MBE-grown NiyMg1-yO and ZnxMg1-xO Thin Films for Deep Ultraviolet Optoelectronic Applications

2009 ◽  
Vol 1201 ◽  
Author(s):  
Jeremy West Mares ◽  
Ryan Casey Boutwell ◽  
Matthew Thomas Falanga ◽  
Amber Scheurer ◽  
Winston Vaughan Schoenfeld
Keyword(s):  
Thin Films ◽  
Electrical Characterization ◽  
Heteroepitaxial Growth ◽  
X Ray Diffraction ◽  
Force Microscopy ◽  
Lattice Constants ◽  
Atomic Force ◽  
Zn Concentration ◽  
Deep Ultraviolet ◽  
Lattice Matched

AbstractWe report on the heteroepitaxial growth of high-quality single crystal cubic ZnxMg1-xO and NiyMg1-yO thin films by radio frequency oxygen plasma-assisted molecular beam epitaxy (RF-MBE). Film compositions over the ranges x = 0 to x = 0.65 and y = 0 to y = 1 have been grown on lattice-matched MgO (100) and characterized optically, morphologically, compositionally, and electrically. Both of these ternary materials are shown to have bandgaps which vary directly as a function of transition metal (Ni or Zn) concentration. Optical transmission measurements of NiyMg1-yO show the bandgap to shift continuously over the approximate range 3.5 eV (for NiO) to 4.81 eV (for y=0.075). Similarly, the bandgap of cubic ZnxMg1-xO is shifted from about 4.9 eV (for x = 0.65) to 6.25 eV (for x=0.12). Films exhibit good morphological quality and typical roughness of NiyMg1-yO films is 5 Å while that of ZnxMg1-xO is less than 15 Å, as measured by atomic force microscopy (AFM). X-ray diffraction (XRD) is employed to confirm crystal orientation and to determine the films' lattice constants. Film compositions are interrogated by Rutherford Backscattering (RBS) and electrical characterization is made by room-temperature Hall measurements.

Growth of heteroepitaxial GaSb thin films on Si(100) substrates

2004 ◽  
Vol 19 (8) ◽  
pp. 2315-2321 ◽  
Author(s):  
Thang Nguyen ◽  
Walter Varhue ◽  
Edward Adams ◽  
Mark Lavoie ◽  
Stephen Mongeon
Keyword(s):  
Thin Films ◽  
Film Thickness ◽  
Lattice Mismatch ◽  
Stacking Faults ◽  
Heteroepitaxial Growth ◽  
X Ray Diffraction ◽  
Force Microscopy ◽  
Radio Frequency Sputtering ◽  
Atomic Force ◽  
Transmission Electron

The heteroepitaxial growth of GaSb thin films on Si(100) and GaAs(100) substrates is presented. The growth technique involves the use of atomic Ga and Sb species, which are provided by thermal effusion and radio frequency sputtering, respectively. The crystalline quality of the heteroepitaxial GaSb film on the Si substrate is high despite the larger lattice mismatch. Epitaxial quality is determined by high-resolution x-ray diffraction and Rutherford backscatter spectrometry channeling. Atomic-force microscopy is used to monitor the evolution of surface morphology with increasing film thickness. Transmission electron microscopy shows the formation of stacking faults at the Si/GaSb interface and their eventual annihilation with increasing GaSb film thickness. Annihilation of stacking faults occurs when two next-neighbor mounds meet during the overgrowth of a common adjacent mound.

Semiconducting YBCO Thin Films for Uncooled Terahertz Imagers

2008 ◽  
Vol 587-588 ◽  
pp. 273-277 ◽  
Author(s):  
Mattia Longhin ◽  
Alain J. Kreisler ◽  
Annick F. Dégardin
Keyword(s):  
Thin Films ◽  
Near Infrared ◽  
Electrical Characterization ◽  
X Ray Diffraction ◽  
Sensing Element ◽  
Force Microscopy ◽  
Research Activities ◽  
Atomic Force ◽  
Ybco Thin Films ◽  
Wide Range

The terahertz domain (500 GHz - 5 THz) has been object of unceasing research activities, due to the wide range of conceivable applications in these fields. This study focuses on the development of semiconducting YBa2Cu3O6+x (YBCO) thin films to be used as sensitive elements on future uncooled terahertz imagers working on a thermal principle. YBCO thin films have been hollow-cathode sputtered on MgO single-crystals under different conditions. Electrical and structural characterizations have then been carried out. The resistivity of the thin films and the temperature coefficient of resistance (TCR) have been determined. X-ray diffraction and atomic force microscopy analyses have then been performed. If compared with materials currently used as sensing element in commercial near-infrared imagers, electrical characterization shows values of the TCR comparable to amorphous silicon and almost two times better than VOx-compounds.

Heteroepitaxial Growth of Epitaxial C60-Thin Films on Mica(001)

1994 ◽  
Vol 359 ◽  
Author(s):  
S. Henke ◽  
K.H. Thürer ◽  
S. Geier ◽  
B. Rauschenbach ◽  
B. Stritzker
Keyword(s):  
Thin Films ◽  
Film Thickness ◽  
Substrate Temperature ◽  
Room Temperature ◽  
Heteroepitaxial Growth ◽  
X Ray Diffraction ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Substrate Temperatures

ABSTRACTOn mica(001) thin C60-films are deposited by thermal evaporation at substrate temperatures from room temperature up to 225°C. The dependence of the structure and the epitaxial alignment of the thin C60-films on mica(001) on the substrate temperature and the film thickness up to 1.3 μm at a well-defined deposition rate (0.008 nm/s) is investigated by atomic force microscopy and X-ray diffraction. The shape and the size of the C60-islands, which have an influence on the film quality at larger film thicknesses, are sensitively dependent on the substrate temperature. At a film thickness of 200 nm the increase of the substrate temperature up to 225°C leads to smooth, completely coalesced epitaxial C60-thin films characterized by a roughness smaller than 1.5 nm, a mosaic spread Δω of 0.1° and an azimuthal alignment ΔΦ of 0.45°.

A Structural Study of SrBi2Ta2O9 - Bi3TiNbO9 Ferroelectric Thin Films

1999 ◽  
Vol 596 ◽  
Author(s):  
E. Ching-Prado ◽  
W. Pérez ◽  
P. S. Dobalt ◽  
R. S. Katiyart ◽  
S. Tirumala ◽  
...  
Keyword(s):  
Thin Films ◽  
Remanent Polarization ◽  
Electrical Characterization ◽  
X Ray Diffraction ◽  
Electrical Measurements ◽  
Solution Deposition ◽  
Force Microscopy ◽  
Si Substrates ◽  
Atomic Force ◽  
Metal Organic

AbstractThin films of ferroelectric (SrBi2Ta2O9)x(Bi3TiNbO9)1-x layered structure (for x = 0.0, 0.2, … 1.0) were prepared by a metal organic solution deposition method on Pt/TiO2/SiO2/Si substrates. Raman spectroscopy, X-ray diffraction, atomic force microscopy (AFM), and electrical characterization techniques were utilized to study the inclusion of SrBi2Ta2O9 (SBT) in the Bi3TiNbO9 (BTN) system. The Raman spectra show frequency shifts and broadening of modes as x increases from 0.0 to 0.4, which are related to the nature of Sr and Bi in the A-sites, and Ta, Ti, and Nb in the B-sites. Smooth surfaces without any cracks or defects were evidenced in each of these films by AFM. These images also indicate that the grain size in the films increases with increasing SBT content in the BTN compound. Electrical measurements show that the remanent polarization (Pr) and the coercive field (Ec) values in the x=0.0 film (2 μC/cm2 and 30 kV/cm, respectively) increase to 12.5 μC/cm2 and 125 kV/cm for x=0.6. A decrease in these parameters was found for higher compositions.

Effect of Ti Sputtering Current on Structure of TiCrN Thin Films Prepared by Reactive DC Magnetron Co-Sputtering

2016 ◽  
Vol 675-676 ◽  
pp. 181-184 ◽  
Author(s):  
Nirun Witit-Anun ◽  
Amphol Teekhaboot
Keyword(s):  
Thin Films ◽  
Crystal Size ◽  
X Ray Diffraction ◽  
X Ray ◽  
Force Microscopy ◽  
Lattice Constants ◽  
Atomic Force ◽  
Glancing Angle ◽  
Deposited Films ◽  
Section Analysis

Titanium chromium nitride (TiCrN) thin films were deposited by reactive DC magnetron co-sputtering. The effect of Ti sputtering current (ITi) on the structure of the TiCrN thin films were investigated. The crystal structure, microstructure, thickness, roughness and elemental composition were characterized by glancing angle X-ray diffraction (GAXRD), field emission scanning electron microscopy (FE-SEM), atomic force microscopy (AFM) and energy dispersive X-ray spectroscopy (EDS) technique, respectively. The results showed that, all the as-deposited films were formed as a (Ti,Cr)N solid solution. The as-deposited films exhibited a nanostructure with a crystallite size of less than 40 nm. The crystal size decreased from 39.9 nm to 33.5 nm, while the lattice constants increased from 4.139 Å to 4.162 Å, with increasing of the Ti sputtering current. The film thickness and roughness were found to increase from 397 nm to 615 nm and 3.7 nm to 6.3 nm, respectively, with increasing of the Ti sputtering current. The composition of the as-deposited films varied with the Ti sputtering current. Cross section analysis by FE-SEM showed compact columnar and dense morphology as a result of increasing the Ti sputtering current.

Synthesis and Characterization of Semiconductor Composites Gas Sensors Based on ZnO Doped TiO2 Thin Films by Laser-Induced Plasma

2021 ◽  
Vol 900 ◽  
pp. 112-120
Author(s):  
Souad G. Khalil ◽  
Mahdi M. Mutter
Keyword(s):  
Thin Films ◽  
Gas Sensing ◽  
Operating Temperature ◽  
Electrical Characterization ◽  
X Ray Diffraction ◽  
Type Conductivity ◽  
Force Microscopy ◽  
Atomic Force ◽  
P Type

This work presents the development of n-type (TiO2) and p-type (ZnO) gas-sensitive materials from ZnO doped TiO2 thin films prepared by pulsed laser deposition technique (PLD) on a glass substrate as a gas sensor of CO2 gas. TiO2 gas-sensing layers have been deposited over a range of ZnO content (0, 20, and 40) wt %. The obtained thin films analysis by atomic force microscopy (AFM), and X-ray diffraction (XRD). Electrical characterization shows that TiO2:ZnO thin films were p-type conductivity and ZnO added was unable to change the composition to the n-type conductivity. There are notable gas-sensing response differences between n-type and p-type ZnO doped TiO2 thin film. The responses toward all tested oxidizing gases tend to increase with operating temperature for the n-type TiO2 films. Besides, the p-type ZnO doping results in a significant response improvement toward tested oxidizing gases such as CO2 gas at the low operating temperature of 60 °C.

A low-temperature and low-cost method to produce high-quality epitaxial anatase TiO2 thin films

2005 ◽  
Vol 20 (2) ◽  
pp. 292-294 ◽  
Author(s):  
Zhaoming Zhang
Keyword(s):  
Thin Films ◽  
Low Cost ◽  
X Ray Diffraction ◽  
Tio2 Thin Films ◽  
Epitaxial Relationship ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Average Size ◽  
Lattice Matched

Epitaxial anatase TiO2 thin films were successfully grown on lattice-matched SrTiO3 (001) substrates by a novel hydrothermal method at very low temperatures (120–200 °C). This method is extremely simple and inexpensive in that the SrTiO3 substrate itself provides the source material for the TiO2 film. X-ray diffraction confirmed the high crystallinity and phase purity of the anatase films. The epitaxial relationship between the film and the substrate was determined as (001)[100]anatase // (001)[100]SrTiO3. Atomic force microscopy revealed the average size of the anatase crystallites as approximately 50 to 200 nm.

Nanocrystalline Solutions as Precursors to The Spray Deposition of Cdte Thin Films

1995 ◽  
Vol 382 ◽  
Author(s):  
Martin Pehnt ◽  
Douglas L. Schulz ◽  
Calvin J. Curtis ◽  
Helio R. Moutinho ◽  
Amy Swartzlander ◽  
...  
Keyword(s):  
Thin Films ◽  
Atomic Force Microscopy ◽  
Grain Size ◽  
X Ray Diffraction ◽  
X Ray ◽  
Force Microscopy ◽  
Cdte Nanoparticles ◽  
Atomic Force ◽  
Vis Spectroscopy ◽  
Cdte Thin Films

ABSTRACTIn this article we report the first nanoparticle-derived route to smooth, dense, phase-pure CdTe thin films. Capped CdTe nanoparticles were prepared by injection of a mixture of Cd(CH3)2, (n-C8H17)3 PTe and (n-C8H17)3P into (n-C8H17)3PO at elevated temperatures. The resultant nanoparticles 32-45 Å in diameter were characterized by x-ray diffraction, UV-Vis spectroscopy, transmission electron microscopy, thermogravimetric analysis and energy dispersive x-ray spectroscopy. CdTe thin film deposition was accomplished by dissolving CdTe nanoparticles in butanol and then spraying the solution onto SnO2-coated glass substrates at variable susceptor temperatures. Smooth and dense CdTe thin films were obtained using growth temperatures approximately 200 °C less than conventional spray pyrolysis approaches. CdTe films were characterized by x-ray diffraction, UV-Vis spectroscopy, atomic force microscopy, and Auger electron spectroscopy. An increase in crystallinity and average grain size as determined by x-ray diffraction was noted as growth temperature was increased from 240 to 300 °C. This temperature dependence of film grain size was further confirmed by atomic force microscopy with no remnant nanocrystalline morphological features detected. UV-Vis characterization of the CdTe thin films revealed a gradual decrease of the band gap (i.e., elimination of nanocrystalline CdTe phase) as the growth temperature was increased with bulk CdTe optical properties observed for films grown at 300 °C.

Studies of Nanomechanical Properties of Pulsed Laser Deposited NbN films on Si Using Nanoindentation

2012 ◽  
Vol 1424 ◽  
Author(s):  
M. A. Mamun ◽  
A. H. Farha ◽  
Y. Ufuktepe ◽  
H. E. Elsayed-Ali ◽  
A. A. Elmustafa
Keyword(s):  
Thin Films ◽  
Pulsed Laser ◽  
Niobium Nitride ◽  
X Ray Diffraction ◽  
Si Substrate ◽  
Force Microscopy ◽  
Atomic Force ◽  
Wide Range ◽  
Pile Up ◽  
Average Modulus

ABSTRACTNanomechanical and structural properties of pulsed laser deposited niobium nitride thin films were investigated using X-ray diffraction, atomic force microscopy, and nanoindentation. NbN film reveals cubic δ-NbN structure with the corresponding diffraction peaks from the (111), (200), and (220) planes. The NbN thin films depict highly granular structure, with a wide range of grain sizes that range from 15-40 nm with an average surface roughness of 6 nm. The average modulus of the film is 420±60 GPa, whereas for the substrate the average modulus is 180 GPa, which is considered higher than the average modulus for Si reported in the literature due to pile-up. The hardness of the film increases from an average of 12 GPa for deep indents (Si substrate) measured using XP CSM and load control (LC) modes to an average of 25 GPa measured using the DCM II head in CSM and LC modules. The average hardness of the Si substrate is 12 GPa.

DIRECT GROWTH OF EPITAXIAL La0.67Ca0.33MnO3 - δ THIN FILMS

2002 ◽  
Vol 09 (05n06) ◽  
pp. 1611-1615 ◽  
Author(s):  
G. CAMPILLO ◽  
L. F. CASTRO ◽  
P. VIVAS ◽  
E. BACA ◽  
P. PRIETO ◽  
...  
Keyword(s):  
Thin Films ◽  
Substrate Surface ◽  
Electrical Characterization ◽  
Annealing Treatment ◽  
Pure Oxygen ◽  
X Ray Diffraction ◽  
Atomic Force ◽  
Transmission Electron ◽  
Afm Analysis ◽  
Direct Growth

La 0.67 Ca 0.33 MnO 3 - δ thin films were deposited using a high-pressure dc-sputtering process. Pure oxygen at a pressure of 3.8 mbar was used as sputtering gas. The films were grown on (001) LaAlO 3 and (001) SrTiO 3 substrates at heater temperature of 850° without any annealing treatment. The formation of highly a-axis-oriented films with sharp interface with substrate surface is demonstrated by X-ray diffraction, transmission electron microscope (TEM), and atomic force microscope (AFM) analysis. Electrical characterization revealed a metal–insulator transition at T MI = 276 K, and magnetic characterization showed good magnetic properties with a PM–FM transition at TC ≈ 262 K.

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