Improvement of Indirect X-ray Detector Performance by Applying Additive Solvent to the Organic Active-Layer

2021 ◽  
Vol 21 (5) ◽  
pp. 2998-3003
Author(s):  
Jongkyu Won ◽  
Hailiang Liu ◽  
Jungwon Kang
Keyword(s):  
Active Layer ◽  
Mixing Condition ◽  
Detector Performance ◽  
X Ray ◽  
Active Layers ◽  
Layer Solution

In this paper, we studied how the sensitivity of an indirect X-ray detector was changed by adding the additive solvent DIO to the organic active-layers, such as P3HT:PCBM and PBDB-T:PCBM. The crystallinity and absorbance of the active-layer films were compared with different additive DIO contents. In both active-layers, the highest crystallinity and absorbance were obtained when 3 v% of the DIO was mixed with the active-layer solution. At the same mixing condition of the DIO, the highest sensitivity, of 1.17 mA/Gy · cm2, was obtained for the P3HT:PCBM detector, and the highest sensitivity, 1.87 mA/Gy · cm2, was obtained for the PBDB-T:PCBM detector. Compared to the detector without the DIO, the sensitivities of the detectors with the P3HT:PCBM and PBDB-T:PCBM increased by 18.12% and 20.27%, respectively.

High-purity Ge x-ray detectors: Sensitivity factors and usefulness

1990 ◽  
Vol 48 (2) ◽  
pp. 548-548
Author(s):  
E. B. Steel
Keyword(s):  
High Purity ◽  
High Energy ◽  
Quantitative Chemical Analysis ◽  
Detector Performance ◽  
X Ray ◽  
Detector Sensitivity ◽  
Specimen Holder ◽  
Many Instruments ◽  
Charge Resolution ◽  
Sensitivity Factors

High Purity Germanium (HPGe) x-ray detectors are now commercially available for the analytical electron microscope (AEM). The detectors have superior efficiency at high x-ray energies and superior resolution compared to traditional lithium-drifted silicon [Si(Li)] detectors. However, just as for the Si(Li), the use of the HPGe detectors requires the determination of sensitivity factors for the quantitative chemical analysis of specimens in the AEM. Detector performance, including incomplete charge, resolution, and durability has been compared to a first generation detector. Sensitivity factors for many elements with atomic numbers 10 through 92 have been determined at 100, 200, and 300 keV. This data is compared to Si(Li) detector sensitivity factors.The overall sensitivity and utility of high energy K-lines are reviewed and discussed. Many instruments have one or more high energy K-line backgrounds that will affect specific analytes. One detector-instrument-specimen holder combination had a consistent Pb K-line background while another had a W K-line background.

Vertically Optimized Phase Separation with Improved Exciton Diffusion Enables High-Efficiency Organic Solar Cells with Thick Active Layers

2021 ◽  
Author(s):  
Yanming Sun ◽  
Yunhao Cai ◽  
Qian Li ◽  
Guanyu Lu ◽  
Hwa Sook Ryu ◽  
...  
Keyword(s):  
Solar Cells ◽  
Phase Separation ◽  
Active Layer ◽  
Organic Solar Cells ◽  
High Efficiency ◽  
Diffusion Length ◽  
Active Layer Thickness ◽  
Exciton Diffusion ◽  
Exciton Diffusion Length ◽  
Active Layers

Abstract The development of high-performance organic solar cells (OSCs) with thick active layers is of crucial importance for the roll-to-roll printing of large-area solar panels. Unfortunately, increasing the active layer thickness usually results in a significant reduction in efficiency. Herein, we fabricated efficient thick-film OSCs with an active layer consisting of one polymer donor and two non-fullerene acceptors. The two acceptors were found to possess enlarged exciton diffusion length in the mixed phase, which is beneficial to exciton generation and dissociation. Additionally, layer by layer approach was employed to optimize the vertical phase separation. Benefiting from the synergetic effects of enlarged exciton diffusion length and graded vertical phase separation, a record high efficiency of 17.31% (certified value of 16.9%) was obtained for the 300 nm-thick OSC, with an unprecedented short-circuit current density of 28.36 mA cm−2, and a high fill factor of 73.0%. Moreover, the device with an active layer thickness of 500 nm also shows a record efficiency of 15.21%. This work provides new insights into the fabrication of high-efficiency OSCs with thick active layers.

scholarly journals Study of Detector-Grade CdMnTe:In Crystals Obtained by a Multi-Step Post-Growth Annealing Method

Crystals ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 387 ◽  
Author(s):  
Pengfei Yu ◽  
Yongren Chen ◽  
Wei Li ◽  
Wenfei Liu ◽  
Bin Liu ◽  
...  
Keyword(s):  
Annealing Temperature ◽  
Crystal Quality ◽  
High Resistivity ◽  
Detector Performance ◽  
Rocking Curve ◽  
X Ray ◽  
Annealing Step ◽  
Subsequent Step ◽  
Te Inclusions ◽  
Annealing Method

A multi-step annealing method was successfully applied to inclusions reduction and resistivity improvement of CdMnTe:In (CMT:In) single crystals with high resistivity, including a Cd atmosphere annealing step followed by a Te atmosphere annealing step. After the Cd atmosphere annealing step, the density of Te inclusions was reduced distinctly, and it could be also decreased in the subsequent step of re-annealing under Te atmosphere. Both the resistivity and IR transmittance decreased notably after Cd atmosphere annealing, whereas they increased tremendously after re-annealing under a Te atmosphere. The reduction of full-width at-half-maximum (FWHM) and the increase of the intensity of the X-ray rocking curve indicated an improvement of the crystal quality. Meanwhile, after Cd atmosphere annealing, the increase of the intensity of the (D0,X) peak and the disappearance of the (A0,X) peak in photoluminescence (PL) measurements suggested further that the crystal quality was improved. The detector performance was enhanced obviously after annealing. The higher the annealing temperature, the better the performance was. The detector fabricated by CMT:In slice (Cd atmosphere annealing at 1073 K for 240 h and Te atmosphere re-annealing at 773 K for 120 h) with 9.43% energy resolution and 1.25 × 10−3 cm2/V μτ value had the best detector performance.

Defects in Silver-Doped Mercuric Iodide Crystals and their Effect on X-Ray and Gamma-Ray Detector Performance

1993 ◽  
Vol 302 ◽  
Author(s):  
R. B. James ◽  
X. J. Bao ◽  
T. E. Schlesinger ◽  
A. Y. Cheng ◽  
V. M. Gerrish
Keyword(s):  
Gamma Ray ◽  
Electrical Contacts ◽  
Source Material ◽  
Broad Emission Band ◽  
Interfacial Region ◽  
Mercuric Iodide ◽  
Detector Performance ◽  
X Ray ◽  
Silver Silver ◽  
Gamma Ray Detector

ABSTRACTThe processing steps associated with purification of source material, crystal growth, and attachment of electrical contacts can introduce defects into mercuric iodide (HgI2) that degrade the performance of detectors. We have employed low-temperature photoluminescence (PL) spectroscopy to study radiative recombination centers in the interfacial region between a thin semitransparent film of silver and mercuric iodide. The Ag film was found to introduce a new broad emission band centered at 5490 Å in the photoluminescence spectrum of HgI2. This PL feature can be used as a signature to identify the existence of Ag as a contaminant in HgI2 crystals and detectors. Experiments were also conducted on mercuric iodide surfaces that had been doped with silver, and the results showed that Ag is a rapid diffuser in bulk HgI2. Detectors with silver electrodes were also fabricated and tested using an americium-241 gamma-ray source. Large increases in the leakage currents were observed for the Ag-doped HgI2 devices, indicated that Ag impurities are electrically active in HgI2. These measurements show that silver is unacceptable as an electrode material for mercuric iodide x-ray and gamma-ray detector applications. In addition, they reveal that caution must be taken during handling of mercuric iodide source material, crystals, and detectors to avoid contact with silver, silver compounds, or with any material that contains silver as a contaminant.

scholarly journals Characteristics of A Hybrid Detector Combined with A Perovskite Active Layer for Indirect X-ray Detection

Sensors ◽  
2020 ◽  
Vol 20 (23) ◽  
pp. 6872
Author(s):  
Hailiang Liu ◽  
Jehoon Lee ◽  
Jungwon Kang
Keyword(s):  
Surface Roughness ◽  
Active Layer ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Lower Surface ◽  
Short Circuit Current Density ◽  
Charge Carriers ◽  
Inorganic Hybrid ◽  
X Ray ◽  
Hybrid Detector

In this study, we investigated the characteristics of an organic-inorganic hybrid indirect-type X-ray detector with a CH3NH3PbI3 (MAPbI3) perovskite active layer. A layer with a thickness of 192 nm annealed at 100 °C showed higher absorption, higher crystallinity, and lower surface roughness than did perovskite layers made under different conditions. In the indirect X-ray detector, a scintillator coupled with the detector to convert X-ray photons to visible photons, and the converted photons were absorbed by the active layer to generate charge carriers. The detector with the optimized MAPbI3 (192 nm thick and 100 °C annealing condition) active layer was coupled with a CsI(Tl) scintillator which consisted of 400 μm thick CsI and 0.5 mm thick Al, and achieved the highest sensitivity, i.e., 2.84 mA/Gy·cm2. In addition, the highest short-circuit current density (JSC), i.e., 18.78 mA/cm2, and the highest mobility, i.e., 2.83 × 10−4 cm2/V·s, were obtained from the same detector without the CsI(Tl) scintillator.

TU-A-116-05: Evaluation of Relative X-Ray Imaging Detector Performance Using the Metric of Relative Object Detectability (ROD)

2013 ◽  
Vol 40 (6Part25) ◽  
pp. 426-427
Author(s):  
V Singh ◽  
A Jain ◽  
S Setlur Nagesh ◽  
D Bednarek ◽  
S Rudin
Keyword(s):  
Detector Performance ◽  
X Ray ◽  
X Ray Imaging ◽  
Imaging Detector

scholarly journals A Study on an Organic Semiconductor-Based Indirect X-ray Detector with Cd-Free QDs for Sensitivity Improvement

Sensors ◽  
2020 ◽  
Vol 20 (22) ◽  
pp. 6562
Author(s):  
Jehoon Lee ◽  
Hailiang Liu ◽  
Jungwon Kang
Keyword(s):  
Quantum Dots ◽  
Indium Phosphide ◽  
Active Layer ◽  
Electron Acceptor ◽  
Organic Semiconductor ◽  
Environmental Problems ◽  
Hazardous Substances ◽  
X Ray ◽  
Sensitivity Improvement ◽  
Optimized Conditions

In this paper, we studied the optimized conditions for adding inorganic quantum dots (QD) to the P3HT:PC70BM organic active layer to increase the sensitivity of the indirect X-ray detector. Commonly used QDs are composed of hazardous substances with environmental problems, so indium phosphide (InP) QDs were selected as the electron acceptor in this experiment. Among the three different sizes of InP QDs (4, 8, and 12 nm in diameter), the detector with 4 nm InP QDs showed the highest sensitivity, of 2.01 mA/Gy·cm2. To further improve the sensitivity, the QDs were fixed to 4 nm in diameter and then the amount of QDs added to the organic active layer was changed from 0 to 5 mg. The highest sensitivity, of 2.26 mA/Gy·cm2, was obtained from the detector with a P3HT:PC70BM:InP QDs (1 mg) active layer. In addition, the highest mobility, of 1.69 × 10−5 cm2/V·s, was obtained from the same detector. Compared to the detector with the pristine P3HT:PC70BM active layer, the detector with a P3HT:PC70BM:InP QDs (1 mg) active layer had sensitivity that was 61.87% higher. The cut-off frequency of the P3HT:PC70BM detector was 21.54 kHz, and that of the P3HT:PC70BM:InP QDs (1 mg) detector was 26.33 kHz, which was improved by 22.24%.

Molecular Ion S2+ and SiFn+ implantations into GaAs

1989 ◽  
Vol 147 ◽  
Author(s):  
W. D. Fan ◽  
W. Y. Wang
Keyword(s):  
Carrier Concentration ◽  
Active Layer ◽  
Concentration Profiles ◽  
Carrier Distribution ◽  
Furnace Annealing ◽  
Molecular Ion ◽  
Pl Spectra ◽  
Active Layers ◽  
Activation Efficiency

AbstractMolecular ion S2+ and SiFn+ implantations into GaAs have been investigated to form very thin active layers. After implantation, the transient annealing (TA) and furnace annealing (FA) were used. The measurements of activation efficiency, mobility, carrier concentration profiles and PL spectra were carried out. The experiments show that after TA, the activation efficiency, mobility and carrier distribution are almost the same between samples implanted with S+ at an energy of 50KeV to a dose of 3×1013cm−2 and S+2 at 100KeV to 1.5×1013cm−2. It shows that the damage of S2-implanted samples can be removed by TA, and a very thin active layer can be formed by the implantation of S2+ at 50KeV. For SiFn-implanted samples, the activation efficiency and mobility. decrease with increase of the implanted ion mass. As+ co-implantation into SiF-implanted samples has been used to improve both activation efficiency and mobility. After comparison with the properties of the SiFt implantation, S2+implantation is more acceptable to form thin active layers.

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