pwc-archive/papers-with-abstracts huggingface dataset:
Centimeter-scale single-crystalline perovskite thin film/membrane for high gain and detectivity photosensors/photodetector
Authors: Deng YH
Date: 2020-07-20 00:00:00

Abstract: Modern electronic and photonic devices rely on single-crystalline thin film semiconductors for high performance and reproducibility. The emerging halide perovskites have extraordinary electronic and photonic properties and can be synthesized via low cost solution-based methods. They have been used in a variety of devices with performance approaching or over the devices based on conventional materials. However, their solution based growth method is intrinsically challenge to grow large scale single-crystalline thin film due to the random nucleation and isotropous growth of the crystal. Here, we report the growth of centimeter-scale perovskite single-crystalline thin films by controlling the nucleation density and growth rate of the crystal under a spatially confined growth condition. The hydrophobic treatment on substrates inhibits nucleation and accelerates the growth of single-crystalline thin film, providing enough space for initial nucleus growing up quickly without touching each other. Single-crystalline perovskite thin-film with an aspect ratio of 1000 (1 cm in side length, 10 μm in thickness) has been successfully grown. The low trap density and the high mobility of the as-grown thin film show a high crystallinity. The photodetector based on the perovskite thin film has achieved a gain ~ 10^4, benefitting from the short transit time of the carries due to the high mobility and thin thickness of the active layer. Our work opens up a new route to grow large scale perovskite single-crystalline thin films, providing a platform to develop high- performance devices.

Cite this article: Deng, YH., Yang, ZQ. & Ma, RM. Growth of centimeter-scale perovskite single-crystalline thin film via surface engineering. Nano Convergence 7, 25 (2020). https://doi.org/10.1186/s40580-020-00236-5

DOI: https://doi.org/10.1186/s40580-020-00236-5
Shape-controlled growth of large-scale perovskite single-crystal thin film
Authors: Deng, YH., Yang, ZQ. & Ma, RM
Date: 2020-07-20 00:00:00

Abstract: Modern electronic and photonic devices rely on single-crystalline thin film semiconductors for high performance and reproducibility. The emerging halide perovskites have extraordinary electronic and photonic properties and can be synthesized via low cost solution-based methods. They have been used in a variety of devices with performance approaching or over the devices based on conventional materials. However, their solution based growth method is intrinsically challenge to grow large scale single-crystalline thin film due to the random nucleation and isotropous growth of the crystal. Here, we report the growth of centimeter-scale perovskite single-crystalline thin films by controlling the nucleation density and growth rate of the crystal under a spatially confined growth condition. The hydrophobic treatment on substrates inhibits nucleation and accelerates the growth of single-crystalline thin film, providing enough space for initial nucleus growing up quickly without touching each other. Single-crystalline perovskite thin-film with an aspect ratio of 1000 (1 cm in side length, 10 μm in thickness) has been successfully grown. The low trap density and the high mobility of the as-grown thin film show a high crystallinity. The photodetector based on the perovskite thin film has achieved a gain ~ 10^4, benefitting from the short transit time of the carries due to the high mobility and thin thickness of the active layer. Our work opens up a new route to grow large scale perovskite single-crystalline thin films, providing a platform to develop high- performance devices.

Cite this article: Deng, YH., Yang, ZQ. & Ma, RM. Growth of centimeter-scale perovskite single-crystalline thin film via surface engineering. Nano Convergence 7, 25 (2020). https://doi.org/10.1186/s40580-020-00236-5
Misidentifications in High-Resolution TEM Characterization of Perovskite Materials
Authors: dengyuhao
Date: 2020-12-29 00:00:00
Tasks: Vocal Bursts Intensity Prediction

Abstract: High-resolution TEM (HRTEM) is a powerful tool for structure characterization. However, methylammonium lead iodide (MAPbI3) perovskite is highly sensitive to electron beams and easily decomposes into lead iodide (PbI2). Misidentifications, such as PbI2 being incorrectly labeled as perovskite, are widely present in HRTEM characterization and would negatively affect the development of perovskite research field. Here misidentifications in MAPbI3 perovskite are summarized, classified, and corrected based on low-dose imaging and electron diffraction (ED) simulations. Corresponding crystallographic parameters of intrinsic tetragonal MAPbI3 and the confusable hexagonal PbI2 are presented unambiguously. Finally, the method of proper phase identification and some strategies to control the radiation damage in HRTEM are provided. This warning paves the way to avoid future misinterpretations in HRTEM characterization of perovskite and other electron beam-sensitive materials.

Keywords: MAPbI3 perovskite; transmission electron microscopy (TEM); electron diffraction (ED); phase identification; electron beam-sensitive

Cite: Deng, Y.-H. Common Phase and Structure Misidentifications in High-Resolution TEM Characterization of Perovskite Materials. Condens. Matter 2021, 6, 1.

DOI: https://doi.org/10.3390/condmat6010001
Transmission Electron Microscopy Specimen Preparation of Nnanomaterials Using Sublimable Carrier
Authors: Deng, YH.
Date: 2020-09-29 00:00:00

Abstract: Sample preparation is significantly important to the high-resolution transmission electron microscopy (HRTEM) characterization of nanomaterials. However, many general organic solvents can dissolve the necessary organic polymer support layer in TEM grid, which causes it difficult to obtain high-quality samples of oil-soluble nanomaterials. In this study, a new sample preparation method for oil-soluble nanomaterials has been developed by using the sublimable material as a transition layer. Experiments also show that there is no damage to TEM grids and high-quality HRTEM images can be obtained via this method. This approach paves the way to applicable HRTEM sample preparation of oil-soluble nanomaterials.

Cite this article: Deng, YH. Sublimable materials facilitate the TEM sample preparation of oil-soluble nanomaterials. Appl. Microsc. 50, 21 (2020). https://doi.org/10.1186/s42649-020-00042-7

DOI: https://doi.org/10.1186/s42649-020-00042-7
Transmission electron microscopy sample preparation protocols for oil-soluble nanomaterials
Authors: dengyuhao
Date: 2020-09-04 00:00:00

Abstract
Sample preparation is significantly important to the high-resolution transmission electron microscopy (HRTEM) characterization of nanomaterials. However, many general organic solvents can dissolve the necessary organic polymer support layer in TEM grid, which causes it difficult to obtain high-quality samples of oil-soluble nanomaterials. In this study, a new sample preparation method for oil-soluble nanomaterials has been developed by using the sublimable material as a transition layer. Experiments also show that there is no damage to TEM grids and high-quality HRTEM images can be obtained via this method. This approach paves the way to applicable HRTEM sample preparation of oil-soluble nanomaterials.

Cite this article:
Deng, YH. Sublimable materials facilitate the TEM sample preparation of oil-soluble nanomaterials. Appl. Microsc. 50, 21 (2020). https://doi.org/10.1186/s42649-020-00042-7
Preparing samples for the electron microscope using sublimable naphthalene
Authors: Appl. Microsc.
Date: 2020-09-21 00:00:00

Abstract: Sample preparation is significantly important to the high-resolution transmission electron microscopy (HRTEM) characterization of nanomaterials. However, many general organic solvents can dissolve the necessary organic polymer support layer in TEM grid, which causes it difficult to obtain high-quality samples of oil-soluble nanomaterials. In this study, a new sample preparation method for oil-soluble nanomaterials has been developed by using the sublimable material as a transition layer. Experiments also show that there is no damage to TEM grids and high-quality HRTEM images can be obtained via this method. This approach paves the way to applicable HRTEM sample preparation of oil-soluble nanomaterials.

Keywords: Transmission electron microscopy, Sample preparation, Oil-soluble nanomaterial, Sublimable material, naphthalene

Cite this article: Deng, YH. Sublimable materials facilitate the TEM sample preparation of oil-soluble nanomaterials. Appl. Microsc. 50, 21 (2020). https://doi.org/10.1186/s42649-020-00042-7
Specimen Preparation for Transmission Electron Microscopy using sublimable naphthalene
Authors: Deng, y
Date: 2020-09-04 00:00:00

Abstract: Sample preparation is significantly important to the high-resolution transmission electron microscopy (HRTEM) characterization of nanomaterials. However, many general organic solvents can dissolve the necessary organic polymer support layer in TEM grid, which causes it difficult to obtain high-quality samples of oil-soluble nanomaterials. In this study, a new sample preparation method for oil-soluble nanomaterials has been developed by using the sublimable material as a transition layer. Experiments also show that there is no damage to TEM grids and high-quality HRTEM images can be obtained via this method. This approach paves the way to applicable HRTEM sample preparation of oil-soluble nanomaterials.
Keywords: Transmission electron microscopy, Sample preparation, Oil-soluble nanomaterial, Sublimable material.
Conclusions: This new method avoids the destruction of organic polymer layer in TEM grid by organic solvent and can obtain high-quality TEM samples in the characterization of oil-soluble nanomaterials. Our method not only can be used for the preparation of nanocrystals sample, but also can be applied to oil-soluble nanoclusters, nanosheets, nanowires and other materials. In addition to oil-soluble nanomaterials, other nanomaterials in corrosive solutions such as strong acids and bases can also be suitable for this method. This work enriches and improves the sample preparation technique in the field of TEM.

Cite this article: Deng, YH. Sublimable materials facilitate the TEM sample preparation of oil-soluble nanomaterials. Appl. Microsc. 50, 21 (2020). https://doi.org/10.1186/s42649-020-00042-7

DOI: https://doi.org/10.1186/s42649-020-00042-7
Sublimable Materials Facilitate the Sample Preparation for Transmission Electron Microscopy
Authors: yuhao deng
Date: 2020-09-20 00:00:00

Abstract: Sample preparation is significantly important to the high-resolution transmission electron microscopy (HRTEM) characterization of nanomaterials. However, many general organic solvents can dissolve the necessary organic polymer support layer in TEM grid, which causes it difficult to obtain high-quality samples of oil-soluble nanomaterials. In this study, a new sample preparation method for oil-soluble nanomaterials has been developed by using the sublimable material as a transition layer. Experiments also show that there is no damage to TEM grids and high-quality HRTEM images can be obtained via this method. This approach paves the way to applicable HRTEM sample preparation of oil-soluble nanomaterials.

Conclusions: This new method avoids the destruction of organic polymer layer in TEM grid by organic solvent and can obtain high-quality TEM samples in the characterization of oil-soluble nanomaterials. Our method not only can be used for the preparation of nanocrystals sample, but also can be applied to oil-soluble nanoclusters, nanosheets, nanowires and other materials. In addition to oil-soluble nanomaterials, other nanomaterials in corrosive solutions such as strong acids and bases can also be suitable for this method. This work enriches and improves the sample preparation technique in the field of TEM.

Cite this article: Deng, YH. Sublimable materials facilitate the TEM sample preparation of oil-soluble nanomaterials. Appl. Microsc. 50, 21 (2020). https://doi.org/10.1186/s42649-020-00042-7
New Sample Preparation Method for Transmission Electron Microscopy (TEM)
Authors: Deng
Date: 2020-07-04 00:00:00

Cite this article: Deng, YH. Sublimable materials facilitate the TEM sample preparation of oil-soluble nanomaterials. Appl. Microsc. 50, 21 (2020). https://doi.org/10.1186/s42649-020-00042-7

Abstract: Sample preparation is significantly important to the high-resolution transmission electron microscopy (HRTEM) characterization of nanomaterials. However, many general organic solvents can dissolve the necessary organic polymer support layer in TEM grid, which causes it difficult to obtain high-quality samples of oil-soluble nanomaterials. In this study, a new sample preparation method for oil-soluble nanomaterials has been developed by using the sublimable material as a transition layer. Experiments also show that there is no damage to TEM grids and high-quality HRTEM images can be obtained via this method. This approach paves the way to applicable HRTEM sample preparation of oil-soluble nanomaterials.

Results and discussion: Here, a new method for nanomaterial sample preparation was designed by introduce sublimable naphthalene as the transition layer. First, naphthalene was deposited on the substrate and nanomaterials were sprayed onto naphthalene layer. Next, the side of the naphthalene layer with the nanomaterial was transferred to covered on the TEM grid, and then place the sample in a vacuum to sublimate naphthalene. The process is shown in Fig. 2. Based on this method, we obtained a continuous large-scale highly-dispersed oil-soluble PbS nanocrystal sample and captured high-quality TEM (Fig. 3a), High-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) (Fig. 3b) and HRTEM (Fig. 3c) images. It proves that images with low background contrast, accurate material morphology, and clear lattice fringes can be obtained via this new sample preparation method.
Transmission electron microscopy specimen preparation technique using sublimable materials: Application to oil-soluble nanomaterials
Authors: Applied Microscopy
Date: 2020-07-29 00:00:00

Abstract: Sample preparation is significantly important to the high-resolution transmission electron microscopy (HRTEM) characterization of nanomaterials. However, many general organic solvents can dissolve the necessary organic polymer support layer in TEM grid, which causes it difficult to obtain high-quality samples of oil-soluble nanomaterials. In this study, a new sample preparation method for oil-soluble nanomaterials has been developed by using the sublimable material as a transition layer. Experiments also show that there is no damage to TEM grids and high-quality HRTEM images can be obtained via this method. This approach paves the way to applicable HRTEM sample preparation of oil-soluble nanomaterials.

Keywords: Transmission electron microscopy, Sample preparation, Oil-soluble nanomaterial, Sublimable material.

Cite this article: Deng, YH. Sublimable materials facilitate the TEM sample preparation of oil-soluble nanomaterials. Appl. Microsc. 50, 21 (2020). https://doi.org/10.1186/s42649-020-00042-7

DOI: https://doi.org/10.1186/s42649-020-00042-7
How to Prepare a Transmission Electron Microscopy (TEM) Sample of Nanomaterials
Authors: TEM Sample
Date: 2020-09-21 00:00:00

Cite this article: Deng, YH. Sublimable materials facilitate the TEM sample preparation of oil-soluble nanomaterials. Appl. Microsc. 50, 21 (2020). https://doi.org/10.1186/s42649-020-00042-7

Abstract: Sample preparation is significantly important to the high-resolution transmission electron microscopy (HRTEM) characterization of nanomaterials. However, many general organic solvents can dissolve the necessary organic polymer support layer in TEM grid, which causes it difficult to obtain high-quality samples of oil-soluble nanomaterials. In this study, a new sample preparation method for oil-soluble nanomaterials has been developed by using the sublimable material as a transition layer. Experiments also show that there is no damage to TEM grids and high-quality HRTEM images can be obtained via this method. This approach paves the way to applicable HRTEM sample preparation of oil-soluble nanomaterials.

Introduction: Sample preparation is significantly important to the transmission electron microscopy (TEM) characterization for the accurate morphology and crystal structure of nanomaterials (Ayache et al. 2010; Cha et al. 2016; Kim et al. 2014; Park et al. 2016). In order to obtain high-quality high-resolution TEM (HRTEM) images, nanomaterials are often dispersed on the TEM grid, wherein an organic polymer film acts as a reinforced support layer between the ultra-thin carbon film (~ 4 nm) and copper mesh (Fig. 1a) (Regan et al. 2010; Warner et al. 2010; Kennedy et al. 1998). The organic polymer film is necessary for the HRTEM characterization of ultra-small nanomaterials, especially nanocrystalline materials. However, the organic polymer support layer can be dissolved by many general organic reagents (chloroform, methylbenzene, etc), which limits the sample preparation of oil-soluble nanomaterials (Kearns et al. 2006).
Strategies for transmission electron microscopy specimen preparation of nanomaterials using sublimable carrier
Authors: microscopy
Date: 2020-09-28 00:00:00

Cite this article: Deng, YH. Sublimable materials facilitate the TEM sample preparation of oil-soluble nanomaterials. Appl. Microsc. 50, 21 (2020). https://doi.org/10.1186/s42649-020-00042-7

Abstract: Sample preparation is significantly important to the high-resolution transmission electron microscopy (HRTEM) characterization of nanomaterials. However, many general organic solvents can dissolve the necessary organic polymer support layer in TEM grid, which causes it difficult to obtain high-quality samples of oil-soluble nanomaterials. In this study, a new sample preparation method for oil-soluble nanomaterials has been developed by using the sublimable material as a transition layer. Experiments also show that there is no damage to TEM grids and high-quality HRTEM images can be obtained via this method. This approach paves the way to applicable HRTEM sample preparation of oil-soluble nanomaterials.

Here, a new method for nanomaterial sample preparation was designed by introduce sublimable naphthalene as the transition layer. First, naphthalene was deposited on the substrate and nanomaterials were sprayed onto naphthalene layer. Next, the side of the naphthalene layer with the nanomaterial was transferred to covered on the TEM grid, and then place the sample in a vacuum to sublimate naphthalene. The process is shown in Fig. 2. Based on this method, we obtained a continuous large-scale highly-dispersed oil-soluble PbS nanocrystal sample and captured high-quality TEM (Fig. 3a), High-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) (Fig. 3b) and HRTEM (Fig. 3c) images. It proves that images with low background contrast, accurate material morphology, and clear lattice fringes can be obtained via this new sample preparation method.
The Highest Performance of Single-Crystalline Perovskite Thin-Film Photodetectors
Date: 2017-08-01 00:00:00

Abstract: The best performing modern optoelectronic devices rely on single‐crystalline thin‐film (SC‐TF) semiconductors grown epitaxially. The emerging halide perovskites, which can be synthesized via low‐cost solution‐based methods, have achieved substantial success in various optoelectronic devices including solar cells, lasers, light‐emitting diodes, and photodetectors. However, to date, the performance of these perovskite devices based on polycrystalline thin‐film active layers lags behind the epitaxially grown semiconductor devices. Here, a photodetector based on SC‐TF perovskite active layer is reported with a record performance of a 50 million gain, 70 GHz gain‐bandwidth product, and a 100‐photon level detection limit at 180 Hz modulation bandwidth, which as far as we know are the highest values among all the reported perovskite photodetectors. The superior performance of the device originates from replacing polycrystalline thin film by a thickness‐optimized SC‐TF with much higher mobility and longer recombination time. The results indicate that high‐performance perovskite devices based on SC‐TF may become competitive in modern optoelectronics.

Keywords: gain, halide perovskite, photodetectors, single‐crystalline thin films.
Cite: Yang Z, Deng Y, Zhang X, et al. High‐Performance Single‐Crystalline Perovskite Thin‐Film Photodetector[J]. Advanced Materials, 2018, 30(8): 1704333. DOI: https://doi.org/10.1002/adma.201704333
Synthesis of centimeter-size free-standing perovskite single-crystal thin film via surface engineering for optoelectronic devices
Authors: Deng, Y-H
Date: 2020-07-18 00:00:00

Abstract: Modern electronic and photonic devices rely on single-crystalline thin film semiconductors for high performance and reproducibility. The emerging halide perovskites have extraordinary electronic and photonic properties and can be synthesized via low cost solution-based methods. They have been used in a variety of devices with performance approaching or over the devices based on conventional materials. However, their solution based growth method is intrinsically challenge to grow large scale single-crystalline thin film due to the random nucleation and isotropous growth of the crystal. Here, we report the growth of centimeter-scale perovskite single-crystalline thin films by controlling the nucleation density and growth rate of the crystal under a spatially confined growth condition. The hydrophobic treatment on substrates inhibits nucleation and accelerates the growth of single-crystalline thin film, providing enough space for initial nucleus growing up quickly without touching each other. Single-crystalline perovskite thin-film with an aspect ratio of 1000 (1 cm in side length, 10 μm in thickness) has been successfully grown. The low trap density and the high mobility of the as-grown thin film show a high crystallinity. The photodetector based on the perovskite thin film has achieved a gain ~ 10^4, benefitting from the short transit time of the carries due to the high mobility and thin thickness of the active layer. Our work opens up a new route to grow large scale perovskite single-crystalline thin films, providing a platform to develop high- performance devices.

Keywords: Perovskite, Single-crystalline thin film, Hydrophobic, Photodetector, Gain.

Cite this article: Deng, YH., Yang, ZQ. & Ma, RM. Growth of centimeter-scale perovskite single-crystalline thin film via surface engineering. Nano Convergence 7, 25 (2020). https://doi.org/10.1186/s40580-020-00236-5