Influence of post-deposition annealing on structural, optical and electrical characteristics of NiO/ZnO thin film hetero-junction

2012 ◽  
Vol 1394 ◽  
Author(s):  
Manisha Tyagi ◽  
Monika Tomar ◽  
Vinay Gupta
Keyword(s):  
Electronic Device ◽  
Forward Bias ◽  
Visible Region ◽  
Rf Sputtering ◽  
Reverse Current ◽  
Annealing Treatment ◽  
Xrd Analysis ◽  
Device Fabrication ◽  
Post Deposition Annealing ◽  
Post Deposition

ABSTRACTTransparent p-n hetero-junction diodes are fabricated using, p-type NiO and n-type ZnO thin films deposited onto a Pt/Ti/glass substrate utilizing RF sputtering technique. The prepared hetero-junctions are studied for the structural, electrical and optical properties and the effect of post-deposition annealing is investigated through I-V measurements and XRD analysis. The as deposited hetero-junction is found to be giving ohmic behaviour while with post-annealing treatment it result in rectification with a ratio of forward-to-reverse current as high as 15 in the range -1.0 to 1.0 V. Forward threshold and the reverse breakdown voltages are found to be about 0.5 and -2.7 V, respectively. The forward-bias I-V characteristics are dominated by the flow of space-charge-limited current with an optical transmission of above 50 % in the visible region important for the transparent electronic device fabrication.

scholarly journals Large-area, continuous and high electrical performances of bilayer to few layers MoS2 fabricated by RF sputtering via post-deposition annealing method

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Sajjad Hussain ◽  
Jai Singh ◽  
Dhanasekaran Vikraman ◽  
Arun Kumar Singh ◽  
Muhammad Zahir Iqbal ◽  
...  
Keyword(s):  
Rf Sputtering ◽  
Large Area ◽  
Post Deposition Annealing ◽  
Post Deposition ◽  
Annealing Method

Layer-modulated, wafer scale and continuous ultra-thin WS2 films grown by RF sputtering via post-deposition annealing

2016 ◽  
Vol 4 (33) ◽  
pp. 7846-7852 ◽  
Author(s):  
Sajjad Hussain ◽  
Muhammad Farooq Khan ◽  
Muhammad Arslan Shehzad ◽  
Dhanasekaran Vikraman ◽  
Muhammad Zahir Iqbal ◽  
...  
Keyword(s):  
Thin Films ◽  
Rf Sputtering ◽  
Large Area ◽  
Post Deposition Annealing ◽  
Wafer Scale ◽  
Post Deposition ◽  
Insulating Substrates

Synthesis of large-area WS2 films by direct sulfurization of RF-sputtered WO3 thin films on insulating substrates.

scholarly journals Effects of Temperature on the Structural and Optical Preperties of AgGaSe2 Thin Films

1970 ◽  
Vol 33 (2) ◽  
pp. 179-188
Author(s):  
MRA Bhuiyan ◽  
DK Saha ◽  
SM Firoz Hasan
Keyword(s):  
Thin Films ◽  
Annealing Temperature ◽  
Visible Region ◽  
Wavelength Region ◽  
Band Gap Energy ◽  
Post Deposition Annealing ◽  
X Ray ◽  
Glass Substrates ◽  
Academy Of Sciences ◽  
Post Deposition

In this study, AgGaSe2 (AGS) thin films were formed onto cleaned glass substrates by using the stacked elemental layer (SEL) deposition technique in vacuum. The films were prepared at the post-deposition annealing temperature from 100 to 350°C for 15 min duration. The atomic composition of the films was measured by energy dispersive analysis of X-ray (EDAX) method. The films ascertain the compositional uniformity. The X-ray diffraction (XRD) has been employed to study the structure of the films. The structures of the films are found to be polycrystalline in nature. The lattice parameters, grain size, strain and dislocation densities of the films were calculated. Optical characteristics of the films were ascertained by spectrophotometer in the photon wavelength ranging between 300 and 2500 nm. The transmittance was found to increase with the increase of annealing temperature. The transmittance falls steeply with decreasing wavelength. It revealed that AGS films have considerable absorption throughout the wavelength region from 400 to 800 nm. The optical band gap energy has been evaluated. Two possible direct allowed and direct forbidden transitions have been observed for all the AGS films in visible region. The former varied from 1.67 to 1.75 eV and the later from 2.05 to 2.08 eV, depending on the post-deposition annealing temperature of the films. DOI: 10.3329/jbas.v33i2.4101 Journal of Bangladesh Academy of Sciences, Vol. 33, No. 2, 179-188, 2009

scholarly journals Studies on the Electrical and Optical Properties of Magnesium Phthalocyanine Thin Films

2004 ◽  
Vol 1 (5) ◽  
pp. 231-236
Author(s):  
T. G. Gopinathan ◽  
C. S. Menon
Keyword(s):  
Thin Films ◽  
Electrical Conductivity ◽  
Visible Region ◽  
Absolute Temperature ◽  
Post Deposition Annealing ◽  
Glass Substrates ◽  
Absorption Studies ◽  
Evaporation Technique ◽  
Uv Visible ◽  
Post Deposition

Thin films of Magnesium Phthalocyanine (MgPc) are prepared by thermal evaporation technique at a base pressure of 10-5m.bar on thoroughly cleaned glass substrates kept at different constant temperatures. Films of thickness 2400 A.U. coated at room temperature are subjected to post deposition annealing in air by keeping them in a furnace at different constant temperatures, for one hour. The electrical conductivity studies are conducted in the temperature range 300 K to 525 K. The electrical conductivity is plotted as a function of absolute temperature. The conduction mechanism is observed to be hopping. The thermal activation energy is calculated in different cases and is observed to vary with substrate temperature and annealing temperature. A phase change is observed due to post-deposition annealing at around 523 K. The optical absorption studies are done in the UV-Visible region. The optical band gap energies of the samples are calculated.

Effects of Post-Deposition Processing on the Ultimate Grain Size in Metastable Semiconductor Thin Films to be Used in IR Detectors

1994 ◽  
Vol 343 ◽  
Author(s):  
Susanne M Lee
Keyword(s):  
Thin Films ◽  
Thick Films ◽  
Rf Sputtering ◽  
Solubility Limit ◽  
Nucleation And Growth ◽  
Separation Mechanism ◽  
Post Deposition Annealing ◽  
Ir Detectors ◽  
Solid Solubility Limit ◽  
Post Deposition

ABSTRACTThrough post-deposition annealing in a differential scanning calorimeter (DSC), we have manufactured both thin (200 nm) and bulk (8000 nm) single phase films of crystalline Ge1–xSnx, using rf sputtering. The Sn concentrations produced ranged up to 31 at.%, well beyond the solid solubility limit of this system. There was a marked difference, in the asdeposited structure, between thick and thin films produced under the same deposition conditions. Quantitative models for both systems are given in this paper and were deduced frorn DSC measurements in conjunction with electron microscopy. The metastable crystalline state in the thin films formed by nucleation and growth from an amorphous phase; whereas in the thick films, the desired phase was already present in the as-deposited films and only growth of preexisting grains was observed upon post-deposition annealing. When annealed to high temperature, the Sn phase separates from the alloys and we postulate here that it does so by nucleation and growth of β-Sn. With this hypothesis, the Sn separation in the 8000 nm thick films was accurately modeled by a two-mechanism process, however, in the 200 nm thick films, only one phase separation mechanism was necessary to accurately fit the data. Both models were corroborated by the subsequent melting behavior of the phase separated Sn which, though it varied depending on the sample being measured, always exhibited a melting endotherm starting 25–35°C lower than the bulk melting temperature of Sn. Speculation on the reasons for this are presented.

NOISE CHARACTERISTICS AND RELIABILITY OF LIGHT EMITTING DIODES BASED ON NITRIDES

2007 ◽  
Vol 07 (03) ◽  
pp. L367-L378 ◽  
Author(s):  
SANDRA PRALGAUSKAITĖ ◽  
VILIUS PALENSKIS ◽  
JONAS MATUKAS ◽  
JUOZAS PETRULIS ◽  
GENADIJUS KURILČIK
Keyword(s):  
Light Emitting Diodes ◽  
Forward Bias ◽  
Reverse Current ◽  
Correlation Factor ◽  
Device Fabrication ◽  
Electrical Noise ◽  
Device Structure ◽  
Light Emitting ◽  
Noise Characteristics ◽  
Terminal Voltage

Optical and electrical noises and correlation factor between optical and electrical fluctuations of nitride-based light emitting diodes (LEDs) have been investigated under forward bias. Their electrical, optical and noise characteristics were compared with ones of LEDs of other materials. LED noise characteristic changes during aging have been measured, too. It is found that optical and electrical noise spectra under forward bias for more reliable LEDs distinguish by lower l/f type fluctuations and Lorentzian type noise at higher frequencies. LEDs with intensive 1/f noise demonstrate shorter lifetime. It is shown that reason of LED degradation is related with defects presence in device structure. These defects can be formed during device fabrication or appear during operation. An analysis of LED current-voltage and electrical noise characteristics under forward and reverse bias has shown that LEDs with intensive 1/f electrical noise, large reverse current (low reverse breakdown voltage) and larger terminal voltage under forward bias distinguish by short lifetime.

The Effect on Physical, Electrical and Structural Parameters of RF Sputtered Molybdenum Thin Film

2011 ◽  
Vol 403-408 ◽  
pp. 5092-5096 ◽  
Author(s):  
Mukter Zaman ◽  
Gunawan Witjaksono ◽  
Teh Aun Shih ◽  
Shabiul Islam ◽  
Masuri Othman ◽  
...  
Keyword(s):  
Thin Film ◽  
Deposition Rate ◽  
Rate Increase ◽  
Structural Parameters ◽  
Rf Sputtering ◽  
Xrd Analysis ◽  
Device Fabrication ◽  
Structural Parameter ◽  
Rf Power ◽  
Deposition Parameters

In this study, the physical, electrical, and structural parameter on radio frequency (RF) sputtered molybdenum thin film is investigated as a function of two deposition parameters: rf power, and argon (Ar) pressure. Films are sputtered onto the substrates nominally held in room temperature in a RF sputtering system at partial argon (Ar) pressure. A number of 10 films are deposited at 8 sccm of Ar pressure while varying the rf power from 90 to 360 watt. Besides, another set of 7 films are deposited at 240 watt RF power while varying the Ar pressure from 8 to 32 watts. All the films are characterized using FESEM, AFM, XRD, and four points probe. The analysis results substantiate that, to fabricate a low resistive thin layer of molybdenum (Mo) both sputtering power, and deposition time Ar pressure plays significant rules. It is found that, with the increase of the RF power (90 to 280 watt) the deposition rate increase from 1.2 A0/sec to 4.4 A0/sec. But at a RF power higher than 280 watt the deposition rate saturated and it does not increase as linear as before. Also resistivity continuously decreases as the RF power increases from 90 watt up to 270 watt, after that the resistivity remain almost same regardless the RF power increased. Besides, by varying the Ar pressure it is found that with the increase of the Ar pressure the deposition rate increase until 20 sccm (up to 2.4 A0/sec). With further increase of the Ar pressure deposition rate start reducing and reached 2.1 A0/sec at 32 sccm. Based on the above investigation and analysis optimized film is deposited and further analyzed. The surface roughness is analyzed using AFM characterization tool and found 27.4519 nm. The FESEM and XRD analysis along with the resistivity of the film is used to measure the strain of the deposited film and found a strain of less than 0.01% on the optimized film, which is essential for MEMS/NEMS device fabrication and energy harvesting applications.

Effect of Substrate Type on the Electrical and Optical Properties of Cold-sputtered Indium Tin Oxide Films as a function of Post-deposition Heat Treatment

2010 ◽  
Vol 1256 ◽  
Author(s):  
Salil Joshi ◽  
Gregory W. Book ◽  
Rosario A. Gerhardt
Keyword(s):  
Tin Oxide ◽  
Indium Tin Oxide ◽  
Visible Region ◽  
Rf Sputtering ◽  
Heat Treatments ◽  
Visible Absorption ◽  
Force Microscopy ◽  
Quartz Substrates ◽  
Post Deposition ◽  
Ito Films

AbstractIndium Tin Oxide (ITO) films were deposited by RF sputtering onto glass and quartz substrates with no external heating. An ITO target containing 10 wt% SnO2 was used for the deposition in a Kurt Lesker PVD75 system, in an atmosphere of 50% O2 + 50% Ar. Post-deposition heat treatments were done on these coatings at 150°C, 300°C and 450°C in an atmosphere of commercial air or argon. The effects of these heat treatments on the microstructure and the properties of the films were evaluated using atomic force microscopy, resistivity measurements, and UV-visible absorption spectroscopy. The heat treatments were observed to significantly affect the properties such as transmittance in the visible region, optical band gap and the electrical resistivity of the films. The main differences are caused by the differences in thermal expansion coefficient of the substrates as compared to the sputtered ITO films.

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