scholarly journals Substrate Rotation Chemical Bath Deposition of Cadmium Sulfide Buffer Layers for Thin Film Solar Cell Application

2013 ◽  
Vol 2013 ◽  
pp. 1-4 ◽  
Author(s):  
Kshitij Taneja ◽  
Alekhya Venkata Madiraju ◽  
Manoj Kumar ◽  
Raghunandan Seelaboyina ◽  
Anup Kumar Keshri ◽  
...  
Keyword(s):  
Cadmium Sulfide ◽  
Chemical Bath Deposition ◽  
Nir Spectroscopy ◽  
Buffer Layers ◽  
X Ray Diffraction ◽  
Solar Cell Application ◽  
Force Microscopy ◽  
Substrate Rotation ◽  
Atomic Force ◽  
20 Nm

A method for deposition of cadmium sulfide (CdS) buffer layer thin films on fluorine-doped tin oxide (FTO) glass, by chemical bath deposition (CBD), has been modified. For achieving relatively uniform and pin-hole-free CdS films, substrate rotation, concentration of CdS salts, and deposition time were optimized. The deposited films were characterized by UV-Vis-NIR spectroscopy, scanning electron microscopy (SEM), X-ray diffraction (XRD), and atomic force microscopy (AFM). Band gap of ~2.4 eV was measured by UV-Vis-NIR spectroscopy, CdS phase was confirmed by XRD, and film uniformity and roughness (~15–20 nm) were measured by SEM and AFM, respectively.

scholarly journals Dielectric Function of AlN Grown on Si (111) by MBE

1999 ◽  
Vol 572 ◽  
Author(s):  
Stefan Zollner ◽  
Atul Konkar ◽  
R. B. Gregory ◽  
S. R. Wilson ◽  
S. A. Nikishin ◽  
...  
Keyword(s):  
Molecular Beam ◽  
Buffer Layers ◽  
Two Dimensional ◽  
X Ray Diffraction ◽  
Growth Morphology ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Dimensional Growth ◽  
Peak Widths

ABSTRACTWe measured the ellipsometric response from 0.7–5.4 eV of c-axis oriented AlN on Si (111) grown by molecular beam epitaxy. We determine the film thicknesses and find that for our AlN the refractive index is about 5–10% lower than in bulk AlN single crystals. Most likely, this discrepancy is due to a low film density (compared to bulk AlN), based on measurements using Rutherford backscattering. The films were also characterized using atomic force microscopy and x-ray diffraction to study the growth morphology. We find that AlN can be grown on Si (111) without buffer layers resulting in truely two-dimensional growth, low surface roughness, and relatively narrow x-ray peak widths.

Mechanical Stress, Grain-boundary Relaxation, and Oxidation of Sputtered CuNi(Mn) Films

1999 ◽  
Vol 14 (4) ◽  
pp. 1286-1294 ◽  
Author(s):  
W. Brückner ◽  
W. Pitschke ◽  
S. Baunack ◽  
J. Thomas
Keyword(s):  
Grain Boundary ◽  
Microstructural Characterization ◽  
Excess Vacancy ◽  
X Ray Diffraction ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron ◽  
Boundary Relaxation ◽  
20 Nm ◽  
Atomic Rearrangement

This paper focuses on understanding stress development in CuNi42Mn1 thin films during annealing in Ar. In addition to stress-temperature measurements, resistance-temperature investigations and chemical and microstructural characterization by Auger electron spectroscopy, scanning and transmission electron microscopy, x-ray diffraction, and atomic force microscopy were also carried out. The films are polycrystalline with a grain size of 20 nm up to 450 °C. To explain the stress evolution above 120 °C, atomic rearrangement (excess-vacancy annihilation, grain-boundary relaxation, and shrinkage of grain-boundary voids) and oxidation were considered. Grain-boundary relaxation was found to be the dominating process up to 250–300 °C. A sharp transition from compressive to tensile stress between 300 and 380 °C is explained by the formation of a NiO surface layer due to reaction with the remaining oxygen in the Ar atmosphere. This oxidation is masking the inherent structural relaxation above 300 °C.

Growth of (0001) ZnO Thin Films on Sapphire

1996 ◽  
Vol 449 ◽  
Author(s):  
A. J. Drehman ◽  
P. W. Yip
Keyword(s):  
Surface Roughness ◽  
Buffer Layers ◽  
Zno Films ◽  
X Ray Diffraction ◽  
Axis Orientation ◽  
Force Microscopy ◽  
Sapphire Substrates ◽  
Atomic Force

ABSTRACTUsing reactive rf sputtering, we have grown (0001) oriented ZnO films in situ on heated c-axis sapphire substrates, that are promising, particularly in terms of surface roughness, as buffer layers for the subsequent epitaxial growth of III-V nitride films. We compare the effects of on-axis and off-axis sputter geometries on the film epitaxy and smoothness. We also examined the effect of substrate temperature on the growth and smoothness and quality of the film. X-ray diffraction was used to verify the hexagonal ZnO phase, its c-axis orientation and, qualitatively, the degree of its epitaxy. Atomic Force Microscopy (AFM) was used to determine the ZnO growth morphology and roughness. Our best films, obtained by off-axis sputter deposition, have a surface roughness of less than 1 nm.

Influence of Ammonia on the Fabrication of Aligned Carbon Nanotubes Using Thermal CVD

2011 ◽  
Vol 467-469 ◽  
pp. 312-315
Author(s):  
Gang Li ◽  
Wen Ming Cheng
Keyword(s):  
Carbon Nanotubes ◽  
Chemical Vapor ◽  
X Ray Diffraction ◽  
Vertical Alignment ◽  
X Ray ◽  
Force Microscopy ◽  
Si Substrates ◽  
Atomic Force ◽  
Aligned Carbon Nanotubes ◽  
20 Nm

Ultra-thin (20 nm) nickel catalyst films were deposited by sputtering on SiO2/Si substrates. At the pretreatments, ammonia (NH3) was conducted for different time in a thermal chemical vapor deposition (CVD) system. Pretreated samples were characterized using atomic force microscopy (AFM). After the pretreatment, acetylene was introduced into the chamber for 10 min, samples were characterized using scanning electron micrograph (SEM) and X-ray diffraction (XRD). It was concluded that NH3 pretreatment was very crucial to control the surface morphology of catalytic metals and thus to achieve the vertical alignment of carbon nanotubes (CNTs). With higher density of the Ni particles, better alignment of the CNTs can be obtained due to steric hindrance effect between neighboring CNTs.

Growth and Characterization of AlN and GaN Thin Films Deposited on Si(111) Substrates Containing a Very Thin Al Layer

2003 ◽  
Vol 798 ◽  
Author(s):  
Zachary J. Reitmeier ◽  
Robert F. Davis
Keyword(s):  
Flow Time ◽  
Buffer Layers ◽  
Nucleation Density ◽  
X Ray Diffraction ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Aln Buffer ◽  
Peak Widths

ABSTRACTAlN films and GaN films with AlN buffer layers were deposited via metalorganic vapor phase epitaxy on Si(111) substrates previously exposed to trimethylaluminum for increasing times. Atomic force microscopy (AFM) was used to determine the influence of Al pre-flow time on the nucleation and surface morphology of the AlN and GaN films. When preceded by a 10 second Al pre-flow, AlN films feature an increased and more uniform nucleation density as compared to films deposited without Al pre-flows. Ten second Al pre-flows were also found to result in a reduction of the RMS roughness for 100 nm thick AlN films from 3.6 nm to 1.0 nm. AFM of 0.5 μm thick GaN films deposited on AlN buffers with varying pre-flow times showed reduced roughness and decreased pit density when using Al pre-flows of 10 or 20 seconds. High resolution x-ray diffraction of the GaN films showed a reduction in the average full-width halfmaximum (FWHM) of the GaN (00.2) reflection from 1076 arcsec to 914 arcsec when the AlN buffer layer was initiated with a 10 second Al pre-flow. Increasing the pre-flow time to 20 seconds and 30 seconds resulted in average (00.2) FWHM values of 925 arcsec and 928 arcsec, respectively. Similar behavior of the peak widths was observed for the (30.2) and (10.3) reflections when the pre-flow times were varied from 0 to 30 seconds.

A Study of the Effect of Growth Rate and Annealing on GaN Buffer Layers on Sapphire

1995 ◽  
Vol 395 ◽  
Author(s):  
J.C. Ramer ◽  
K. Zheng ◽  
C.F. Kranenberg ◽  
M. Banas ◽  
S.D Hersee
Keyword(s):  
Growth Rate ◽  
Buffer Layer ◽  
Layer Growth ◽  
Buffer Layers ◽  
Degree Of Crystallinity ◽  
X Ray Diffraction ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Gan Buffer Layer

ABSTRACTUsing atomic force microscopy (AFM) and X-ray diffraction (XRD) we have determined that on [0001] oriented sapphire, the GaN buffer layer shows a degree of crystallinity that is dependent on growth rate. Annealing studies show evolution of the crystallinity and the emergence of a preferred orientation. Also, substrate orientation is found to influence the buffer layer crystallinity. Based on this work and previous results, we propose that the GaN buffer layer growth can be described by the Stranski-Krastanov growth process.

scholarly journals Deposition and characterization of Cu4SnS4 thin films by chemical bath deposition method

2010 ◽  
Vol 29 (1) ◽  
pp. 97 ◽  
Author(s):  
Anuar Kassim ◽  
Tan Wee Tee ◽  
Abdul Halim Abdullah ◽  
Saravanan Nagalingam ◽  
Ho Soon Min
Keyword(s):  
Thin Films ◽  
Atomic Force Microscopy ◽  
Chemical Bath Deposition ◽  
Chemical Bath Deposition Method ◽  
Oxide Glass ◽  
Deposition Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force

A low cost chemical bath deposition method has been used for the preparation of Cu4SnS4 thin films onto indium tin oxide glass substrate. The deposition parameters such as bath temperature (50 °C), deposition time (120 min), electrolyte concentration (0.05 M) and bath pH (1.5) were optimized to obtain good quality thin films. The structural, surface morphological and optical properties of thin films were studied by X-ray diffraction, an atomic force microscopy and an UV-Vis Spectrophotometer, respectively. The X-ray diffraction study revealed that the Cu4SnS4 films were polycrystalline in nature with the preferential orientation along the (221) plane. The atomic force microscopy results indicated that the films were smooth, uniform and the substrate surface was covered completely at these experimental conditions. These films exhibited p-type semiconductor behavior with the band gap energy about 1.57 eV.

scholarly journals PREPARATION AND CHARACTERIZATION OF IRON SULPHIDE THIN FILMS BY CHEMICAL BATH DEPOSITION METHOD

2010 ◽  
Vol 10 (1) ◽  
pp. 8-11 ◽  
Author(s):  
Anuar Kassim ◽  
Tan WeeTee ◽  
Dzulkefly Kuang Abdullah ◽  
Atan Mohd. Sharif ◽  
Ho SoonMin ◽  
...  
Keyword(s):  
Thin Films ◽  
Atomic Force Microscopy ◽  
Band Gap ◽  
Chemical Bath Deposition ◽  
Substrate Surface ◽  
Morphological Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force

FeS2 thin films have been deposited by using low cost chemical bath deposition technique. The films obtained under deposition parameters such as bath temperature (90 °C), deposition period (90 min), electrolyte concentration (0.15 M) and pH of the reactive mixture (pH 2.5). The thin films were characterized using X-ray diffraction and atomic force microscopy in order to study the structural and morphological properties. The band gap energy, transition type and absorption properties were determined using UV-Vis Spectrophotometer. X-ray diffraction displayed a pattern consistent with the formation of an orthorhombic structure, with a strong (110) preferred orientation. Atomic force microscopy image showed the substrate surface is well covered with irregular grains. A direct band gap of 1.85 eV was obtained according to optical absorption studies.   Keywords: Iron sulfide, X-ray diffraction, chemical bath deposition, thin films

Ordered nanostructure of single-crystalline GaN nanowires in a honeycomb structure of anodic alumina

2000 ◽  
Vol 15 (2) ◽  
pp. 347-350 ◽  
Author(s):  
G. S. Cheng ◽  
L. D. Zhang ◽  
S. H. Chen ◽  
Y. Li ◽  
L. Li ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Honeycomb Structure ◽  
Anodic Alumina ◽  
X Ray Diffraction ◽  
Single Crystalline ◽  
Force Microscopy ◽  
Gan Nanowires ◽  
Atomic Force ◽  
Transmission Electron ◽  
20 Nm

Ordered nanostructure of single-crystalline GaN nanowires in a honeycomb structure of anodic alumina was synthesized through a gas reaction of Ga2O vapor with a constant ammonia atmosphere at 1273 K in the presence of nano-sized metallic indium catalysis. Atomic force microscopy, x-ray diffraction, Raman backscattering spectroscopy, scanning electron microscopy, and transmission electron microscopy indicate that the ordered nanostructure consists of single-crystalline hexagonal wurtzite GaN nanowires in the uniform pores of anodic alumina about 20 nm in diameter and 40–50 μm in length. The growth mechanism of the ordered nanostructure is discussed. The photoluminescence spectrum of this nanostructure is also reported.

scholarly journals The effect of periodic silane burst on the properties of GaN on Si (111) substrates

2004 ◽  
Vol 831 ◽  
Author(s):  
K. Y. Zang ◽  
S. J. Chua ◽  
C. V. Thompson ◽  
L. S. Wang ◽  
S. Tripathy ◽  
...  
Keyword(s):  
Chemical Vapor ◽  
Buffer Layers ◽  
Threading Dislocation ◽  
X Ray Diffraction ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron ◽  
Dislocation Densities ◽  
Gan On Si ◽  
Aln Buffer

ABSTRACTThe periodic silane burst technique was employed during metalorganic chemical vapor deposition of epitaxial GaN on AlN buffer layers grown on Si (111). Periodic silicon delta doping during growth of both the AlN and GaN layers led to growth of GaN films with decreased tensile stresses and decreased threading dislocation densities, as well as films with improved quality as indicated by x-ray diffraction, micro-Raman spectroscopy, atomic force microscopy, and transmission electron microscopy. The possible mechanism of the reduction of tensile stress and the dislocation density is discussed in the paper.

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