Black phosphorus-based smart electrorheological fluid with tailored phase transition and exfoliation

Yun Ki Kim,Yeri Lee,Keun-Young Shin 한국공업화학회 2020 Journal of Industrial and Engineering Chemistry Vol.90 No.-

The effect of phase transition and exfoliation time on electro-responsive behavior of black phosphorus isidentified by introducing black phosphorus and phosphorene to electrorheologicalfluid. Blackphosphorus is successfully fabricated by mechanical milling for phase transition from red phosphorus,and phosphorene is fabricated by ultrasonication of the prepared black phosphorus. The morphology,degree of phase transition, and electrical conductivity of black phosphorus and phosphorene areprecisely controlled by modifying the duration of both milling and delamination. It can be corroboratedfrom a comprehensive study that the electrical conductivity as well as morphology affect the electroresponsivebehaviors of black phosphorus and phosphorene. To the best of our knowledge, this is thefirstreport on the meticulous control of phase transition and the potential of both black phosphorus andphosphorene as candidate materials for lectrorheologicalfluids. This study may provide understanding ofthe electro-responsive characteristics of black phosphorus and phosphorene, broadening the perspectiveof electro-responsive smartfluids.

Formation of Stable Phosphorus–Carbon Bond for Enhanced Performance in Black Phosphorus Nanoparticle–Graphite Composite Battery Anodes

Sun, Jie,Zheng, Guangyuan,Lee, Hyun-Wook,Liu, Nian,Wang, Haotian,Yao, Hongbin,Yang, Wensheng,Cui, Yi American Chemical Society 2014 NANO LETTERS Vol.14 No.8

<P>High specific capacity battery electrode materials have attracted great research attention. Phosphorus as a low-cost abundant material has a high theoretical specific capacity of 2596 mAh/g with most of its capacity at the discharge potential range of 0.4–1.2 V, suitable as anodes. Although numerous research progress have shown other high capacity anodes such as Si, Ge, Sn, and SnO<SUB>2</SUB>, there are only a few studies on phosphorus anodes despite its high theoretical capacity. Successful applications of phosphorus anodes have been impeded by rapid capacity fading, mainly caused by large volume change (around 300%) upon lithiation and thus loss of electrical contact. Using the conducting allotrope of phosphorus, “black phosphorus” as starting materials, here we fabricated composites of black phosphorus nanoparticle-graphite by mechanochemical reaction in a high energy mechanical milling process. This process produces phosphorus–carbon bonds, which are stable during lithium insertion/extraction, maintaining excellent electrical connection between phosphorus and carbon. We demonstrated high initial discharge capacity of 2786 mAh·g<SUP>–1</SUP> at 0.2 C and an excellent cycle life of 100 cycles with 80% capacity retention. High specific discharge capacities are maintained at fast C rates (2270, 1750, 1500, and 1240 mAh·g<SUP>–1</SUP> at C/5, 1, 2, and 4.5 C, respectively).</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/nalefd/2014/nalefd.2014.14.issue-8/nl501617j/production/images/medium/nl-2014-01617j_0006.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/nl501617j'>ACS Electronic Supporting Info</A></P>

Electronic band structure of surface-doped black phosphorus

Kim, Jimin,Huh, Minjae,Jung, Sung Won,Ryu, Sae Hee,Sohn, Yeongsup,Kim, Keun Su Elsevier 2017 Journal of electron spectroscopy and related pheno Vol.219 No.-

<P><B>Abstract</B></P> <P>We present an overview on the electronic band structure of surface-doped black phosphorus. Angle-resolved photoemission spectroscopy data show that the <I>in situ</I> deposition of potassium atoms on the surface of single-crystalline black phosphorus modulates the band gap in the wide range of 0.0–0.6eV. At zero band gap, the surface layers of black phosphorus become a Dirac semimetal whose band dispersion is highly anisotropic, linear in armchair and quadratic in zigzag directions. In light of theoretical band calculations, we elucidate the mechanism of these band modifications as the giant Stark effect due to strong vertical electric fields induced by potassium atoms.</P> <P><B>Highlights</B></P> <P> <UL> <LI> We provide an experimental study on the band structure of surface-doped black phosphorus. </LI> <LI> The band gap of black phosphorus is widely modulated by the giant Stark effect. </LI> <LI> Black phosphorus with zero bandgap has linear-quadratic band dispersions. </LI> </UL> </P>

Long-term stability study of graphene-passivated black phosphorus under air exposure

Jiho Kim,Seung Kwan Baek,Keun-Soo Kim,Young Jun Chang,E.J. Choi 한국물리학회 2016 Current Applied Physics Vol.16 No.2

We use the graphene as a passivation layer to protect the black phosphorus from chemical reaction with air. Flakes of the black phosphorus crystal are covered by N ¼ 1, 2, and 3 layers of CVD graphene and the Raman phonon modes are measured after the samples are exposed to air. For the double and triple layer passivation (N ¼ 2,3) the Raman phonon peaks are maintained as long as ~100 h (4 days) before the phonon intensity is reduced to 90% of the initial strength, I/I0 ¼ 0.9, demonstrating that the black phosphorus is strongly protected in contrast to the rapid degradation of the bare and single-layer covered black phosphorus. The long term stability achieved by multi-layer graphene passivation makes it possible to perform various electronic and optical experiments aimed for device application of this direct-gap van der Waals semiconductor with high electronic and thermal mobility under ambient environment.

Controlled p-doping of black phosphorus by integration of MoS₂ nanoparticles

Jeon, Sumin,Kim, Minwoo,Jia, Jingyuan,Park, Jin-Hong,Lee, Sungjoo,Song, Young Jae Elsevier 2018 APPLIED SURFACE SCIENCE - Vol.440 No.-

<P><B>Abstract</B></P> <P>Black phosphorus (BP), a new family of two dimensional (2D) layered materials, is an attractive material for future electronic, photonic and chemical sensing devices, thanks to its high carrier density and a direct bandgap of 0.3–2.0 eV, depending on the number of layers. Controllability over the properties of BP by electrical or chemical modulations is one of the critical requirements for future various device applications. Herein, we report a new doping method of BP by integration of density-controlled monolayer MoS<SUB>2</SUB> nanoparticles (NPs). MoS<SUB>2</SUB> NPs with different density were synthesized by chemical vapor deposition (CVD) and transferred onto a few-layer BP channel, which induced a p-doping effect. Scanning electron microscopy (SEM) confirmed the size and distribution of MoS<SUB>2</SUB> NPs with different density. Raman and X-ray photoelectron spectroscopy (XPS) were measured to confirm the oxidation on the edge of MoS<SUB>2</SUB> NPs and a doping effect of MoS<SUB>2</SUB> NPs on a BP channel. The doping mechanism was explained by a charge transfer by work function differences between BP and MoS<SUB>2</SUB> NPs, which was confirmed by Kelvin probe force microscopy (KPFM) and electrical measurements. The hole concentration of BP was controlled with different densities of MoS<SUB>2</SUB> NPs in a range of 10<SUP>12</SUP>–10<SUP>13</SUP> cm<SUP>−2</SUP>.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A new doping method of black phosphorous (black-P) with MoS<SUB>2</SUB> nanoparticles (NPs). </LI> <LI> <I>In situ</I> control of the size and distribution of MoS<SUB>2</SUB> NPs in the CVD furnace. </LI> <LI> The hole concentration of black-P can be controlled in a range of 10<SUP>12</SUP>–10<SUP>13</SUP> cm<SUP>−2</SUP>. </LI> <LI> Black-P was doped with a charge transfer by the work function difference from MoS<SUB>2</SUB> NPs. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

New Method to Determine the Schottky Barrier in Few-Layer Black Phosphorus Metal Contacts

Lee, Su Yeong,Yun, Won Seok,Lee, J. D. American Chemical Society 2017 ACS APPLIED MATERIALS & INTERFACES Vol.9 No.8

<P>Schottky barrier height and carrier polarity are seminal concepts for a practical device application of the interface between semiconductor and metal electrode. Investigation of those concepts is usually made by a conventional method such as the Schottky-Mott rule, incorporating the metal work function and semiconductor electron affinity, or the Fermi level pinning effect, resulting from the metal-induced gap states. Both manners are, however, basically applied to the bulk semiconductor metal contacts. To explore few-layer black phosphorus metal contacts far from the realm of bulk, we propose a new method to determine the Schottky barrier by scrutinizing the layer-by-layer phosphorus electronic structure from the first-principles calculation combined with the state-of-the-art band unfolding technique. In this study, using the new method, we calculate the Schottky barrier height and determine the contact polarity of Ti, Sc, and Al metal contacts to few-layer (mono-, bi-, tri-, and quadlayer) black phosphorus. This gives a significant physical insight toward the. utmost layer-by-layer manipulation of electronic properties of few-layer semiconductor metal contacts.</P>

Thermal annealing of black phosphorus for etching and protection

Yang, Sena,Kim, Ansoon,Park, Jaesung,Kwon, Hyuksang,Lanh, Phung Thi,Hong, Songwoung,Kim, Kyung Joong,Kim, Jeong Won Elsevier 2018 APPLIED SURFACE SCIENCE - Vol.457 No.-

<P><B>Abstract</B></P> <P>Among 2D materials, black phosphorus (BP) with high carrier mobility and a sizable direct bandgap has recently attracted considerable attention for next generation materials. However, one of critical challenges for the applications of BP to electronic or optical devices is its air stability, because it degrades rapidly upon exposure to ambient conditions. Herein, we introduce a simple method to fabricate a stable and thin BP. Upon thermal annealing above 200 °C in air, the stable protection layer of BP oxide is produced at the top of BP surface. Simultaneously, the thermal oxidation of bare BP etches the intrinsic BP layer, resulting in the decrease of BP thickness. By the thermal annealing, the field-effect transistor (FET) shows enhanced device performance of hole mobility by 10 times and on/off ratio by 50 times, compared to bare BP-based FET. The stable performance under ambient condition even without additional passivation is due to BP material stability and removal of surface scattering centres upon thermal annealing process.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A very simple method of thermal annealing to produce stable and thin black phosphorus. </LI> <LI> Upon thermal annealing, a P<SUB>2</SUB>O<SUB>5</SUB>-like protective layer is formed on top of BP flake and eliminates carrier scattering centers. </LI> <LI> The surface protection leads to improve BP-based field-effect transistor (FET) performance. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Improved electrochemical performance through spontaneous reduction of graphene oxide and production of 3D Black phosphorus/Reduced graphene oxide through the addition of black phosphorus

강태훈,백상하,박호석 한국공업화학회 2021 한국공업화학회 연구논문 초록집 Vol.2021 No.0

Two-Dimensionally Layered p-Black Phosphorus/n-MoS₂/p-Black Phosphorus Heterojunctions

Lee, Geonyeop,Pearton, Stephen J.,Ren, Fan,Kim, Jihyun American Chemical Society 2018 ACS APPLIED MATERIALS & INTERFACES Vol.10 No.12

<P>Layered heterojunctions are widely applied as fundamental building blocks for semiconductor devices. For the construction of nanoelectronic and nanophotonic devices, the implementation of two-dimensional materials (2DMs) is essential. However, studies of junction devices composed of 2DMs are still largely focused on single p-n junction devices. In this study, we demonstrate a novel pnp double heterojunction fabricated by the vertical stacking of 2DMs (black phosphorus (BP) and MoS<SUB>2</SUB>) using dry-transfer techniques and the formation of high-quality p-n heterojunctions between the BP and MoS<SUB>2</SUB> in the vertically stacked BP/MoS<SUB>2</SUB>/BP structure. The pnp double heterojunctions allowed us to modulate the output currents by controlling the input current. These results can be applied for the fabrication of advanced heterojunction devices composed of 2DMs for nano(opto)electronics.</P> [FIG OMISSION]</BR>

Ternary nanofiber matrices composed of PCL/black phosphorus/collagen to enhance osteodifferentiation

Lee, Yu Bin,Song, Su-Jin,Shin, Yong Cheol,Jung, Yu Jin,Kim, Bongju,Kang, Moon Sung,Kwon, Il Keun,Hyon, Suong-Hyu,Lee, Hyun Uk,Jung, Seo-Hyun,Lim, Dohyung,Han, Dong-Wook Elsevier 2019 Journal of industrial and engineering chemistry Vol.80 No.-

<P><B>Abstract</B></P> <P>Recently, considerable research has been made on the development of bone tissue engineering (BTE) scaffolds to support cellular behaviors. Here, black phosphorus-incorporated poly(ε-caprolactone) and collagen (PCL/BP/Col) nanofiber matrices were designed and their potential as BTE scaffolds were explored. The PCL/BP/Col nanofiber matrices were fabricated successfully by electrospinning, showing that they were suitable for supporting cell growth. The PCL/BP/Col nanofiber matrices could promote not only initial attachment and proliferation, but also osteodifferentiation of preosteoblasts. In conclusion, PCL/BP/Col nanofiber matrices possess excellent biocompatibility and improve osteogenic differentiation. Therefore, the PCL/BP/Col nanofiber matrices can be a promising candidate as a scaffold for BTE.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Black phosphorus (BP)-incorporated PCL and collagen nanofiber matrix is designed. </LI> <LI> PCL/BP/Col nanofiber matrix favorably supports cell growth. </LI> <LI> Biocompatibility and biofunctionality of PCL/BP/Col matrix is demonstrated. </LI> <LI> PCL/BP/Col matrix can stimulate spontaneous osteodifferentiation. </LI> <LI> PCL/BP/Col matrix can be employed as a bone tissue engineering scaffold. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>