Formation of high temperature phase in flash-evaporated SnSe films

1990 ◽  
Vol 48 (4) ◽  
pp. 698-699
Author(s):  
J.P.S. Hanjra
Keyword(s):  
Thin Films ◽  
Electrical Properties ◽  
Energy Gap ◽  
Dominant Role ◽  
Fine Powder ◽  
High Temperature Phase ◽  
Temperature Phase ◽  
Water Mixture ◽  
Flash Evaporation ◽  
Photovoltaic Applications

Tin mono selenide (SnSe) with an energy gap of about 1 eV is a potential material for photovoltaic applications. Various authors have studied the structure, electronic and photoelectronic properties of thin films of SnSe grown by various deposition techniques. However, for practical photovoltaic junctions the electrical properties of SnSe films need improvement. We have carried out investigations into the properties of flash evaporated SnSe films. In this paper we report our results on the structure, which plays a dominant role on the electrical properties of thin films by TEM, SEM, and electron diffraction (ED).Thin films of SnSe were deposited by flash evaporation of SnSe fine powder prepared from high purity Sn and Se, onto glass, mica and KCl substrates in a vacuum of 2Ø micro Torr. A 15% HF + 2Ø% HNO3 solution was used to detach SnSe film from the glass and mica substrates whereas the film deposited on KCl substrate was floated over an ethanol water mixture by dissolution of KCl. The floating films were picked up on the grids for their EM analysis.

Temperature/Doping-Dependency of the Electrical Properties of the Nickel Doped Copper Oxide Thin Films

2021 ◽  
Vol 16 (2) ◽  
pp. 163-169
Author(s):  
Alaa Y. Mahmoud ◽  
Wafa A. Alghameeti ◽  
Fatmah S. Bahabri
Keyword(s):  
Thin Films ◽  
Activation Energy ◽  
Electrical Properties ◽  
Thermal Activation ◽  
Doping Concentration ◽  
Energy Gap ◽  
Cupric Oxide ◽  
Electrical Energy ◽  
Thermal Activation Energy ◽  
Ni Doping

The electrical properties of the Nickel doped cupric oxide Ni-CuO thin films with various doping concentrations of Ni (0, 20, 30, 70, and 80%) are investigated at two different annealing temperatures; 200 and 400 °C. The electrical properties of the films; namely thermal activation energy and electrical energy gap are calculated and compared. We find that for the non-annealed Ni-CuO films, both thermal activation energy and electrical energy gap are decreased by increasing the doping concentration, while for the annealed films, the increase in the Ni doping results in the increase in thermal activation energy and electrical energy gap for most of the Ni-CuO films. We also observe that for a particular concentration, the annealing at 200 °C produces lower thermal activation energy and electrical energy gap than the annealing at 400 °C. We obtained two values of the activation energy varying from -5.52 to -0.51 eV and from 0.49 to 3.36 eV, respectively, for the annealing at 200 and 400 °C. We also obtained two values of the electrical bandgap varying from -11.05 to -1.03 eV and from 0.97 to 6.71 eV, respectively, for the annealing at 200 and 400 °C. It is also noticeable that the increase in the doping concentration reduces the activation energy, and hence the electrical bandgap energies.

Structural behavior of zirconia thin films with different level of yttrium content

2002 ◽  
Vol 756 ◽  
Author(s):  
V. Petrovsky ◽  
H. U. Anderson ◽  
T. Petrovsky ◽  
E. Bohannan
Keyword(s):  
Thin Films ◽  
Grain Size ◽  
Solid Oxide Fuel Cells ◽  
Annealing Temperature ◽  
Sintered Material ◽  
High Temperature Phase ◽  
Temperature Phase ◽  
X Ray Diffraction ◽  
Oxygen Ion ◽  
Cubic Structure

ABSTRACTThe preparation of dense, high conductive electrolyte layers is important for the development of intermediate temperature solid oxide fuel cells and other devices based on oxygen-ion conductivity. Thus a number of techniques have been used to produce these structures. This study makes use of one of these methods to produce dense nanocrystalline 0.1 to 1 micron layers of zirconia.Polymeric precursors were used to prepare zirconia films with different level of yttrium substitution. The films were annealed at a series of temperatures in the range of 400 to 1000°C and were characterized via scanning electron microscopy (SEM) and X-ray diffraction (XRD). It was found that initially (after 400°C annealing) the films had cubic structure and grain size of ∼5 nm regardless of Y content. The situation changed when the annealing temperature was increased. Y (16mol %) stabilized zirconia (YSZ) did remain cubic over the entire temperature region investigated (up to 1000°C), but for compositions with lower Y content changes in crystal structure occurred. The samples with 4 and 8mol% Y transformed to the tetragonal phase at about 700°C, and undoped zirconia became monoclinic at the same temperature.The results were compared with sintered zirconia and it was shown that the behavior of thin films is quite similar to that of the sintered material, if the annealing temperature was high enough (>700°C). The main differences between polymeric prepared films and sintered material are the existence of the cubic structure at low temperatures (< 600°C) and lower transition temperatures to the high temperature phase, which can be explained by small initial grain size in polymer-derived zirconia.

Influence of Annealing Temperature on Structural, Morphological, Optical and Electrical Properties of Sol-Gel SnO2 Thin Films

2018 ◽  
Vol 52 ◽  
pp. 15-20 ◽  
Author(s):  
Ji Tao Li ◽  
Ding Yu Yang ◽  
Xing Hua Zhu ◽  
Xu Li ◽  
Shu Qi Chen ◽  
...  
Keyword(s):  
Thin Films ◽  
Electrical Properties ◽  
Annealing Temperature ◽  
Energy Gap ◽  
Raw Materials ◽  
Sol Gel ◽  
Optical Energy Gap ◽  
Sem Images ◽  
Rutile Structure ◽  
Chloride Dihydrate

SnO2 thin films were prepared on glass substrates by sol-gel spin coating method using stannous chloride dihydrate and ethyl alcohol absolute as raw materials at annealing temperature 450-550 °C. The crystal phase was measured by X-ray diffraction (XRD) and showed tetragonal rutile structure with a preferential orientation of (110). Atomic force microscope (AFM) and Scanning Electron Microscope (SEM) images revealed the homogeneous grains distribution, and SEM images showed the obvious rectangular objects corresponding to tetragonal structure. Optical properties were observed by the transmittance in ultraviolet-visible (UV-Vis) region and optical energy gap, which revealed the transmittance over 75% and energy gap between 3.84 eV and 3.89 eV. Finally, I-V characteristics were tested to research electrical properties, and found the gradual non-linear property and the increase of resistance.

Bandgap engineered high mobility indium oxide thin films for photovoltaic applications

2011 ◽  
Vol 1315 ◽  
Author(s):  
R.K. Gupta ◽  
K. Ghosh ◽  
P.K. Kahol
Keyword(s):  
Thin Films ◽  
Electrical Resistivity ◽  
Electrical Properties ◽  
Carrier Concentration ◽  
Indium Oxide ◽  
Growth Temperature ◽  
High Mobility ◽  
Optical Transparency ◽  
Metallic Behavior ◽  
Photovoltaic Applications

ABSTRACTMagnesium and titanium doped indium oxide (IMTO) thin films were grown using pulsed laser deposition technique. Magnesium was added to enhance the bandgap, whereas titanium was added to improve carrier concentrations and mobility of indium oxide films. The effect of growth temperature on structural, optical, and electrical properties were studied. It was observed that the optical transparency of the films strongly depends on growth temperature and increases with increase in growth temperature. The films grown at 600 °C showed optical transparency > 85%. We observed widening in bandgap of indium oxide by doping with magnesium and titanium. The bandgap of IMTO films increases with increase in growth temperature. The maximum bandgap of 3.9 eV was observed for film grown at 600 °C. It was observed that growth temperature strongly affects the electrical properties such as resistivity, carrier concentration, and mobility. The electrical resistivity and mobility of the films increases with increase in growth temperature. On the other hand, carrier concentration decreases with increase in growth temperature. Temperature dependence electrical resistivity measurements showed that films grown at low temperatures are semiconducting in nature, while films grown at high temperature showed transition from semiconducting to metallic behavior. These wide bandgap, highly transparent, and high mobility films could be used for photovoltaic applications.

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