Intermixing at the heterointerface between ZnS Zn S,O bilayer buffer and CuInS2 thin film solar cell absorber

The application of Zn compounds as buffer layers was recently extended to wide gap CuInS2 CIS based thin film solar cells. Using a new chemical deposition route for the buffer preparation aiming at the deposition of a single layer, nominal ZnS buffer without the need for any toxic reactants such as, e.g. hydrazine has helped to achieve a similar efficiency as respective CdS buffered reference devices. After identifying the deposited Zn compound, as ZnS Zn S,O bi layer buffer in former investigations [M. Bär, A. Ennaoui, J. Klaer, T. Kropp, R. S ez Araoz, N. Allsop, I. Lauermann, H. W. Schock, and M.C. Lux Steiner, Formation of a ZnS Zn S,O bilayer buffer on CuInS2 thin film solar cell absorbers by chemical bath deposition , J. Appl. Phys., accepted.], this time the focus lies on potential diffusion intermixing processes at the buffer absorber interface possibly, clarifying the effect of the heat treatment, which drastically enhances the device performance of respective final solar cells. The interface formation was investigated by x ray photoelectron and x ray excited Auger electron spectroscopy. In addition, photoelectron spectroscopy PES measurements were also conducted using tuneable monochromatized synchrotron radiation in order to gain depth resolved information. The buffer side of the buffer absorber heterointerface were investigated by means of the characterization of Zn S,O ZnS CIS structures where the ZnS Zn S,O bi layer buffer was deposited successively by different deposition times. In order to make the in terms of PES information depth deeply buried absorber side of the buffer absorber heterointerface accessible for characterization, in these cases the buffer layer was etched away by dilute HClaq. We found that while out leached Cu from the absorber layer forms together with the educts in the chemical bath a Zn 1 Z ,Cu2Z S like interlayer between buffer and absorber, Zn is incorporated in the uppermost region of the absorber. Both effects are strongly enhanced by postannealing the Zn S,O ZnS CIS samples. However, it was determined that the major fraction of the Cu and Zn can be found quite close to the heterointerface in the buffer and absorber layer, respectively. Due to this limited in the range of one monolayer spatial extent, these diffusion mechanisms were rather interpreted as a CBD induced and heat treatment promoted Cu Zn ion exchange at the buffer absorber interface. Possible impacts of this intermixing on the performance of the final solar cell devices will also be discusse

Diagnostic A-Scan of Choroidal Melanoma: Automated Quantification of Parameters

&lt;b&gt;&lt;i&gt;Aim:&lt;/i&gt;&lt;/b&gt; To develop an automated algorithm to quantify ultrasonographic A-scan parameters of choroidal melanoma. &lt;b&gt;&lt;i&gt;Methods:&lt;/i&gt;&lt;/b&gt; The study included 100 consecutive patients with a clinical diagnosis of choroidal melanoma. Ultrasonographic A-scans (8 MHz, 1,550 m/s, tissue sensitivity = 67 dB) were performed by standard techniques. We created and then utilized a MATLAB® script to generate four quantifiable A-scan parameters: (1) tumor height (mm), (2) the number of internal reflectivity peaks (numerical value), (3) median internal reflectivity (%), and (4) angle κ (°). &lt;b&gt;&lt;i&gt;Results:&lt;/i&gt;&lt;/b&gt; There were small (≤2.5 mm, &lt;i&gt;n&lt;/i&gt; = 32), medium (2.6–10.0 mm, &lt;i&gt;n&lt;/i&gt; = 53), and large (&amp;#x3e; 10.0 mm, &lt;i&gt;n&lt;/i&gt; = 14) tumors. The mean number of internal reflectivity peaks counted between the two tumor boundary spikes (surface and base) was 10.0 (σ = 8.7, range 1–37). The median value of the internal reflectivity peaks for all cases varied from 19.8 to 99.5 (mean = 68.3, σ = 20.5). A statistically significant correlation was observed between the tumor height categories and each of the three A-scan parameters: the number of internal reflectivity peaks (ρ = 0.90, &lt;i&gt;p&lt;/i&gt; &amp;#x3c; 0.01), median internal reflectivity (ρ = –0.63, &lt;i&gt;p&lt;/i&gt; &amp;#x3c; 0.01), and a positive angle κ (ρ = –0.32, &lt;i&gt;p&lt;/i&gt; = 0.03). &lt;b&gt;&lt;i&gt;Conclusions:&lt;/i&gt;&lt;/b&gt; An automated algorithm can provide quantifiable A-scan parameters for choroidal melanoma.</jats:p

Prospective two year follow up study comparing novel and conventional imaging procedures in patients with arthritic finger joints

Objective: To carry out a prospective two year follow up study comparing conventional radiography, three-phase bone scintigraphy, ultrasonography (US), and three dimensional (3D) magnetic resonance imaging (MRI) with precontrast and dynamic postcontrast examination in detecting early arthritis. The aim of the follow up study was to monitor the course of erosions during treatment with disease modifying antirheumatic drugs by different modalities and to determine whether the radiographically occult changes like erosive bone lesions of the finger joints detected by MRI and US in the initial study would show up on conventional radiographs two years later. Additionally, to study the course of soft tissue lesions depicted in the initial study in comparison with the clinical findings. Methods: The metacarpophalangeal, proximal interphalangeal, and distal interphalangeal joints (14 joints) of the clinically more severely affected hand (soft tissue swelling and joint tenderness) as determined in the initial study of 49 patients with various forms of arthritis were examined twice. The patients had initially been divided into two groups. The follow up group I included 28 subjects (392 joints) without radiographic signs of destructive arthritis (Larsen grades 0–1) of the investigated hand and wrist, and group II (control group) included 21 patients (294 joints) with radiographs showing erosions (Larsen grade 2) of the investigated hand or wrist, or both, at the initial examination. Results: (1) Radiography at the two year follow up detected only two erosions (two patients) in group I and 10 (nine patients) additional erosions in group II. Initial MRI had already detected both erosions in group I and seven (seven patients) of the 10 erosions in group II. Initial US had depicted one erosion in group I and four of the 10 erosions in group II. (2) In contrast with conventional radiography, 3D MRI and US demonstrated an increase in erosions in comparison with the initial investigation. (3) The abnormal findings detected by scintigraphy were decreased at the two year follow up. (4) Both groups showed a marked clinical improvement of synovitis and tenosynovitis, as also shown by MRI and US. (5) There was a striking discrepancy between the decrease in the soft tissue lesions as demonstrated by clinical findings, MRI, and US, and the significant increase in erosive bone lesions, which were primarily evident at MRI and US. Conclusions: Despite clinical improvement and a regression of inflammatory soft tissue lesions, erosive bone lesions were increased at the two year follow up, which were more pronounced with 3D MRI and less pronounced with US. The results of our study suggest that owing to the inadequate depiction of erosions and soft tissue lesions, conventional radiography alone has limitations in the intermediate term follow up of treatment. US has a high sensitivity for depicting inflammatory soft tissue lesions, but dynamic 3D MRI is more sensitive in differentiating minute erosions

Uveal Melanoma Regression after Brachytherapy: Relationship with Chromosome 3 Monosomy Status

&lt;b&gt;&lt;i&gt;Aim:&lt;/i&gt;&lt;/b&gt; The objective was to evaluate the relationship between the regression rate of ciliary body melanoma and choroidal melanoma after brachytherapy and chromosome 3 monosomy status. &lt;b&gt;&lt;i&gt;Methods:&lt;/i&gt;&lt;/b&gt; We conducted a prospective and consecutive case series of patients who underwent biopsy and brachytherapy for ciliary/choroidal melanoma. Tumor biopsy performed at the time of radiation plaque placement was analyzed with fluorescence in situ hybridization to determine the percentage of tumor cells with chromosome 3 monosomy. The regression rate was calculated as the percent change in tumor height at months 3, 6, and 12. The relationship between regression rate and tumor location, initial tumor height, and chromosome 3 monosomy (percentage) was assessed by univariate linear regression (R version 3.1.0). &lt;b&gt;&lt;i&gt;Results:&lt;/i&gt;&lt;/b&gt; Of the 75 patients included in the study, 8 had ciliary body melanoma, and 67 were choroidal melanomas. The mean tumor height at the time of diagnosis was 5.2 mm (range: 1.90-13.00). The percentage composition of chromosome 3 monosomy ranged from 0-20% (n = 35) to 81-100% (n = 40). The regression of tumor height at months 3, 6, and 12 did not statistically correlate with tumor location (ciliary or choroidal), initial tumor height, or chromosome 3 monosomy (percentage). &lt;b&gt;&lt;i&gt;Conclusion:&lt;/i&gt;&lt;/b&gt; The regression rate of choroidal melanoma following brachytherapy did not correlate with chromosome 3 monosomy status.</jats:p