Studies on the effects of Cd ion sources and chelating reagents on atomic layer Cds deposition by successive ionic layer adsorption and reaction (SILAR) method

CdS thin films were fabricated on an ITO-covered glass substrate by successive ionic layer adsorption and reaction (SILAR) method under various conditions. By changing Cd ion sources, chelating reagents, and pH, the obtained films were evaluated by their thickness, crystallinity, crystallite size, surface roughness, and elemental composition. CdCl2 and triethanolamine were found to provide the most well crystallized thick film among six Cd salts and six chelating reagents. In the present study, no marked effect of pH on the film quality was observed compared to the effect of the difference in the counter ions. The effects of counter ions, chelating reagents, and pH could be explained by the discussion in terms of the stability constant of Cd2+ for these chemical species and SH-

Electrochemical evaluation of the roles of chelating reagents in Cd ion adsorption on CdS surface for the successive ionic layer adsorption and reaction (SILAR) deposition

We evaluated the effect of the chelating reagents in the SILAR (successive ionic layer adsorption and reaction) process by monitoring the formation of one layer of CdS on S surface of the CdS layers prepared by successive UPD (under potential deposition) method. Anodic stripping voltammetry was adopted to measure the amount of CdS deposited on Au substrate. Among the chelating reagents examined, the under of the ability to enhance the depusitiun by dipping was cysteine > (None) > mercaptoethylamine > triethanolamine >> ethylenediamine. Considering the stability constant of the chelating reagents to Cd ions, the present experimental result showed that tight binding of Cd atoms to the surface S atoms is an important step in the deposition of CdS by SILAR method

The effect of chelating reagents on the layer-by-layer formation of CdS films in the electroless and electrochemical deposition processes

Triethanolamine (TEOA) and cysteine (Cys) were examined fur the effect of chelating reagents to deposit CdS thin films by means of two different processes. Those are the successive ionic layer adsorption and reaction (SILAR) method and the successive under potential deposition (UPD) method, in which Cd and S are separately deposited on a polycrystalline Au substrate from each solution. Evaluation by stripping voltammetry showed that the amount of the deposited CdS was increased for 1, 3, 5, 7, and 10 layers of CdS prepared by these methods. It was found that, with the SILAR method, the order of the ability to increase CdS depositiun was Cys>TEOA>None. On the other hand, with the successive UPD method, the order was None≥TEOA>Cys, showing a certain inhibition in the electrochemical deposition process. It is concluded that CdS deposition by the SILAR method becomes compatible to the successive UPD when a suitable chelating reagent was added to the Cd solution

Effect of Cadmium Precursor Solutions on Fabrication of CdS Thin Films by Successive Ionic Layer Adsorption and Reaction (SILAR) Technique

CdS thin films were fabricated on ITO-covered glass by successive ionic layer adsorption and reaction (SILAR) technique. The thickness of the CdS thin films increased with increasing the number of SILAR cycles. However, it was about 1/3 of the thickness expected from the ideal deposition process. The surface roughness increased as growth of CdS thin films. To increase the film thickness and to reduce the film roughness, we tried to change counter ions of cadmium ion source solution and to add chelating agent to the solution. In case of using CdC12 and triethanolamine, the film thickness was increased and the surface roughness was reduced

Clinical characteristics of acromegalic patients with empty sella and their outcomes following transsphenoidal surgery

Purpose: To analyze the clinical characteristics of acromegalic patients with empty sella (ES, herniation of the subarachnoid space within the sella turcica) and the impact of ES on transsphenoidal surgery in such patients. Methods: Seventy-eight patients, newly diagnosed with acromegaly who underwent transsphenoidal surgery were included. ES was defined as the pituitary gland and adenoma occupying less than 50% of the sella turcica on midsagittal magnetic resonance (MR) imaging. Results: Twelve patients (15.4%), predominantly female (10 women, p = .047), had ES in preoperative MR imaging. ES patients had smaller mean tumor diameter (6.3 mm) than non-ES patients (11.2 mm, p = .001). In preoperative MR imaging, occult adenoma was found in three (25%) ES and three (4.5%) non-ES patients (p = .044). Intraoperative cerebrospinal fluid (CSF) leakage was more frequent in the ES patients than in the non-ES patients (58.3 vs. 25.8%, p = .024). This led to an increased rate of sellar floor reconstruction using abdominal fat and/or postoperative lumber drainage in the ES patients (ES: 41.7 vs. non-ES: 16.7%, p = .063). Endocrinological remission after surgery was more frequent in the non-ES patients (72.7%) than in the ES patients (58.3%) (p = .248). Conclusions: Co-existence of acromegaly with ES is not rare, and is associated with occult adenoma, intra/postoperative CSF leakage, and a worse endocrinological outcome after transsphenoidal surgery; although, the underlying mechanism remains unclear. © 2017 Springer Science+Business Media New YorkEmbargo Period 12 month