3 and MgO substrates and in BSTO sol-gel thin films grown on Si substrates. We compared the EC effects in two forms of BSTO to confirm whether the giant EC effect recently observed in the polycrystalline thin film is an intrinsic effect or an extrinsic effect exclusively occurring in polycrystalline thin films with nano-sized grains. The EC effect in our BSTO single crystals exhibited a moderate EC temperature change over a broad temperature range. On the other hand, the EC effect in the BSTO sol-gel film was observed over a narrow temperature range with a giant ΔT of about 14 °C. We claim that this giant EC effect is due to the increased saturation field related to the small grain size in the sol-gel thin film.

Polycrystalline thin films of chromium doped tungsten disulphide (WS2) have been deposited onto glass and steel substrates by Aerosol-Assisted Chemical Vapour Deposition (AACVD) using bis(diethyldithiocarbamato)disulfidothioxo tungsten(vi) (WS3L2) and tris(diethyldithiocarbamato) chromium(iii) [Cr(S2CNEt2)3] (CrL3) complexes as precursors in different molar ratios at 450 °C. The deposited films were characterised by p-XRD, SEM, and EDX and Raman spectroscopies. Chromium doping of up to 15 mol% was achieved in WS2 thin films.

CdS polycrystalline thin films have been used as window layer in solar cells; the quality of the CdS-partner plays an important role in the photovoltaic device performance. CdS thin films were deposited using Chemical Bath Deposition (CBD) and photoassisted-CBD technique. The SnO 2 :F substrates used in this work were treated with HCl (0.1 M) and some of themwere annealed in different atmospheres (Ar and O 2 ). The properties of CdS thin films were influenced by the HCl treatment, position and the movement of substrates inside the reactor glass. CdS samples were deposited in areas of 4 cm 2 , 50 cm 2 and 100 cm 2 ; obtaining thin films with thickness of 35 - 300 nm with good crystalline quality and uniform morphology. All samplespresented optical transmittance around of 85 - 91% and average gap energy of 2.5 eV.

A simple and illustrative method of different fast X-ray diffraction sample scans (omega, phi, psi) was applied to the analysis of preferred grain orientation of cubic KTaO3 thin film deposited on highly textured polycrystalline Pt(111) interlayer on Si single crystalline substrate. The material has a tendency to create many different oriented domains — texture components with strongly dominating (100) orientation. By fast subsequent sample scans (ψ-scans) the components with very narrow distribution of orientations were discovered (gradual texture component stripping) and estimated. By comparison with the detector scan taken at low angle of incidence as it is common for thin film analysis it was found that there is also a background of misoriented crystallites in this film together with many texture components. Using only standard single symmetric θ–2θ or asymmetric grazing incidence scans can easily lead to overlooking of important microstructural features.

Thin polycrystalline films based on PbSnAgTe (LATT) compounds on mica-muscovite substrates are obtained. The dependences of conductivity, mobility of current carriers and specific thermoelectric power on temperature for these condensates are investigated. It is established that the mechanisms of transport of carriers on the intergrain boundaries dominate at low temperatures, and at higher temperatures the charge transport is determined by the volume of grain. The predominant scattering mechanism at higher temperatures is scattering on acoustic phonons. В работе получены тонкие поликристаллические пленки на основе соединений PbSnAgTe (LATT) на подложках из слюды-мусковит. Исследована зависимость проводимости, подвижности носителей тока и удельной термоэлектрической мощности от температуры данных конденсатов. Установлено, что механизмы переноса носителей тока на межзеренних границах доминируют при низких темпера- турах, а при более высоких темперетурах перенос заряда определяется объемом зерна. Преобладаю- щим механизмом рассеяния при высоких температурах является рассеяние на акустических фононах. В роботі отримано тонкі полікристалічні плівки на основі сполук PbSnAgTe (LATT) на підкладках зі слюди-мусковіт. Досліджено залежність провідності, рухливості носіїв струму та питомої термоелек- тричної потужності від температури для даних конденсатів. Встановлено, що механізми перенесення носіїв струму на міжзеренних межах домінують при низьких температурах, а при вищих температу- рах перенесення заряду визначається об’ємом зерна. Переважаючим механізмом розсіяння при ви- щих температурах є розсіяння на акустичних фононах.

Microstrain distributions were acquired in functional thin films by high-resolution X-ray microdiffraction measurements, using polycrystalline CuInSe2 thin films as a model system. This technique not only provides spatial resolutions at the submicrometre scale but also allows for analysis of thin films buried within a complete solar-cell stack. The microstrain values within individual CuInSe2 grains were determined to be of the order of 10−4. These values confirmed corresponding microstrain distribution maps obtained on the same CuInSe2 layer by electron backscatter diffraction and Raman microspectroscopy.

Cu(In1−xGax)Se2 (CIGS) polycrystalline thin films were prepared by the two-stage method for two different precursors corresponding to the sequences CuGa/CuIn/CuGa and CuGa/In/Cu/CuGa, respectively. In order to obtain the required Ga-grading profile, co-evaporation of GaxSe for incorporation of gallium into CIGS was used. Experimental results show that CIGS films were prepared by the proposed process with a ‘notch’ Ga-graded distribution, and the surface morphologies of the films after gallium incorporation were significantly changed compared with that of the as-selenized films, and the process was found to have little effect on the film structure. No new impurity phases have been found. The main XRD peaks shows a slight shift to higher diffraction angles with increasing Ga content, which could be attributed to Ga atoms substituting for In atoms in the chalcopyrite structure. The result of the present work implied that the proposed process was feasible for forming a ‘notch’ Ga-graded structure in CIGS thin films.

Ferroelectric PbMg1/3Nb2/3O3–0.33PbTiO3 (PMN–0.33PT) polycrystalline thin film near MPB was grown on Ir with LaNiO3 buffer layer by pulsed laser deposition technology. Piezoresponse force microscopy (PFM) was employed to investigate the role of grain boundary on the domains formation and their local physical properties in PMN–PT thin film. Unusual piezoresponse behaviors were firstly observed across the grain boundary of PMN–PT thin film via PFM. Such abnormal phenomenon is ascribed to the structural incompatibility-induced local stress across the grain boundary, which gives a deep influence on the local imprint behavior of PMN–PT thin film.

We investigate, via both experiment and simulation, the effects of self-shadowing on the growth of faceted polycrystalline thin films. Faceted aluminum thin films were sputtered and the anomalous scaling behaviour of their surfaces was characterized. To understand the causes of this anomalous behavior, growth of faceted thin films was simulated by coupling a level set construction to a ballistic deposition model. The angular distribution function of deposition flux was varied to control the degree of self-shadowing. We show how differing degrees of self-shadowing strongly modify film surface morphologies and compare these results with experimental findings.

International audience; This article reports the first investigations of CuIn1-xGaxSe2 (CIGSe) polycrystalline thin films by means of atom probe tomography. Attention is focused on the distribution of Na atoms within the films. Both Na-containing and Na-free CIGSe thin films have been investigated. When Na is available during the CIGSe coevaporation, it is observed to be mainly segregated at the grain boundaries of the films; however, it is also detected within the grains of CIGSe at very low concentration.

Analytical solutions to Fick’s second law of diffusion have been simultaneously derived without the restrictions of parabolic profiles along the x-axis in grain boundaries and expressed in a series for both grain interior and grain boundary diffusing through a polycrystalline thin film. The analysis takes segregation of diffusion species at grain boundaries into account. The analytic solutions lead to the concentration profiles in the grain interior and in the grain boundary, to the average-integrated amount of diffusion species at the exit surface, and to the time lag, which can be technologically used for depth profile studies and kinetic accumulation measurements.

Performing a completein situmechanical property analysis of polycrystalline thin films using X-ray diffraction is time consuming with most standard diffraction beamlines at synchrotron facilities and not realistic with laboratory diffractometers. Two-dimensional detection is shown to enable relatively fast and reliable X-ray strain measurements duringin situtensile testing of gold films deposited on polyimide substrates. Advantages and drawbacks in the use of two-dimensional detectors for this type of analysis are discussed for two commonly used geometries: reflection and transmission.

The growth mechanism, microstructure, and crystal structure of the polycrystalline nBi2Te3 thin films with thicknesses d = 15 – 350 nm, prepared by thermal evaporation in vacuum onto glass substrates, were studied. Bismuth telluride with Te excess was used as the initial material for the thin film preparation. The thin film characterization was performed using X-ray diffraction, X-ray photoelectron spectroscopy, energy-dispersive X-ray spectroscopy, scan electron microscopy, and electron force microscopy. It was established that the chemical composition of the prepared films corresponded rather well to the starting material composition and the films did not contain any phases apart from Bi2Te3. It was shown that the grain size and the film roughness increased with increasing film thickness. The preferential growth direction changed from [00l] to [015] under increasing d. The X-ray photoelectron spectroscopy studies showed that the thickness of the oxidized surface layer did not exceed 1.5 – 2.0 nm and practically did not change in the process of aging at room temperature, which is in agreement with the results reported earlier for single crystals. The obtained data show that using simple and inexpensive method of thermal evaporation in vacuum and appropriate technological parameters, one can grow n-Bi2Te3 thin films of a sufficiently high quality. Телурид вісмуту (Bi 2 Te 3 ) є ефективним термоелектричним матеріалом, і виготовлення тонких плівок Bi 2 Te 3 з хорошими термоелектричними властивостями є необхідною умовою для реалізації потенціалу цих матеріалів у застосуванні мікропристроїв. Контрольоване осадження вмісту та термічна обробка з низьким негативним впливом є двома основними проблемами при виготовленні високоефективних тонких плівок. У цьому дослідженні стехіометричний Bi 2 Te 3тонкі плівки були успішно виготовлені за допомогою двоетапного процесу термічної пари з одним джерелом випаровування. Потім швидкий термічний процес, який міг уникнути втрати компонентів, був використаний для подальшого покращення кристалічності та термоелектричних властивостей тонких плівок. Коефіцієнт Зеєбека тонких плівок Bi 2 Te 3 явно збільшився після швидкої термічної обробки, що призвело до підвищення коефіцієнта потужності та хорошої гнучкості. Такі тонкі плівки демонстрували низьку теплопровідність через їх нанорозмірні зерна, що призвело до високого ZT гнучких тонких плівок Bi 2 Te 3

Polycrystalline thin films were synthesized on Si(100) substrates using sol-gel method and the effects of Mn substitution on the structural, magnetic, and magnetotransport properties were analyzed. X-ray diffraction revealed that cubic structure is maintained up to x

Polycrystalline thin film CuInS 2 -on-Cu-tape (CISCuT) solar cells were studied using deep level transient spectroscopy (DLTS). Temperature scans between 5 and 320 K reveal a large positive peak and a smaller negative peak. The positive peak is analysed using isothermal DLTS measurements which indicates a deep level defect with a very high concentration, contributing significantly to the carrier concentration at room temperature. The negative peak can be related to an energy barrier, possibly located at the back contact. We find an estimated barrier height of 164 meV. Electrical injection DLTS and optical injection DLTS measurements were also carried out.

A micromechano-optical material is rapidly and reversibly switched between distinct states of reflectance by simply stretching and relaxing the hybrid structure. The material is fabricated and controlled by leveraging the ability of soft elastic substrates to regulate the growth and morphological evolution of a chemically deposited polycrystalline thin film.

The structure and characteristics of CdTe thin films are closely dependent on the whole deposition process in close-space sublimation (CSS). The physical mechanism of CSS was analyzed and the temperature distribution in CSS system was measured, and the influences of the increasing-temperature process and pressure on the preliminary nucleus creation were studied. The results indicate: the samples deposited at different pressures have a cubical structure of CdTe and the diffraction peaks of CdS and SnO2: F. As the atmosphere pressure increases, the crystal size of CdTe decreases, the rate of the transparency of the thin film decreases and the absorption side moves towards the short-wave direction. After a 4-minute depositing process with a substrate temperature of 500°C and a source temperature of 620°C, the polycrystalline thin films can be made, so the production of high-quality integrated cell with SnO2: F/CdS/CdTe/Au structure is hopeful.

In order to further decrease the fabrication cost, a technology of close-spaced sublimation under Ar–O 2 mixture atmosphere has been studied. A deposition method of CdTe thin films on smooth glass substrates has been developed. The structural characteristics of CdTe films, which are deposited on glass substrate and CdS/SnO 2 :F/glass substrate, have been compared. The effects of oxygen partial pressure on the structure and characteristics have been investigated and the preferred orientation was quantificationally studied, which shows that there are the same structures of CdTe thin films on both kinds of substrates, if these films are deposited in an appropriate close-spaced sublimation process. Then the optical and electrical properties of CdTe films on glass substrates are studied, and the effects of post-treatment on the properties are observed. These results have been used to prepare CdS/CdTe/ZnTe:Cu solar cells.

Cubic CdS (β-CdS) polycrystalline thin films were prepared on glass substrates by chemical synthesis at 80 °C. Samples were subjected to thermal treatments (TT) in the range of temperatures (T) 180 – 500 °C during 30 hours in different ambients. Annealing in air and in H2 produces in CdS larger lattice parameter enlargements (≤2.5 %) when T of TT increases up to T ≤ 500 °C. Whereas, annealing in Ar + S2 and vacuum provokes intermediate (≤1.2 %) and smaller (≤0.9 %) maxima values of the lattice parameter increments, respectively. Energy band gap (Eg) as a function of T of TT and as a function of the lattice parameter has been also studied where it was observed that Eg behaves in very different manners depending on the ambient chosen for annealing. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

An atomistic Monte Carlo code to simulate the deposition and annealing of three-dimensional polycrystalline thin films is presented. Atoms impinge on the substrate with selected angular distributions, and grains are nucleated with different crystalline orientations, defined by the tilt and rotation angles. Grain boundaries appear naturally when the islands coalesce, and can migrate during both deposition and annealing simulations. In this work we present simulations of aluminum films. We examine the influence of the temperature, deposition rate, and adhesion to the substrate on the morphology of polycrystalline thin films. The simulations provide insight into the dominant microscopic mechanisms that drive the structure evolution during thin film processing.

Substitution of Fe with Co resulted in lower values of the saturation magnetostriction and higher Curie temperatures of TbDyFeCo system. In this study the magnetic and magnetostrictive properties of amorphous and polycrystalline thin films with composition (Tb0.3Dy0.7)40Fe60-xCox (x=10, 25, 30, 33) have been investigated in order to analyze the effect of Co substitution on the magnetic and magnetostrictive properties of (Tb0.3Dy0.7)40Fe60. X-ray diffraction studies revealed that all crystalline compositions retained the C-15 cubic Laves phase structure. Substitution of Fe with Co resulted in lower values of the saturation magnetostriction and higher Curie temperatures of both amorphous and crystalline films.

The dependence of effective interdiffusion coefficients versus the misfit of the parameters of crystalline lattices of film and substrate for double polycrystalline thin films of Pd–Ag and Pd–Au systems has been studied with the use of X-ray analysis. Silver, gold, Pd–Ag and Pd–Au alloys were used as substrates. Palladium was used as a film. The magnitude of the misfit was changed with the use of a Pd concentration change in the substrate. It was established that the decrease of misfit from 4.9 to 0.94% leads to subsidence of the effective diffusion coefficients in Pd film more than several orders of magnitudes.

The enhancement of the photochemical deposition (PCD) of polycrystalline thin films of CdS with the addition of EDTA has been established. The effect of concentration of EDTA on the surface coverage of the film has been studied using optical microscope.

Lead-free (Bi 0.5 Na 0.5 ) 1 − x Ba x TiO 3 (BNBT) thin films with compositions at x = 0.055, 0.100, and 0.150 were prepared by chemical solution deposition on Pt/TiO 2 /SiO 2 /(100)Si substrates. The dielectric behavior of the films was studied, and the ferroelectric-antiferroelectric phase transition observed was used to situate the morphotropic phase boundary (MPB) for compositions with x ~ 0.100 (BNBT-10), a value that differs from that reported for bulk materials (BNBT-5.5). Extrinsic effects derived from the thin-film configuration (e.g., microstrains, residual stresses) may be responsible for the shift of the MPB. Consequently, the dielectric permittivity is significantly improved for this composition, showing the best ferroelectric response obtained up to now for films of the BNBT system (P r = 13.0 μC/cm 2 , E c = 70 kV/cm).

Colloidal suspensions of nanoparticles are increasingly employed in the fabrication process of electronic devices using inkjet-printing technology and a consecutive thermal treatment. The evolution of internal stresses during the conversion of silver nanoparticle-based ink into a metallic thin-film by a thermal sintering process has been investigated by in-situ XRD using the sin2ψ method. Despite the CTE mismatch at the film/substrate interface, the residual stress in silver films (below 70 MPa) remains lower than in conventional PVD thin-films, as a result of the remaining porosity. A Warren-Averbach analysis further showed that the crystallite growth is associated with a minimization of the twin fault density and the elastic microstrain energy above 150°C. A stabilization of the microstructure and internal stress is observed above 300°C. Inkjetprinting technology thus appears as a good alternative to conventional metallization techniques and offers significant opportunities asset for interconnect and electronic packaging. cop. (2014) Trans Tech Publications, Switzerland. 'Conseil General de l'Aube'; Conseil National de la Recherche Scientifique (CNRS); et al; Grand Troyes; Proto Manufacturing; Region Champagne-Ardenne

Magnetoconductivity (MC), Δσ(Β), and Hall coefficient, RH (B), measurements have been performed in polycrystalline thin films of Bi(15nm), Bi(10nm)/Co(1nm)/Bi(10nm) trilayer and [Co(0.7nm)/Bi(2nm)]10 multilayer, grown by magnetron scattering. The temperature dependence of RH (B) curves reveal the existence of a second conduction channel below 250K, that can be assigned to surface states. MC measurements between ±0.4T show at 5K an interplay between weak-antilocalization (WAL) in Bi and Bi/Co/Bi films and weal-localization (WL) in [Co/Bi]10 multilayer.

The fundamental mechanisms behind the generation of compressive stresses in polycrystalline thin films, the effects of pulsed deposition fluxes on the dynamics of the early growth stages as well as ...

A brief overview of the texture-residual stress relations is presented together with some simulations, including both the calculation of the X-ray Elastic Constants (XECs) and the modelling of a through-thickness planar residual stress in fibre-textured thin films. Advantages and limits of the X-ray Residual. Stress Analysis (XRSA) are discussed, also in relation to the underlying hypotheses. Thin film homogeneity, in particular, can be a severe limitation to describe real systems.

Thin films of ZnO were deposited by thermal decomposition of Zn(C 5 H 7 O 2 ) 2 on semiconductor substrate, n-type silicon, p-type InP and also on transparent glass substrate. The obtained ZnO/Si and ZnO/InP heterostructures were investigated for optical properties by spectrophotometry and surface morphology by AFM. The measured values of optoelectrical parameters in the visible spectral range and the lateral photovoltage characteristics demonstrate the possibility of using ZnO/n-Si and ZnO/p-InP heterojunctions for photodetection and photovoltaic devices applications.

In this paper, the effects of grain orientation on preferred abnormal grain growth in HCP-polycrystalline thin films have been analysed with respect to strain energy. The calculated results showed that Chkl, the average values of the orientation factor, decreased with increase of 1 for the same h and k and increased with increase of h or/and k for constant 1. Where (hkl) denoted a particular grain orientation, that is, the grains with (hkl) planes oriented parallel to the film surface. This is preannounced that, considering the strain energy solely, the grains with higher 1 and lower h and k should be favorable in HCP-polycrystalline thin films on rigid substrates after annealing.

A review of the current understanding of the effect of interfaces on the intrinsic stresses in polycrystalline thin films is given. Special attention is paid to the measurement, modeling and application of surface and interface stresses. Mechanisms for generating the compressive and tensile components of the intrinsic stress are assessed. Prospects for future research are presented.

Ultraviolet random lasing action with a tunable wavelength between 375 and 400 nm has been realized from highly disordered Zn 1– x Mg x O (for 0≤ x ≤0.3) polycrystalline thin films deposited on silicon substrates by the filtered cathodic vacuum arc technique. The emission energy can be continuously tuned within the ranges of 3.10–3.31 eV, while the corresponding lasing threshold remained relatively uniform.

Pb(Zr1-xTix)O3 (PZT) polycrystalline thin films were prepared by sol–gel and pulsed laser deposition techniques on Pt/Ti/SiO2/Si (Pt) and SrRuO3/LaAlO3 (SRO/LAO) substrates. Infrared reflectivity spectroscopy with oblique (45°) light incidence revealed both the 3LO (688 cm-1) phonon lineshape asymmetry decrease with increasing in thickness and the thinner, disordered boundary layer at the SRO/PZT interface independently of the film preparation method. The fatigue properties of PZT films were studied for various crystallographic orientations. It was observed that in the 52/48 PZT/SRO/LAO film, when the field is applied along the (001) direction, excellent fatigue resistance is obtained.

CdS polycrystalline thin films prepared onto glass substrates by the chemical bath deposition method at 80°C showed cubic crystalline structure (β-CdS). Upon thermal annealing in Ar + S2 flux at different temperatures in the range 200–510°C, the crystalline structure evolution of layers from the cubic modification (as-grown sample) to hexagonal phase (annealed at highest temperature samples) has been observed. At around 300°C the critical point of the phase transition has been experimentally determined to occur. Raman spectroscopy measurements were carried out at room temperature for as-grown and annealed layers. The A1(LO) + E1(LO) modes at 305 cm−1 and replicas appear for as-grown and annealed samples. The E1(TO) and the A1(TO) modes were also observed. A classic simple approach is proposed in order to explain the presence of the TO modes.

Nanophase γ-Gd2S3 polycrystalline thin films were deposited by a so-called asynchronous pulse ultrasonic spray pyrolysis method on glass substrates at relatively low temperature without any complexing agent. The films were characterized by X-ray diffraction, scanning electron microscopy and Raman spectrum. The technical conditions leading to optimal performance were identified. An appropriate ratio of pulse time to interval time between pulses is found to be necessary for obtaining homogeneous and uniform nanostructural γ-Gd2S3 thin films.

Well-crystallized polycrystalline thin films of cubic barium titanate (BaTiO3) have been synthesized on Ti-covered Si substrates by exposing the substrates to a Ba(OH)2 aqueous solution at 160 °C and a low pressure less than 1 MPa. It was presumed that the film formation of BaTiO3 involved a dissolution-crystallization mechanism, which provides an attractive approach to produce other titanate films and powders. Also, we have used for the first time this hydrothermal technique to deposit epitaxial (001)-textured PbTiO3 thin films on SrTiO3(100) substrates.