Quasi-monochromatic x-ray filter with thin film multilayer for a large area radiation field

2009 ◽  
Author(s):  
Youngsei Park ◽  
Sejin Han ◽  
Jangyeol Chae ◽  
Changkyu Kim ◽  
Kwon S. Chon ◽  
...  
Keyword(s):  
Thin Film ◽  
Radiation Field ◽  
Large Area ◽  
X Ray

Bio-mimetic integrated surface nano structures for medical imaging scintillation materials

2013 ◽  
Vol 1498 ◽  
pp. 15-19
Author(s):  
P. Pignalosa ◽  
B. Liu ◽  
W. Guo ◽  
X. Duan ◽  
Y. Yi
Keyword(s):  
Thin Film ◽  
Medical Imaging ◽  
Light Output ◽  
Proof Of Concept ◽  
Efficiency Enhancement ◽  
Large Area ◽  
X Ray ◽  
Nano Structures ◽  
Output Efficiency ◽  
Very High

ABSTRACTWe have improved bio-inspired Moth eye nanostructures to enhance the scintillator materials external quantum efficiency significantly. As a proof of concept, we have demonstrated very high light output efficiency enhancement for Lu2SiO5:Ce3+ (LSO:Ce) film in large area. The X-ray mammographic instrument was employed to demonstrate the light output enhancement of the Lu2SiO5:Ce thin film with bio-inspired Moth eye-like nano photonic structures. Our work could be extended to other thin film scintillator materials and is promising to achieve lower patient dose, higher resolution image of human organs and even smaller scale medical imaging.

Fabrication of large-area x-rays masks for UDXRL on beryllium using thin film UV lithography and x-ray backside exposure

2004 ◽  
Author(s):  
Josef Kouba ◽  
Zhong-Geng Ling ◽  
Lin Wang ◽  
Yohannes M. Desta ◽  
Jost Goettert
Keyword(s):  
Thin Film ◽  
X Rays ◽  
Large Area ◽  
X Ray ◽  
Uv Lithography ◽  
Area X

WE-G-110-04: Finding the Optimal Thickness of Large Area Thin-Film CdTe Detector under Diagnostic X-Ray Beams

2011 ◽  
Vol 38 (6Part33) ◽  
pp. 3833-3833
Author(s):  
X Jin ◽  
D Shvydka ◽  
E Parsai
Keyword(s):  
Thin Film ◽  
Optimal Thickness ◽  
Large Area ◽  
X Ray ◽  
Cdte Detector

Large Area Depositions of Si/SiC Quantum Well Films for Thermoelectric Generator Applications

2005 ◽  
Vol 886 ◽  
Author(s):  
Tianhua Yu ◽  
Harry Efstathiadis ◽  
Richard Matyi ◽  
Pradeep Haldar ◽  
Saeid Ghamaty ◽  
...  
Keyword(s):  
Thin Film ◽  
Quantum Well ◽  
Photoelectron Spectroscopy ◽  
High Efficiency ◽  
Waste Heat ◽  
Thermoelectric Devices ◽  
Electrical Measurements ◽  
Large Area ◽  
X Ray ◽  
Effective Manner

ABSTRACTRecent development in thermoelectric conversion, especially in the area of quantum well (QW) thin film materials, have demonstrated the potential to achieve the high efficiency and power density to fabricate future power supplies. In this study, we develop the large area QW films of N-type Si/SiC integrated with P-type B4C/B9C, which can be used as thermoelectric devices for waste heat recovery. The approach is to fabricate thick large area film stacks (up to 11 μm) deposited by sputter deposition technique on 6” n-type (100) silicon substrates, which might be proven to be a suitable method for potentially manufacturing large area thermoelectric devices in a cost effective manner. These more basic studies are being carried out to better understand variables such as film thickness, deposition rate and other important parameters of these ∼10 nm films. The resulting as deposited and annealed multilayer stacks were characterized in terms of thin film uniformity, thickness, growth rate, composition, and thermoelectric performance, by Spectroreflectometry, atomic force microscopy (AFM), Auger electron spectroscopy (AES), X-ray photoelectron spectroscopy (XPS), X-ray reflectivity (XRR), and electrical measurements. Issues, which could cause film stack degradation, such as interface layer formation, film delamination, and crack formation lowering the device performance will be presented and correlated to device efficiency.

Low-temperature solution-processed sol-gel K-rich KNN thin films for flexible electronics

MRS Advances ◽  
2018 ◽  
Vol 3 (5) ◽  
pp. 269-275 ◽  
Author(s):  
Rajinder Singh Deol ◽  
Meenal Mehra ◽  
Bhaskar Mitra ◽  
Madhusudan Singh
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Low Temperature ◽  
Sol Gel ◽  
Large Area ◽  
Solution Processed ◽  
X Ray ◽  
Force Microscopy ◽  
Temperature Solution ◽  
Piezoelectric Constants

ABSTRACTSputtered lead-free piezoelectric materials like potassium sodium niobate (K1-xNaxNbO3 or KNN) have received significant technological interest in recent years in light of several reports of piezoelectric constants comparable to lead zirconium titanate (PZT). Potential applications include self-powered sensors, actuators, and low acoustic impedance transducers. For large area printed applications, it is vital to develop low-temperature solution processed deposition methods. In this work, sol-gel synthesis of K-rich (70:30) KNN was carried out under an argon atmosphere, using acetate precursors, followed by precipitation of white KNN powder upon careful drying. Powder X-ray diffraction (XRD) scans of the product with a Cu Kα source after calcination revealed a dominant (110) peak, accompanied by smaller (100) and (010) peaks, in agreement with published standard KNN data. The composition of K-rich phase was confirmed using energy dispersive X-ray spectroscopy (EDX). To produce thin films, the sol was spin coated on a surface-treated Au-coated Si substrate, followed by slow annealing to obtain low surface roughness films (RMS roughness ﹤∼10 nm) of thickness ∼200 nm after solvent removal. Atomic force microscopy (AFM) scans revealed an unremarkable amorphous film. However, deposition of the sol on the Au-coated backside of Si wafer under similar processing conditions revealed limited polycrystalline film formation observed using optical profilometry. Thin film XRD measurements of the deposited film reveal orthorhombic phase growth of KNN, though the unannealed film was more amorphous than the calcined KNN film. Preliminary piezoresponse force microscopy (PFM) scans were used to estimate a piezoelectric constant (d33) ∼ 2.7 pC/N, consistent with the general expectation of lower piezoelectric constants for thin sol-gel films. The highest processing temperature used at any step during the deposition process was 90°C, consistent with the applications involving flexible polyimide substrates. This low-temperature thin-film growth suggests a potential route towards integration of large area piezoelectric generators for environmentally-friendly autonomous flexible sensor applications, with better control of phase and composition during the solution-phase deposition of KNN.

Process Integration of A-Si:H Schottky Diode and thin Film Transistor for Low-Energy X-Ray Imaging Applications

1998 ◽  
Vol 507 ◽  
Author(s):  
B. Park ◽  
R.V.R. Murthy ◽  
A. Sazonov ◽  
A. Nathan ◽  
S.G. Chamberlain
Keyword(s):  
Thin Film ◽  
Schottky Diode ◽  
Fill Factor ◽  
Process Integration ◽  
Thin Film Transistor ◽  
Sampling Period ◽  
Low Energy ◽  
Large Area ◽  
X Ray ◽  
X Ray Imaging

ABSTRACTIn this paper, we discuss the various design and fabrication issues related to the process integration of a molybdenum/amorphous silicon (Mo/a-Si:H) Schottky diode and a thin film transistor (TFT), for realization of an X-ray pixel intended for large area and low energy imaging applications. Here, the Schottky diode serves as the sensor and the TFT as a switching element for charge readout. Different pixel configurations are fabricated and compared taking into consideration design aspects such as leakage current, process sequence in terms of mask count, fill factor, and mechanical integrity of various layers. Preliminary X-ray response measurements, over the range (40 – 115) kVp, yield a pixel sensitivity of (1–10) million electrons for a readout sampling period of 16·7 ms.

Characteristics of dual-gate thin-film transistors for applications in digital radiology

1996 ◽  
Vol 74 (S1) ◽  
pp. 131-134 ◽  
Author(s):  
D. Waechter ◽  
Z. Huang ◽  
W. Zhao ◽  
I. Blevis ◽  
J. A. Rowlands
Keyword(s):  
Thin Film ◽  
Thin Film Transistors ◽  
Channel Length ◽  
Amorphous Selenium ◽  
Large Area ◽  
Digital Radiology ◽  
X Ray ◽  
Dual Gate ◽  
Gate Potential ◽  
Over The Top

A large-area flat-panel detector for digital radiology is being developed. The detector uses an array of dual-gate thin-film transistors (TFTs) to read out X-ray-generated charge produced in an amorphous selenium (a-Se) layer. The TFTs use CdSe as the semiconductor and use the bottom gate for row selection. The top gate can be divided into a "deliberate" gate, covering most of the channel length, and smaller "parasitic" gates that consist of (i) overlap of source or drain metal over the top-gate oxide, and (ii) gap regions in the metal that are covered only by the a-Se. In this paper we present the properties of dual-gate TFTs and examine the effect of both the deliberate and parasitic gates on the detector operation. Various options for controlling the top-gate potential are analyzed and discussed.

Determination of Stoichiometry of GaAs Component in (Gaas)Ge Epitaxially Grown Thin Films by Electron Microprobe X-Ray Analysis

1990 ◽  
Vol 48 (2) ◽  
pp. 264-265
Author(s):  
D. R. Liu ◽  
S. S. Shinozaki ◽  
R. J. Baird
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Compound Semiconductors ◽  
Energy Dispersive Analysis ◽  
X Ray ◽  
Metastable Alloys ◽  
Lower Voltage

The epitaxially grown (GaAs)Ge thin film has been arousing much interest because it is one of metastable alloys of III-V compound semiconductors with germanium and a possible candidate in optoelectronic applications. It is important to be able to accurately determine the composition of the film, particularly whether or not the GaAs component is in stoichiometry, but x-ray energy dispersive analysis (EDS) cannot meet this need. The thickness of the film is usually about 0.5-1.5 μm. If Kα peaks are used for quantification, the accelerating voltage must be more than 10 kV in order for these peaks to be excited. Under this voltage, the generation depth of x-ray photons approaches 1 μm, as evidenced by a Monte Carlo simulation and actual x-ray intensity measurement as discussed below. If a lower voltage is used to reduce the generation depth, their L peaks have to be used. But these L peaks actually are merged as one big hump simply because the atomic numbers of these three elements are relatively small and close together, and the EDS energy resolution is limited.

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