Highly stable and conformal Ti-organic thin films from sustainable precursors atomic/molecular layer deposition towards green energy applications.

Thin-film deposition using sustainable precursors is required for various next-generation green energy applications. Here we report two atomic/molecular layer deposition processes for appreciably stable and conformal Ti-organic thin films and TiO:organic superlattices with potential in battery, photocatalysis and thermoelectric applications. These processes are based on the safe and sustainable titanium isopropoxide as the titanium precursor.

Chemical Bonding and Crystal Structure Schemes in Atomic/Molecular Layer Deposited Fe-Terephthalate Thin Films.

Advanced deposition routes are vital for the growth of functional metal-organic thin films. The gas-phase atomic/molecular layer deposition (ALD/MLD) technique provides solvent-free and uniform nanoscale thin films with unprecedented thickness control and allows straightforward device integration. Most excitingly, the ALD/MLD technique can enable the in situ growth of novel crystalline metal-organic materials.

Conformal Zn-Benzene Dithiol Thin Films for Temperature-Sensitive Electronics Grown via Industry-Feasible Atomic/Molecular Layer Deposition Technique.

The atomic/molecular layer deposition (ALD/MLD) technique combining both inorganic and organic precursors is strongly emerging as a unique tool to design exciting new functional metal-organic thin-film materials. Here, this method is demonstrated to work even at low deposition temperatures and can produce highly stable and conformal thin films, fulfilling the indispensable prerequisites of today's 3D microelectronics and other potential industrial applications. This new ALD/MLD process is developed for Zn-organic thin films grown from non-pyrophoric bis-3-(N,N-dimethylamino)propyl zinc [Zn(DMP)] and 1,4-benzene dithiol (BDT) precursors.

Conformal High-Aspect-Ratio Solid Electrolyte Thin Films for Li-Ion Batteries by Atomic Layer Deposition.

Lithium phosphorus oxynitride (LiPON) is a state-of-the-art solid electrolyte material for thin-film microbatteries. These applications require conformal thin films on challenging 3D surface structures, and among the advanced thin-film deposition techniques, atomic layer deposition (ALD) is believed to stand out in terms of producing appreciably conformal thin films. Here we quantify the conformality (i.

Centrosymmetric to non-centrosymmetric transition in the CaMnTiO double perovskite system studied through structural analysis and dielectric properties.

We have used high-pressure synthesis to synthesize samples of CaMnTiO double perovskite, where varies between 0.2 and 1. The synthesized materials were structurally characterized with powder X-ray diffraction (XRD).

Atomic/molecular layer deposition of europium-organic thin films on nanoplasmonic structures towards FRET-based applications.

We present a novel atomic/molecular layer deposition (ALD/MLD) process for europium-organic thin films based on Eu(thd) and 2-hydroxyquinoline-4-carboxylic acid (HQA) precursors. The process yields with appreciably high growth rate luminescent Eu-HQA thin films in which the organic HQA component acts as a sensitizer for the red Eu luminescence, extending the excitation wavelength range up to 400 nm. We moreover deposit these films on nanoplasmonic structures to achieve a twentyfold enhanced emission intensity.

Excitation Wavelength Engineering through Organic Linker Choice in Luminescent Atomic/Molecular Layer Deposited Lanthanide-Organic Thin Films.

We demonstrate multiple roles for the organic linker in luminescent lanthanide-organic thin films grown with the strongly emerging atomic/molecular layer deposition technique. Besides rendering the hybrid thin film mechanically flexible and keeping the lanthanide nodes at a distance adequate to avoid concentration quenching, the organic moieties can act as efficient sensitizers for the lanthanide luminescence. We investigate six different aromatic organic precursors in combination with Eu ions to reveal that by introducing different nitrogen species within the aromatic ring, it is possible to extend the excitation wavelength area from the UV range to the visible range.

Auditory Steady-State Response and Hearing Impairment in Survivors of Childhood Bacterial Meningitis in Luanda, Angola.

Survivors of childhood bacterial meningitis (BM) often develop hearing impairment (HI). In low- and middle-income countries (LMICs), BM continues to be a significant cause of hearing disability. We assessed hearing among BM survivors using auditory steady-state responses (ASSR), providing frequency-specific estimated audiograms, and examined whether ASSR would provide a greater understanding of BM-induced HI.

Nanoporous Metal-Organic Framework Thin Films Prepared Directly from Gaseous Precursors by Atomic and Molecular Layer Deposition: Implications for Microelectronics.

Atomic/molecular layer deposition (ALD/MLD) allows for the direct gas-phase synthesis of crystalline metal-organic framework (MOF) thin films. Here, we show for the first time using krypton and methanol physisorption measurements that ALD/MLD-fabricated copper 1,4-benzenedicarboxylate (Cu-BDC) ultrathin films possess accessible porosity matching that of the corresponding bulk MOF.

Nonclassical Crystallization and Core-Shell Structure Formation of Ibuprofen from Binary Solvent Solutions.

Liquid-liquidphase separation (LLPS) or dense liquid intermediates during the crystallization of pharmaceutical molecules is common; however, their role in alternative nucleation mechanisms is less understood. Herein, we report the formation of a dense liquid intermediate followed by a core-shell structure of ibuprofen crystals via nonclassical crystallization. The Raman and SAXS results of the dense phase uncover the molecular structural ordering and its role in nucleation.

SnO deposition water based ALD employing tin(II) formamidinate: precursor characterization and process development.

Tin monoxide (SnO) is a promising oxide semiconductor which is appealing for a wide range of applications from channel materials in p-type field effect transistors (FET) to electrode materials searched for next-generation batteries. For the controlled growth of SnO films at low temperatures, atomic layer deposition (ALD) is employed in this study, where the choice of the precursor plays a significant role. A comparative thermal evaluation of four different amidinate-based tin(II) precursors and the influence of the ligand sphere on their physicochemical properties revealed that bis(,'-diisopropylformamidinato tin(II) (1) possesses the required volatility, good thermal stability and sufficient reactivity towards water, to be implemented as the ALD precursor.

Low-temperature ALD/MLD growth of alucone and zincone thin films from non-pyrophoric precursors.

The combined atomic/molecular layer deposition (ALD/MLD) technique is emerging as a state-of-the-art synthesis route for new metal-organic thin-film materials with a multitude of properties by combining those of the inorganic and the organic material. A major part of the studies so far reported have focused on aluminum or zinc alkyls, so-called alucone and zincone films, typically grown from trimethyl aluminum (TMA) or diethyl zinc (DEZ) as the metal-bearing precursor, and a simple aliphatic bi-functional alcohol molecule such as ethylene glycol (EG) as the organic precursor. However, these common precursors possess certain disadvantages: both TMA and DEZ are pyrophoric, DEZ being additionally thermally unstable, while EG has a strong tendency for various unideal reaction modes.

Atomic Layer Deposition of Intermetallic FeZn Thin Films from Diethyl Zinc.

We present a new type of atomic layer deposition (ALD) process for intermetallic thin films, where diethyl zinc (DEZ) serves as a coreactant. In our proof-of-concept study, FeCl is used as the second precursor. The FeCl + DEZ process yields in situ crystalline FeZn thin films, where the elemental purity and Fe/Zn ratio are confirmed by time-of-flight elastic recoil detection analysis (TOF-ERDA), Rutherford backscattering spectrometry (RBS), atomic absorption spectroscopy (AAS), and energy-dispersive X-ray spectroscopy (EDX) analyses.

Atomic/molecular layer deposition of cerium(III) hybrid thin films using rigid organic precursors.

An atomic/molecular layer deposition (ALD/MLD) process for the fabrication of cerium-based metal-organic hybrid films is demonstrated for the first time. The highly reactive cerium(III) guanidinate precursor [Ce(dpdmg)] was employed in combination with organic precursors composed of rigid backbones, terephthalic acid (TPA) and hydroquinone (HQ) for the growth of the respective hybrid films. Growth rates of the films as high as 5.

Gas-phase deposition of di- and tetra-lithium salts of 2,5-dihydroxyterephthalic acid.

Thin films of two ambipolar lithium-organic electrode materials, LiDHTP and LiDHTP, are grown from gaseous precursors, Li(thd) (tetramethyl heptanedione) and DHTP (dihydroxyterephthalic acid). These precursors are pulsed into the reactor in a sequential manner like in atomic/molecular layer deposition, but the reaction product, the di- or the tetra-lithium salt, is controlled by adjusting the precursor pulse lengths.

Role of Anionic Backbone in NHC-Stabilized Coinage Metal Complexes: New Precursors for Atomic Layer Deposition.

Cu and Ag precursors that are volatile, reactive, and thermally stable are currently of high interest for their application in atomic-layer deposition (ALD) of thin metal films. In pursuit of new precursors for coinage metals, namely Cu and Ag, a series of new N-heterocyclic carbene (NHC)-based Cu and Ag complexes were synthesized. Modifications in the substitution pattern of diketonate-based anionic backbones led to five monomeric Cu complexes and four closely related Ag complexes with the general formula [M( NHC)(R)] (M=Cu, Ag; NHC=1,3-di-tert-butyl-imidazolin-2-ylidene; R=diketonate).

Atomic and Molecular Layer Deposition of Alkali Metal Based Thin Films.

Atomic layer deposition (ALD) is the fastest growing thin-film technology in microelectronics, but it is also recognized as a promising fabrication strategy for various alkali-metal-based thin films in emerging energy technologies, the spearhead application being the Li-ion battery. Since the pioneering work in 2009 for Li-containing thin films, the field has been rapidly growing and also widened from lithium to other alkali metals. Moreover, alkali-metal-based metal-organic thin films have been successfully grown by combining molecular layer deposition (MLD) cycles of the organic molecules with the ALD cycles of the alkali metal precursor.

Role of terminal groups in aromatic molecules on the growth of AlO-based hybrid materials.

Hybrid materials composed of organic and inorganic components offer the opportunity to develop interesting materials with well-controlled properties. Molecular Layer Deposition (MLD) is a suitable thin film deposition technique for the controlled growth of thin, conformal hybrid films. Despite the great interest in these materials, a detailed understanding of the atomistic mechanism of MLD film growth is still lacking.

Atomic/molecular layer deposition of Ni-terephthalate thin films.

Atomic/molecular layer deposition (ALD/MLD) is currently strongly emerging as an intriguing route for novel metal-organic thin-film materials. This approach already covers a variety of metal and organic components, and potential applications related to sustainable energy technologies. Among the 3d metal components, nickel has remained unexplored so far.

Health-related Quality of Life After Childhood Bacterial Meningitis.

Background: Survivors of bacterial meningitis (BM) often suffer from impaired quality of life that stems from disabling sequelae. The authors aimed to estimate health-related quality of life (HRQOL) and the influence of neurologic and audiologic sequelae among pediatric BM survivors.

Methods: Survivors of 2 BM treatment trials at Luanda Children's Hospital, Angola were evaluated for severity of disability via the modified Glasgow Outcome Scale, which considers neurologic and audiologic sequelae.

Photoactive Thin-Film Structures of Curcumin, TiO and ZnO.

Curcumin is known as a biologically active compound and a possible antimicrobial agent. Here, we combine it with TiO and ZnO semiconductors, known for their photocatalytic properties, with an eye towards synergistic photo-harvesting and/or antimicrobial effects. We deposit different nanoscale multi-layer structures of curcumin, TiO and ZnO, by combining the solution-based spin-coating (S-C) technique and the gas-phase atomic layer deposition (ALD) and molecular layer deposition (MLD) thin-film techniques.

Thermal Transport and Thermoelectric Effect in Composites of Alumina and Graphene-Augmented Alumina Nanofibers.

The remarkable tunability of 2D carbon structures combined with their non-toxicity renders them interesting candidates for thermoelectric applications. Despite some limitations related to their high thermal conductivity and low Seebeck coefficients, several other unique properties of the graphene-like structures could out-weight these weaknesses in some applications. In this study, hybrid structures of alumina ceramics and graphene encapsulated alumina nanofibers are processed by spark plasma sintering to exploit advantages of thermoelectric properties of graphene and high stiffness of alumina.

Functionally Graded Tunable Microwave Absorber with Graphene-Augmented Alumina Nanofibers.

Graphene is currently attracting attention for radiation absorption particularly at gigahertz and terahertz frequencies. In this work, composites formed by graphene-augmented γ-AlO nanofibers embedded into the α-AlO matrix are tested for X-band absorption efficiency. Composites with 15 and 25 wt % of graphene fillers with shielding effectiveness (SE) of 38 and 45 dB, respectively, show a high reflection coefficient, while around the electrical percolation threshold (∼1 wt %), an SE of 10 dB was achieved.