scholarly journals Atomistic Surface Passivation of CH3NH3PbI3 Perovskite Single Crystals for Highly Sensitive Coplanar-Structure X-Ray Detectors

Research ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Yilong Song ◽  
Liqi Li ◽  
Weihui Bi ◽  
Mingwei Hao ◽  
Yifei Kang ◽  
...  
Keyword(s):  
Single Crystals ◽  
Generation X ◽  
Surface Passivation ◽  
Crystal Surface ◽  
High Sensitivity ◽  
Ion Migration ◽  
Metallic Lead ◽  
X Ray ◽  
Highly Sensitive ◽  
Mobile Ions

Organic-inorganic halide perovskites (OIHPs) are recognized as the promising next-generation X-ray detection materials. However, the device performance is largely limited by the ion migration issue of OIHPs. Here, we reported a simple atomistic surface passivation strategy with methylammonium iodide (MAI) to remarkably increase the ion migration activation energy of CH3NH3PbI3 single crystals. The amount of MAI deposited on the crystal surface is finely regulated by a self-assemble process to effectively suppress the metallic lead defects, while not introducing extra mobile ions, which results in significantly improved dark current stability of the coplanar-structure devices under a large electric field of 100 V mm-1. The X-ray detectors hence exhibit a record-high sensitivity above 700,000 μC Gyair‐1 cm‐2 under continuum X-ray irradiation with energy up to 50 keV, which enables an ultralow X-ray detection limit down to 1.5 nGyair s-1. Our findings will allow for the dramatically reduced X-ray exposure of human bodies in medical imaging applications.

scholarly journals Electronic and Crystallographic Examinations of the Homoepitaxially Grown Rubrene Single Crystals

Materials ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1978 ◽  
Author(s):  
Yasuo Nakayama ◽  
Masaki Iwashita ◽  
Mitsuru Kikuchi ◽  
Ryohei Tsuruta ◽  
Koki Yoshida ◽  
...  
Keyword(s):  
Single Crystals ◽  
Valence Band ◽  
Lattice Distortion ◽  
Grazing Incidence ◽  
Valence Band Maximum ◽  
X Ray Diffraction ◽  
X Ray ◽  
Homoepitaxial Growth ◽  
Highly Sensitive ◽  
Doping Ratio

Homoepitaxial growth of organic semiconductor single crystals is a promising methodology toward the establishment of doping technology for organic opto-electronic applications. In this study, both electronic and crystallographic properties of homoepitaxially grown single crystals of rubrene were accurately examined. Undistorted lattice structures of homoepitaxial rubrene were confirmed by high-resolution analyses of grazing-incidence X-ray diffraction (GIXD) using synchrotron radiation. Upon bulk doping of acceptor molecules into the homoepitaxial single crystals of rubrene, highly sensitive photoelectron yield spectroscopy (PYS) measurements unveiled a transition of the electronic states, from induction of hole states at the valence band maximum at an adequate doping ratio (10 ppm), to disturbance of the valence band itself for excessive ratios (≥ 1000 ppm), probably due to the lattice distortion.

scholarly journals Construction of Two Stable Co(II)-Based Hydrogen-Bonded Organic Frameworks as a Luminescent Probe for Recognition of Fe3+ and Cr2O72− in H2O

Molecules ◽  
2021 ◽  
Vol 26 (19) ◽  
pp. 5955
Author(s):  
Qi-Ying Weng ◽  
Ya-Li Zhao ◽  
Jia-Ming Li ◽  
Miao Ouyang
Keyword(s):  
Detection Limit ◽  
Aqueous Media ◽  
Three Dimensional ◽  
Cobalt Atom ◽  
High Sensitivity ◽  
X Ray Diffraction ◽  
Chlorobenzoic Acid ◽  
X Ray ◽  
Highly Sensitive ◽  
Hydrogen Bonded

A pair of cobalt(II)-based hydrogen-bonded organic frameworks (HOFs), [Co(pca)2(bmimb)]n (1) and [Co2(pca)4(bimb)2] (2), where Hpca = p-chlorobenzoic acid, bmimb = 1,3-bis((2-methylimidazol-1-yl)methyl)benzene, and bimb = 1,4-bis(imidazol-1-ylmethyl)benzene were hydrothermally synthesized and characterized through infrared spectroscopy (IR), elemental and thermal analysis (EA), power X-ray diffraction (PXRD), and single-crystal X-ray diffraction (SCXRD) analyses. X-ray diffraction structural analysis revealed that 1 has a one-dimensional (1D) infinite chain network through the deprotonated pca− monodentate chelation and with a μ2-bmimb bridge Co(II) atom, and 2 is a binuclear Co(II) complex construction with a pair of symmetry-related pca− and bimb ligands. For both 1 and 2, each cobalt atom has four coordinated twisted tetrahedral configurations with a N2O2 donor set. Then, 1 and 2 are further extended into three-dimensional (3D) or two-dimensional (2D) hydrogen-bonded organic frameworks through C–H···Cl interactions. Topologically, HOFs 1 and 2 can be simplified as a 4-connected qtz topology with a Schläfli symbol {64·82} and a 4-connected sql topology with a Schläfli symbol {44·62}, respectively. The fluorescent sensing application of 1 was investigated; 1 exhibits high sensitivity recognition for Fe3+ (Ksv: 10970 M−1 and detection limit: 19 μM) and Cr2O72− (Ksv: 12960 M−1 and detection limit: 20 μM). This work provides a feasible detection platform of HOFs for highly sensitive discrimination of Fe3+ and Cr2O72− in aqueous media.

Mixed‐Cation MA x Cs 1− x PbBr 3 Perovskite Single Crystals with Composition Management for High‐Sensitivity X‐Ray Detection

2020 ◽  
Vol 14 (10) ◽  
pp. 2000226 ◽  
Author(s):  
Zhengfang Fan ◽  
Jiang Liu ◽  
Wentao Zuo ◽  
Guoqiang Liu ◽  
Xulin He ◽  
...  
Keyword(s):  
Single Crystals ◽  
High Sensitivity ◽  
X Ray ◽  
Mixed Cation

Monolithic integration of hybrid perovskite single crystals with heterogenous substrate for highly sensitive X-ray imaging

2017 ◽  
Vol 11 (5) ◽  
pp. 315-321 ◽  
Author(s):  
Wei Wei ◽  
Yang Zhang ◽  
Qiang Xu ◽  
Haotong Wei ◽  
Yanjun Fang ◽  
...  
Keyword(s):  
Single Crystals ◽  
Monolithic Integration ◽  
X Ray ◽  
Hybrid Perovskite ◽  
X Ray Imaging ◽  
Highly Sensitive

X-ray emission spectroscopy: highly sensitive techniques for time-resolved probing of cerium reactivity under catalytic conditions

2016 ◽  
Vol 18 (47) ◽  
pp. 32486-32493 ◽  
Author(s):  
R. Kopelent ◽  
J. A. van Bokhoven ◽  
M. Nachtegaal ◽  
J. Szlachetko ◽  
O. V. Safonova
Keyword(s):  
Emission Spectroscopy ◽  
High Sensitivity ◽  
Time Resolved ◽  
X Ray ◽  
Highly Sensitive

High sensitivity of X-ray emission spectroscopy based methods for in situ time-resolved quantification of Ce3+ in ceria-based catalysts and related materials.

Microstructural and Micromorphological Studies on ZnSe Single Crystals Using AFM/FE-SEM/RO-XRD

2007 ◽  
Vol 336-338 ◽  
pp. 633-636 ◽  
Author(s):  
Huan Yong Li ◽  
Wan Qi Jie ◽  
Xiao Qin Wang ◽  
Ke Wei Xu
Keyword(s):  
Single Crystals ◽  
Crystal Surface ◽  
Growth Parameters ◽  
Two Dimensional ◽  
X Ray Diffraction ◽  
Growth Layer ◽  
Dendritic Crystal ◽  
X Ray ◽  
Atomic Force ◽  
Surface Micromorphology

The microstructure and surface micromorphology of ZnSe single crystals grown directly from zinc and selenium have been investigated using rotation orientation x-ray diffraction (RO-XRD), atomic force microscope (AFM) and field emission scanning electron microscope (FE-SEM). The ZnSe samples exhibit only the surface leaning to (111) singular face by the angle of 3.13°, which is the buildup of two-dimensional dendritic crystal layers. Numerous nuclei and cavities distribute unevenly across the crystal surface, governing the formation of growth layer, while the dendritic crystal layers develop rapidly by margining the smaller nuclei. The formation of these microstructure and micromorphology on the surface of ZnSe crystals depends on the surface supersaturation and the growth parameters.

Diffraction Effects from Irradiated Aluminum Single Crystals*

1962 ◽  
Vol 6 ◽  
pp. 164-171
Author(s):  
H. E. Kissinger
Keyword(s):  
Single Crystals ◽  
Crystal Surface ◽  
Irradiation Damage ◽  
X Ray Diffraction ◽  
X Ray ◽  
Integrated Intensity ◽  
Diffraction Effects ◽  
Induced Defects ◽  
Irradiation Induced Defects ◽  
Trapping Sites

AbstractThe effect of substructural perfection on the accumulation of irradiation damage in aluminum was examined. Large single crystals with extensive substructure and crystals essentially free of substructure, all with faces cut parallel to crystal planes, were subjected to neutron irradiation. Subsequent examination by X-ray diffraction revealed pronounced changes in integrated intensity and Debye-Waller temperature factor for the substructure-free crystals; these effects disappeared upon re-etching of the surface. Laue photographs showed that the normal single-crystal pattern was partially obscured by a polycrystalline effect which also disappeared upon etching. Crystals with extensive substructure showed no such effects.This diffraction evidence supports the view that irradiation-induced defects in aluminum migrate to and collect at the crystal surface if no internal trapping sites exist.

scholarly journals Inch-Size 0D-Structured Lead-Free Perovskite Single Crystals for Highly Sensitive Stable X-Ray Imaging

Matter ◽  
2020 ◽  
Vol 3 (1) ◽  
pp. 180-196 ◽  
Author(s):  
Yucheng Liu ◽  
Zhuo Xu ◽  
Zhou Yang ◽  
Yunxia Zhang ◽  
Jian Cui ◽  
...  
Keyword(s):  
Single Crystals ◽  
Lead Free ◽  
X Ray ◽  
X Ray Imaging ◽  
Highly Sensitive

scholarly journals Ligand assisted growth of perovskite single crystals with low defect density

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Ye Liu ◽  
Xiaopeng Zheng ◽  
Yanjun Fang ◽  
Ying Zhou ◽  
Zhenyi Ni ◽  
...  
Keyword(s):  
Single Crystals ◽  
High Performance ◽  
Defect Density ◽  
Solution Process ◽  
Detection Sensitivity ◽  
Crystal Surfaces ◽  
Ion Migration ◽  
X Ray ◽  
Metal Halide Perovskite ◽  
Perovskite Crystal

AbstractA low defect density in metal halide perovskite single crystals is critical to achieve high performance optoelectronic devices. Here we show the reduction of defect density in perovskite single crystals grown by a ligand-assisted solution process with 3‐(decyldimethylammonio)‐propane‐sulfonate inner salt (DPSI) as an additive. DPSI ligands anchoring with lead ions on perovskite crystal surfaces not only suppress nucleation in solution, but also regulate the addition of proper ions to the growing surface, which greatly enhances the crystal quality. The grown CH3NH3PbI3 crystals show better crystallinity and a 23-fold smaller trap density of 7 × 1010 cm−3 than the optimized control crystals. The enhanced material properties result in significantly suppressed ion migration and superior X-ray detection sensitivity of CH3NH3PbI3 detectors of (2.6 ± 0.4) × 106 µC Gy−1air cm−2 for 60 kVp X-ray and the lowest detectable dose rate reaches (5.0 ± 0.7) nGy s−1, which enables reduced radiation dose to patients in medical X-ray diagnostics.

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