Showing papers on "Chemical bath deposition published in 1995"
TL;DR: In this article, chemical bath deposition of chalcogenide semiconductors (CdS, ZnS, CdSe) was investigated and the relationship between the growth mechanism and the structure of the films was established from Transmission Electron Microscopy (TEM) and High Resolution TEM measurements.
117 citations
TL;DR: In this article, a better understanding of the correlations between the deposition parameters (temperature, bath composition) and epitaxial quality is obtained by using electron diffraction and transmission techniques, x-ray diffraction, in combination with Raman spectroscopy.
Abstract: Epitaxial growth of cadmium sulfide on InP single crystals is achieved by chemical bath deposition (CBD) in ammonia solutions at near room temperature. A better understanding of the correlations between the deposition parameters (temperature, bath composition) and the epitaxial quality is obtained by using electron diffraction and transmission techniques, x-ray diffraction, in combination with Raman spectroscopy. They are supplemented by electrochemical impedance and photocurrent experiments which give information on energetic structures between InP and CBD-CdS. Direct relations between the substrate properties and the growth habits of the CdS film (hexagonal vs. cubic, epitaxial vs. polycrystalline) are found.
93 citations
TL;DR: In this paper, thin films of monophasic crystalline hexagonal ZnO were deposited from solutions of zinc acetate in the presence of ethylenediamine and sodium hydroxide onto glass microscope slides.
92 citations
TL;DR: In this article, a chemical bath deposition of Cd1 − xZnxS thin films has been attempted following the usual methods employed for the chemical bath depos of cdS and ZnS. The results showed that the films obtained show compositions which vary almost linearly with the bath composition variation.
84 citations
TL;DR: In this paper, photoacoustic spectroscopy was used to study the band-gap shift effect of CdS films, which were grown by chemical bath deposition and exposed to different annealing atmospheres over a range of temperature.
Abstract: We study by photoacoustic spectroscopy the band‐gap shift effect of CdS films. The CdS films were grown by chemical bath deposition and exposed to different annealing atmospheres over a range of temperature in which the sample structure changes. We show the band‐gap evolution and resistivity as a function of temperature of thermal annealing and determine the process that produces the best combination of high band‐gap energy and low resistivity.
72 citations
TL;DR: In this article, the structural, optical, chemical, and electrical properties of the ZnSe thin-films deposited by this method have been studied and the effect of various process parameters on the growth and the film quality is presented.
Abstract: Chemical-bath deposition of ZnSe thin films from NH{sub 3}/NH{sub 2}-NH{sub 2}/SeC(NH{sub 2}){sub 2}/Na{sub 2}SO{sub 3}/ZnSO{sub 4} solutions has been studied. The effect of various process parameters on the growth and the film quality is presented. A first approach to a mechanistic interpretation of the chemical process, based on the influence of the process parameters on the film growth rate, is reported. The structural, optical, chemical, and electrical properties of the ZnSe thin-films deposited by this method have been studied. The electron diffraction (EDS) analysis shows that the films are microcrystalline with mixed cubic and hexagonal structure. EDS analysis has demonstrated that the films are highly stoichiometric. Scanning electron microscopy, atomic force microscopy, and X-ray photoelectron spectroscopy studies of the ZnSe thin films deposited by this method show that the films are continuous and homogeneous. Optical measurements have allowed the authors to detect the presence of the spin-orbit splitting effect in this material. Electrical conductivity measurements have shown the highly resistive nature of these films ({rho} {approximately} 10{sup 9} {Omega} cm).
71 citations
TL;DR: In this paper, the conduction band offset in a solar cell quality junction formed by chemical bath deposition of CdS on a polycrystalline thin film of Cu(In,Ga)Se2 was derived.
Abstract: Contact potential difference measurements in the dark and under illumination are used to derive the conduction band offset (ΔEc) in a solar cell quality junction formed by chemical bath deposition of CdS on a polycrystalline thin film of Cu(In,Ga)Se2. Our experimental measurements and the estimates made for dipole contributions show that the junction is of type II, i.e., without a spike in the conduction band ( ΔEc=80 meV±100 meV). This is consistent with the high performance of the actual solar cell. However, it differs from most previous results on junctions based on single crystals and/or vacuum deposited CdS, which indicated the existence of a conduction band spike.
60 citations
TL;DR: In this paper, the epitaxial properties of CdTe films were characterized using Reflexion high-energy electron diffraction and five-circle x-ray diffraction techniques, with a growth rate of about 0.7 μm h−1.
Abstract: Epitaxial (111) CdTe films have been grown on (1 1 1) InP single crystals by one step electrodeposition in aqueous acidic solution, at a temperature of 85 °C, and a growth rate of about 0.7 μm h−1. Reflexion high‐energy electron diffraction and five‐circle x‐ray diffraction techniques have been used to characterize the interface structure and epitaxial quality. The epitaxy of CdTe (fcc a=6.49 A) takes place with a direct continuation of the InP lattice (fcc a=5.87 A), with no rotation of the respective crystallographic directions. The epitaxy is markedly improved when the InP substrate is covered with a thin film (20–30 nm) of epitaxial CdS grown by chemical bath deposition which acts as an interfacial buffer layer.
57 citations
TL;DR: In this article, Cadmium sulfide thin films were deposited on polyester foils (PE) by chemical bath deposition using triethanolamine (TEA) and citrate (Citrate) as ligand for complexation with cadmium ions.
32 citations
TL;DR: In this article, the chemical bath deposition of CdSe layers from cadmium acetate + sodium selenosulfite solutions was studied by means of quartz crystal microbalance (QCM) experiments, combined with electron microscopy observations and energy-dispersive X-ray analysis.
22 citations
TL;DR: In this paper, the n + -type porous Si-polyaniline (PAn) heterojunction was characterized by XPS depth profiling analysis, where the PS columns are sheathed by 2 PAn layers and the Si pores are totally filled with 5 PAN layers.
TL;DR: In this article, electron probe microanalysis (EPMA) and X-ray photoemission spectroscopy (XPS) were used to study CdS thin films grown from an aqueous solution of iodides.
Abstract: CdS thin films grown from an aqueous solution of iodides were studied using electron probe microanalysis (EPMA) and X-ray photoemission spectroscopy (XPS). It has been revealed that the films contain 3% iodine whereas those grown from chlorides contain less than 1% chlorine. Both films are Cd-rich and also have impurity phases of CdOx and/or Cd(OH)x. XPS depth profile showed a uniform distribution of these impurities in the films. The presence of iodine in the former CdS film, which is suitable for CdS/CuInS2 solar cell application, suggests a potential role of iodine in the improvement of the solar cell performance.
09 May 1995
TL;DR: In this paper, the use of CdS interlayers grown by chemical bath deposition (CBD) was investigated on a wide variety of III-V semiconductors.
Abstract: We have investigated the use of CdS interlayers grown by chemical bath deposition (CBD). We have deposited CdS on a wide variety of III-V semiconductors. We found that native oxides were reduced by the CdS treatment. CdS-treated and untreated HEMTs and metal-semiconductor-metal photodetectors (MSMs) were compared. Thin 50 /spl Aring/ layers were effective in reducing gate and surface leakage. The thin CdS layers reduced the gate leakage of InA1As/InGaAs HEMTs and the dark current of InA1As/InGaAs optical detectors. X-ray photoelectron spectroscopy indicates a reduction of surface oxides and the prevention of subsequent group III or V oxide formation. Backside processing of InGaAs/lnA1As MSMs allows complete coverage of the mesas. The CBD process for depositing CdS is inherently adaptable to a wide range of optoelectronic device processes.
Patent•
29 Sep 1995
TL;DR: In this paper, a process for manufacturing micromechanical parts having a diamond part consisting at least a tip (3a), wherein a substrate is prepared (8a) to form an impression (13a) of the desired shape of the diamond portion; the diamond part is carried out by chemical bath deposition of diamond vapor phase in the cavity and is then separated from the substrate.
Abstract: A process for manufacturing micromechanical parts having a diamond part consisting at least a tip (3a), wherein a substrate is prepared (8a) to form an impression (13a) of the desired shape of the diamond portion; the diamond part is carried out by chemical bath deposition of the diamond vapor phase in the cavity and is then separated from the substrate. To achieve the diamond in part, before the chemical vapor deposition, is deposited on the substrate, on the surface of the impression (13a), a primary layer of fine diamond particles of less than 10 nm diameter, suitable for act as seeds for diamond growth; is then made to grow the diamond layer by a vapor deposition; and the substrate (8a) is then at least partially removed.
TL;DR: In this article, CdS thin films from a solution containing cadmium acetate, thiourea, ammonia, and ammonium acyclic acid were prepared.
Abstract: We prepared CdS thin films from a solution containing cadmium acetate, thiourea, ammonia, and ammonium acetate. We varied fabrication conditions such as the concentrations of reactants, reaction temperature, and heat treatment, to investigate the changes in structural and optical properties of the film. Effects of substrate on the properties were also investigated.
TL;DR: In this paper, the effect of air annealing on the electrical resistivity of Cu1.9Se thin films grown by chemical bath deposition method has been studied in the temperature range 100-500 degrees C.
Abstract: Effect of air annealing on the electrical resistivity of Cu1.9Se thin films grown by chemical bath deposition method has been studied in the temperature range 100-500 degrees C. It was found that resistivity initially increases and reaches a maximum value of 1.6 Omega cm at around 250 degrees C, beyond which it decreases. The mechanism responsible for the observed resistivity behaviour has been explained by a combination of electron paramagnetic resonance absorption and transmission electron diffraction measurements.
Posted Content•
TL;DR: In this article, photoacoustic spectroscopy was used to study the band-gap shift effect of CdS/CdTe solar cells with high-quantum efficiency.
Abstract: We study by photoacoustic spectroscopy the band--gap shift effect of CdS films The CdS films were grown by chemical bath deposition and exposed to different annealing atmospheres over a range of temperature in which the sample structure is observed to change We show the band--gap evolution as a function of temperature of thermal annealing and determine the process which produces the best combination of high band--gap energy and low resistivity It allows us to know a possible procedure to obtain low--resistivity CdS/CdTe solar cells with high--quantum efficiency
TL;DR: In this article, the structural and optoelectronic properties of polycrystalline CdS films, fabricated by three different methods, are compared to one another for the purpose of preparing CdTe/CdS solar cells.
Abstract: The structural and optoelectronic properties of polycrystalline CdS films, fabricated by three different methods, are compared to one another for the purpose of preparing CdTe/CdS solar cells. The three methods were: alternated spraying of cation and anion solution at room temperature, spray pyrolysis, and chemical bath deposition. We studied the surface morphology and crystal quality and texture by scanning electron and optical microscopy and x-ray diffraction. All films had a well-developed wurtzite structure. Films grown by the alternated-spray method and the chemical bath method consist of randomly-oriented crystallites with dimensions direction. For growth by pyrolysis at 500°C, the surface is rough on a lateral scale of 0.1 to 0.3 microns.
23 Aug 1995
TL;DR: In this paper, the authors presented methods for preparing good quality CdS and CdSe thin films of 0.1 - 0.7 micrometer thickness from solutions at 24 - 50 degree(s)C containing citratocadmium(II) ions and thiourea.
Abstract: Methods for preparing good quality CdS and CdSe thin films of 0.1 - 0.7 micrometer thickness from solutions at 24 - 50 degree(s)C containing citratocadmium(II) ions and thiourea (for CdS) or N, N-dimethyl selenourea (for CdSe) are presented. The as prepared CdS thin films are photosensitive showing photo- to dark-conductivity ratio (S) of > 106 under AM-2 illumination. Annealing of these films at 400 - 450 degree(s)C for a few minutes converts them to n-type through partial conversion of the films to nonstoichiometric CdO. In the case of CdSe, such annealing improves the photosensitivity of the films from S equals 10 (as prepared) to greater than 107 (after annealing) under AM-2 illumination. Either film can be converted to n-type with dark conductivities of greater than 1 (Omega) -1 cm-1 and S equals 1 to 10 under AM-2 illumination using a post deposition treatment in dilute (0.01 - 0.05 M) HgCl2 solution followed by heating at 200 degree(s)C.© (1995) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
TL;DR: In this paper, the structural, optical, chemical, and electrical properties of the ZnSe thin-films deposited by this method have been studied and the effect of various process parameters on the growth and the film quality is presented.
Abstract: Chemical-bath deposition of ZnSe thin films from NH{sub 3}/NH{sub 2}-NH{sub 2}/SeC(NH{sub 2}){sub 2}/Na{sub 2}SO{sub 3}/ZnSO{sub 4} solutions has been studied. The effect of various process parameters on the growth and the film quality is presented. A first approach to a mechanistic interpretation of the chemical process, based on the influence of the process parameters on the film growth rate, is reported. The structural, optical, chemical, and electrical properties of the ZnSe thin-films deposited by this method have been studied. The electron diffraction (EDS) analysis shows that the films are microcrystalline with mixed cubic and hexagonal structure. EDS analysis has demonstrated that the films are highly stoichiometric. Scanning electron microscopy, atomic force microscopy, and X-ray photoelectron spectroscopy studies of the ZnSe thin films deposited by this method show that the films are continuous and homogeneous. Optical measurements have allowed the authors to detect the presence of the spin-orbit splitting effect in this material. Electrical conductivity measurements have shown the highly resistive nature of these films ({rho} {approximately} 10{sup 9} {Omega} cm).