Delafossite-CuAlO2 Thin Films Prepared by Thermal Annealing

2011 ◽  
Vol 13 ◽  
pp. 81-86 ◽  
Author(s):  
Hong Ying Chen ◽  
Ming Wei Tsai

Transparent conducting oxides (TCOs) are well known and have been widely used for a long time in optoelectronics industries. The most popular TCOs have n-type characteristics. However p-type material is not well established and examined. The delafossite-CuAlO2 is one of the p-type TCOs. In this paper, amorphous Cu-Al-O films were deposited onto (100) p-type silicon substrate by magnetron sputtering. After that, the films were annealed at 800°C for 2 h in different partial oxygen levels ranging from 5*10-5 to 1 atm with N2, air, and O2. X-ray diffraction patterns showed that as-deposited films were amorphous. In addition, delafossite-CuAlO2 (R m and P63/mmc phase) appeared at 800°C in N2, but monoclinic-CuO and spinel-CuAl2O4 phases existed in air and O2. The formation of delafossite-CuAlO2 phase can be explained with thermodynamics. The optoelectronic properties of delafossite-CuAlO2 films were also measured. The direct optical bandgap was around at 3.3 eV, which is comparable with literature data. The electrical conductivity was obtained to be 6.8*10-3 S/cm. The hot-probe method employed to measure the electrical property of the films, which indicates that delafossite-CuAlO2 films have p-type characteristics.

2005 ◽  
Vol 905 ◽  
Author(s):  
Cleva Ow-Yang ◽  
Hyo-Yong Yeom ◽  
Burag Yaglioglu ◽  
David C. Paine

AbstractAmorphous ZITO films were deposited by dc magnetron sputtering onto glass substrates from ceramic oxide targets containing Zn:In:Sn cation ratios of 1:2:1 and 1:2:1.5. The microstructure, carrier density, mobility, and resistivity of as-deposited and annealed samples were evaluated using x-ray diffraction and Hall effect measurements. The as-deposited films were amorphous and remained so after annealing at 200°C in air for up to five hours. Transmissivity of the films exceeded 80% in the visible spectral region. The minimum resistivity value (7.6×10−4 Ω-cm) was obtained from thin films deposited using the 1:2:1 composition target and a substrate temperature of 300°C.


2009 ◽  
Vol 68 ◽  
pp. 69-76 ◽  
Author(s):  
S. Thanikaikarasan ◽  
T. Mahalingam ◽  
K. Sundaram ◽  
Tae Kyu Kim ◽  
Yong Deak Kim ◽  
...  

Cadmium iron selenide (Cd-Fe-Se) thin films were deposited onto tin oxide (SnO2) coated conducting glass substrates from an aqueous electrolytic bath containing CdSO4, FeSO4 and SeO2 by potentiostatic electrodeposition. The deposition potentials of Cadmium (Cd), Iron (Fe), Selenium (Se) and Cadmium-Iron-Selenide (Cd-Fe-Se) were determined from linear cathodic polarization curves. The deposited films were characterized by x-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive analysis by x-rays (EDX) and optical absorption techniques, respectively. X-ray diffraction patterns shows that the deposited films are found to be hexagonal structure with preferential orientation along (100) plane. The effect of FeSO4 concentration on structural, morphological, compositional and optical properties of the films are studied and discussed in detail.


2021 ◽  
Vol 24 (2) ◽  
pp. 27-32
Author(s):  
Suroor H. Taha ◽  
◽  
Thamir A. Jumah ◽  

Zirconium dioxide was prepared as a thin film by using pulse laser deposition (PLD).Subsequently, the films had been thermally treated by annealing process at temperature 450 oC. The structural and electrical parameters of thin films were investigated. As-deposited films were amorphous and had a large surface density of ablated particles. The Annealing process resulted change the phase from amorphous to polycrystalline. The X-ray diffraction of all these films has a polycrystalline structure with two different phases named tetragonal and monoclinic. Hall measurements indicate that the charge carriers of all these films were p-type. In addition, the Hall coefficient suffers some change with thin film thickness. The AC results measured showed the films have resistance and capacitance properties. The AC conduction is dominated by hole cattier.


1998 ◽  
Vol 545 ◽  
Author(s):  
Yunki Kim ◽  
Sunglae Cho ◽  
Antonio DiVenere ◽  
George K. Wong ◽  
Jerry R. Meyer ◽  
...  

AbstractThin films of the hexagonal phase of Bi1-xTe1+x have been grown on CdTe(111) substrates using molecular beam epitaxy (MBE). Analysis of X-ray diffraction patterns (θ-2θ scans and rocking curves) of the films shows that their crystallinity depends upon the compositional deviation from stoichiometric BiTe. Measurements of the temperature-dependent thermoelectric power (TEP) of the films reveals that compositional changes cause the TEP to vary from electron dominant (n-type) to hole dominant (p-type), implying their possible application as a thermoelectric cooler or power generator. Measurements of the temperature-dependent resistivity of the films were conducted, and the analysis shows semimetallic behavior. These results demonstrate that Bi1-xTe1+xis an appropriate model system to study the dependencies of thermoelectric and structural properties on binary composition.


2013 ◽  
Vol 341-342 ◽  
pp. 129-133
Author(s):  
Juan Qin ◽  
Niu Yi Sun ◽  
Guo Hua Wang ◽  
Min Zhang ◽  
Wei Min Shi ◽  
...  

TiCoSb-based half-Heusler compounds, which are narrow band gap semiconductors with a high Seebeck coefficient, have been intensively studied in bulk form but rarely in thin films. In this article TiFexCo1-xSb (x=0, 0.17) thin films were synthesized on n-type single crystal Si (100) and MgO (100) substrates by DC magnetron sputtering followed by rapid thermal annealing. The X-ray diffraction patterns show that Fe doping does not affect the crystallization temperature of TiCoSb phase, but seem to induce the formation of binary phases like TiSb. Hall measurements reveal that the undoped TiCoSb thin films are n-type semiconducting, while TiFe0.2Co0.8Sb turns to p-type with half-order higher carrier concentration of 1.5×1021cm-3. The vibrating sample magnetometer spectrum indicate that the TiCoSb thin film is non-magnetic and TiFexCo1-xSb (x=0.17) is weak magnetic.


2021 ◽  
Vol 323 ◽  
pp. 152-158
Author(s):  
Shou Yuan Xing ◽  
Song Lin ◽  
Zhi Qiang Song ◽  
Zhi Qiang Ou

We reported the structural, magnetic and magenetocaloric properties of Mn1.25Fe0.75P0. 50Si0.50Bx(x = 0.01, 0.02 and 0.04) X-ray diffraction patterns show that all compounds crystallize in the hexagonal Fe2P-type crystal structure. Lattice parameter a increases while c decreases with increasing B contents. The Curie temperature of the compounds have been determined, the values are 219, 268 and 323.2 K for x = 0.01, 0.02, 0.04, respectively. The maximum magnetic entropy changes in a field change of 0~1.5 T are 6.1, 5.3 and 3.5J/kg·K for x = 0.01, 0.02 and 0.04, respectively.


2005 ◽  
Vol 04 (04) ◽  
pp. 725-729 ◽  
Author(s):  
RANGARAO ARNEPALLI ◽  
VIRESH DUTTA

Cadmium Telluride: Iodine nanoparticle thin films were prepared by spraying iodine doped CdTe nanoparticles dispersed in 1-Butanol, on the glass substrates kept at 200°C for 20 min. Iodine doped CdTe nanoparticles had been prepared by adding trace amounts of Iodine powder in addition to stoichiometric ratios of Cd and Te in the Solvothermal synthesis. The films were prepared by applying without a voltage and with a voltage of 700 V to the nozzle during the deposition. The presence of iodine in the films was confirmed by the sign of voltage generated (positive relative to the cold end) in the hot probe method and also from the elemental analysis using X-ray Photoelectron Spectroscopy. X-ray diffraction patterns of the films showed predominantly Hexagonal CdTe peaks in both the cases. From the transmission spectra of the films the bandgap was found to be 1.77 eV against the bulk CdTe bandgap of 1.5 eV. The band edge was not as sharp as compared to that in case of the undoped films. SEM and TEM micrographs of both the films revealed the formation of Nanofibers.


Materials ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 267 ◽  
Author(s):  
David Caffrey ◽  
Ainur Zhussupbekova ◽  
Rajani K. Vijayaraghavan ◽  
Ardak Ainabayev ◽  
Aitkazy Kaisha ◽  
...  

The electronic and optical properties of transparent conducting oxides (TCOs) are closely linked to their crystallographic structure on a macroscopic (grain sizes) and microscopic (bond structure) level. With the increasing drive towards using reduced film thicknesses in devices and growing interest in amorphous TCOs such as n-type InGaZnO 4 (IGZO), ZnSnO 3 (ZTO), p-type Cu x CrO 2 , or ZnRh 2 O 4 , the task of gaining in-depth knowledge on their crystal structure by conventional X-ray diffraction-based measurements are becoming increasingly difficult. We demonstrate the use of a focal shift based background subtraction technique for Raman spectroscopy specifically developed for the case of transparent thin films on amorphous substrates. Using this technique we demonstrate, for a variety of TCOs CuO, a-ZTO, ZnO:Al), how changes in local vibrational modes reflect changes in the composition of the TCO and consequently their electronic properties.


2008 ◽  
Vol 15 (03) ◽  
pp. 301-306
Author(s):  
B. NATARAJAN ◽  
N. JEYAKUMARAN ◽  
S. RAMAMURTHY ◽  
V. VASU

Transparent conducting indium tin oxide (ITO) films are deposited on Porous Silicon (PS) substrates by spray pyrolysis technique. In this process, the films are formed over the surface and also incorporated into the pores of PS and thereby making a protecting layer as well as a contacting terminal. Thus, the ITO/PS/ Si heterojunction light-emitting devices are fabricated. The growth of ITO on PS is thoroughly investigated by SEM and X-ray diffraction techniques. The features of growth on other substrates like single-crystal p-type (100) silicon and glass are also taken into consideration. The influence on the PS interface is correlated with the electrical and luminescent behavior of the resulting heterojunction diode structure.


2014 ◽  
Vol 17 (3) ◽  
pp. 173-177
Author(s):  
B. Bharathi ◽  
S. Thanikaikarasan ◽  
Pratap Kollu ◽  
P. V. Chandrasekar ◽  
T. Mahalingam ◽  
...  

Thin films of NiO have been prepared using potentiostatic electrodeposition technique from an aqueous electrolytic bath containing NiSO4. Deposited films have been characterized using x-ray diffraction, scanning electron microscopy and energy dispersive analysis by x-rays. X-ray diffraction patterns showed that the prepared films possess polycrystalline nature with face centered cubic structure. Surface morphology and film composition showed that films with better stoichiometry and smooth surface are obtained at optimized growth condition. Optical absorption analysis showed that the prepared films possess direct band gap value around 3.46 eV.


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