The Experts below are selected from a list of 1167 Experts worldwide ranked by ideXlab platform
Gyu-chul Yi - One of the best experts on this subject based on the ideXlab platform.
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Free-standing and ultrathin inorganic light-emitting diode array
NPG Asia Materials, 2019Co-Authors: Youngbin Tchoe, Keundong Lee, Janghyun Jo, Kyungmin Chung, Miyoung Kim, Kunook Chung, Jerome K. Hyun, Gyu-chul YiAbstract:Light-emitting diodes: Free-standing, ultrathin, and high-resolution light sourcesA free-standing, ultrathin and flexible film of micrometer-scale semiconductor light sources has been created by scientists in South Korea. Light-emitting diodes are rapidly replacing less efficient alternatives in both lighting and displays but the traditional inorganic semiconductor materials they are made of are rigid, which means it is difficult to adapt them to applications requiring curved or flexible devices. Gyu-Chul Yi from the Seoul National University and co-workers developed uniquely addressable gallium nitride microdisk light-emitting diode arrays embedded in free-standing and ultrathin polyimide layers. Gallium nitride microdisk arrays they grew on graphene Microdots were easily released from the substrate due to the weak bond between the graphene and the underlying substrate. This approach could be used to create ultraflexible and high-resolution light-sources for wearable, medical or implantable device applications.AbstractWe report on the fabrication and characteristics of an individually addressable gallium nitride (GaN) microdisk light-emitting diode (LED) array in free-standing and ultrathin form. A high-quality GaN microdisk array with n -GaN, InGaN/GaN quantum wells and p -GaN layers was epitaxially grown on graphene Microdots patterned on SiO_2/Si substrates. Due to the weak attachment of the graphene Microdots to the growth substrate, a microdisk array coated with a polyimide layer was easily separated from the substrate using mechanical or chemical methods to form an ultrathin free-standing film. Individually addressable microdisk LEDs were created by forming thin metal contacts on the p -GaN and n -GaN surfaces in a crossbar configuration. Each microdisk LED that comprised an ultrahigh resolution array of 2500 pixels per inch was found to be uniquely addressable. The devices in free-standing form exhibited stable electrical and optoelectronic characteristics under extreme bending conditions and continuous operation mode despite the absence of a heat dissipating substrate. These results present promising approaches for the fabrication of high-quality inorganic semiconductor devices for ultrahigh resolution and high-performance flexible applications.We report on the fabrication and characteristics of an individually addressable GaN microdisk LED array in free-standing and ultrathin form. GaN microdisk array was grown on graphene Microdots, and the microstructures coated with a polyimide layer were easily separated from the substrate to form an ultrathin free-standing film. Crossbar configuration of metal leads enabled each microdisk LED in an array to be uniquely addressable. The devices in free-standing form exhibited stable electrical and optoelectronic characteristics under extreme bending conditions and continuous operation mode despite the absence of a heat dissipating substrate.
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Free-standing and ultrathin inorganic light-emitting diode array
NPG Asia Materials, 2019Co-Authors: Youngbin Tchoe, Janghyun Jo, Kyungmin Chung, Kunook Chung, Jerome K. Hyun, Gyu-chul YiAbstract:A free-standing, ultrathin and flexible film of micrometer-scale semiconductor light sources has been created by scientists in South Korea. Light-emitting diodes are rapidly replacing less efficient alternatives in both lighting and displays but the traditional inorganic semiconductor materials they are made of are rigid, which means it is difficult to adapt them to applications requiring curved or flexible devices. Gyu-Chul Yi from the Seoul National University and co-workers developed uniquely addressable gallium nitride microdisk light-emitting diode arrays embedded in free-standing and ultrathin polyimide layers. Gallium nitride microdisk arrays they grew on graphene Microdots were easily released from the substrate due to the weak bond between the graphene and the underlying substrate. This approach could be used to create ultraflexible and high-resolution light-sources for wearable, medical or implantable device applications. We report on the fabrication and characteristics of an individually addressable GaN microdisk LED array in free-standing and ultrathin form. GaN microdisk array was grown on graphene Microdots, and the microstructures coated with a polyimide layer were easily separated from the substrate to form an ultrathin free-standing film. Crossbar configuration of metal leads enabled each microdisk LED in an array to be uniquely addressable. The devices in free-standing form exhibited stable electrical and optoelectronic characteristics under extreme bending conditions and continuous operation mode despite the absence of a heat dissipating substrate. We report on the fabrication and characteristics of an individually addressable gallium nitride (GaN) microdisk light-emitting diode (LED) array in free-standing and ultrathin form. A high-quality GaN microdisk array with n -GaN, InGaN/GaN quantum wells and p -GaN layers was epitaxially grown on graphene Microdots patterned on SiO_2/Si substrates. Due to the weak attachment of the graphene Microdots to the growth substrate, a microdisk array coated with a polyimide layer was easily separated from the substrate using mechanical or chemical methods to form an ultrathin free-standing film. Individually addressable microdisk LEDs were created by forming thin metal contacts on the p -GaN and n -GaN surfaces in a crossbar configuration. Each microdisk LED that comprised an ultrahigh resolution array of 2500 pixels per inch was found to be uniquely addressable. The devices in free-standing form exhibited stable electrical and optoelectronic characteristics under extreme bending conditions and continuous operation mode despite the absence of a heat dissipating substrate. These results present promising approaches for the fabrication of high-quality inorganic semiconductor devices for ultrahigh resolution and high-performance flexible applications.
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Flexible GaN Light-Emitting Diodes Using GaN Microdisks Epitaxial Laterally Overgrown on Graphene Dots.
Advanced Materials, 2016Co-Authors: Kunook Chung, Jerome K. Hyun, Hongseok Oh, Youngbin Tchoe, Hyeonjun Baek, Gyu-chul YiAbstract:: The epitaxial lateral overgrowth (ELOG) of GaN microdisks on graphene Microdots and the fabrication of flexible light-emitting diodes (LEDs) using these microdisks is reported. An ELOG technique with only patterned graphene Microdots is used, without any growth mask. The discrete micro-LED arrays are transferred onto Cu foil by a simple lift-off technique, which works reliably under various bending conditions.
Tetsuo Saji - One of the best experts on this subject based on the ideXlab platform.
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microcontact printing of pigment polymer composite Microdots and electrodeposition of ni walls to fabricate hard and glossy colored films
Surface & Coatings Technology, 2013Co-Authors: Hitoshi Ogihara, Hiro Kibayashi, Tetsuo SajiAbstract:Abstract Pigment/polymer composite Microdots surrounded by honeycomb-shaped Ni walls were prepared to form hard and glossy-colored films. The pigment/polymer Microdots were transferred onto bright Ni substrates using microcontact printing (μCP), and subsequently, electrodeposition of Ni was carried out to grow honeycomb Ni walls between the Microdots. The colors of the films could be controlled by the types of pigment used, and the colored films showed a glossy appearance because of the presence of the bright Ni substrate and the Ni walls, which are desirable properties in decorative surface finishing. Moreover, the films showed high film hardness. Because the height of the Ni walls was higher than that of the Microdots, the Ni walls protected the Microdots from physical damage, leading to excellent mechanical strength of the coatings in pencil hardness tests and adhesion tests.
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Microcontact printing of pigment/polymer composite Microdots and electrodeposition of Ni walls to fabricate hard and glossy-colored films
Surface and Coatings Technology, 2013Co-Authors: Hitoshi Ogihara, Hiro Kibayashi, Tetsuo SajiAbstract:Abstract Pigment/polymer composite Microdots surrounded by honeycomb-shaped Ni walls were prepared to form hard and glossy-colored films. The pigment/polymer Microdots were transferred onto bright Ni substrates using microcontact printing (μCP), and subsequently, electrodeposition of Ni was carried out to grow honeycomb Ni walls between the Microdots. The colors of the films could be controlled by the types of pigment used, and the colored films showed a glossy appearance because of the presence of the bright Ni substrate and the Ni walls, which are desirable properties in decorative surface finishing. Moreover, the films showed high film hardness. Because the height of the Ni walls was higher than that of the Microdots, the Ni walls protected the Microdots from physical damage, leading to excellent mechanical strength of the coatings in pencil hardness tests and adhesion tests.
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Hard and glossy-colored films composed of micropatterned organic dots and electrodeposited honeycomb-shaped nickel walls.
ACS Applied Materials & Interfaces, 2012Co-Authors: Hiro Kibayashi, Yosuke Hayano, Hitoshi Ogihara, Tetsuo SajiAbstract:This paper proposes a novel approach for the preparation of colored films with a metallic luster and high hardness. The colored organic films were patterned as Microdots by photolithography, and then honeycomb-shaped Ni walls were electrodeposited between the micropatterning. The organic/inorganic composite films showed the hardest grade in a pencil hardness test and high durability in wear resistance tests because the honeycomb-shaped Ni walls protected the colored organic dots.
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Hard and Glossy-Colored Films Composed of Micropatterned Organic Dots and Electrodeposited Honeycomb-Shaped Nickel Walls
2012Co-Authors: Hiro Kibayashi, Yosuke Hayano, Hitoshi Ogihara, Tetsuo SajiAbstract:This paper proposes a novel approach for the preparation of colored films with a metallic luster and high hardness. The colored organic films were patterned as Microdots by photolithography, and then honeycomb-shaped Ni walls were electrodeposited between the micropatterning. The organic/inorganic composite films showed the hardest grade in a pencil hardness test and high durability in wear resistance tests because the honeycomb-shaped Ni walls protected the colored organic dots
Youngbin Tchoe - One of the best experts on this subject based on the ideXlab platform.
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Free-standing and ultrathin inorganic light-emitting diode array
NPG Asia Materials, 2019Co-Authors: Youngbin Tchoe, Keundong Lee, Janghyun Jo, Kyungmin Chung, Miyoung Kim, Kunook Chung, Jerome K. Hyun, Gyu-chul YiAbstract:Light-emitting diodes: Free-standing, ultrathin, and high-resolution light sourcesA free-standing, ultrathin and flexible film of micrometer-scale semiconductor light sources has been created by scientists in South Korea. Light-emitting diodes are rapidly replacing less efficient alternatives in both lighting and displays but the traditional inorganic semiconductor materials they are made of are rigid, which means it is difficult to adapt them to applications requiring curved or flexible devices. Gyu-Chul Yi from the Seoul National University and co-workers developed uniquely addressable gallium nitride microdisk light-emitting diode arrays embedded in free-standing and ultrathin polyimide layers. Gallium nitride microdisk arrays they grew on graphene Microdots were easily released from the substrate due to the weak bond between the graphene and the underlying substrate. This approach could be used to create ultraflexible and high-resolution light-sources for wearable, medical or implantable device applications.AbstractWe report on the fabrication and characteristics of an individually addressable gallium nitride (GaN) microdisk light-emitting diode (LED) array in free-standing and ultrathin form. A high-quality GaN microdisk array with n -GaN, InGaN/GaN quantum wells and p -GaN layers was epitaxially grown on graphene Microdots patterned on SiO_2/Si substrates. Due to the weak attachment of the graphene Microdots to the growth substrate, a microdisk array coated with a polyimide layer was easily separated from the substrate using mechanical or chemical methods to form an ultrathin free-standing film. Individually addressable microdisk LEDs were created by forming thin metal contacts on the p -GaN and n -GaN surfaces in a crossbar configuration. Each microdisk LED that comprised an ultrahigh resolution array of 2500 pixels per inch was found to be uniquely addressable. The devices in free-standing form exhibited stable electrical and optoelectronic characteristics under extreme bending conditions and continuous operation mode despite the absence of a heat dissipating substrate. These results present promising approaches for the fabrication of high-quality inorganic semiconductor devices for ultrahigh resolution and high-performance flexible applications.We report on the fabrication and characteristics of an individually addressable GaN microdisk LED array in free-standing and ultrathin form. GaN microdisk array was grown on graphene Microdots, and the microstructures coated with a polyimide layer were easily separated from the substrate to form an ultrathin free-standing film. Crossbar configuration of metal leads enabled each microdisk LED in an array to be uniquely addressable. The devices in free-standing form exhibited stable electrical and optoelectronic characteristics under extreme bending conditions and continuous operation mode despite the absence of a heat dissipating substrate.
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Free-standing and ultrathin inorganic light-emitting diode array
NPG Asia Materials, 2019Co-Authors: Youngbin Tchoe, Janghyun Jo, Kyungmin Chung, Kunook Chung, Jerome K. Hyun, Gyu-chul YiAbstract:A free-standing, ultrathin and flexible film of micrometer-scale semiconductor light sources has been created by scientists in South Korea. Light-emitting diodes are rapidly replacing less efficient alternatives in both lighting and displays but the traditional inorganic semiconductor materials they are made of are rigid, which means it is difficult to adapt them to applications requiring curved or flexible devices. Gyu-Chul Yi from the Seoul National University and co-workers developed uniquely addressable gallium nitride microdisk light-emitting diode arrays embedded in free-standing and ultrathin polyimide layers. Gallium nitride microdisk arrays they grew on graphene Microdots were easily released from the substrate due to the weak bond between the graphene and the underlying substrate. This approach could be used to create ultraflexible and high-resolution light-sources for wearable, medical or implantable device applications. We report on the fabrication and characteristics of an individually addressable GaN microdisk LED array in free-standing and ultrathin form. GaN microdisk array was grown on graphene Microdots, and the microstructures coated with a polyimide layer were easily separated from the substrate to form an ultrathin free-standing film. Crossbar configuration of metal leads enabled each microdisk LED in an array to be uniquely addressable. The devices in free-standing form exhibited stable electrical and optoelectronic characteristics under extreme bending conditions and continuous operation mode despite the absence of a heat dissipating substrate. We report on the fabrication and characteristics of an individually addressable gallium nitride (GaN) microdisk light-emitting diode (LED) array in free-standing and ultrathin form. A high-quality GaN microdisk array with n -GaN, InGaN/GaN quantum wells and p -GaN layers was epitaxially grown on graphene Microdots patterned on SiO_2/Si substrates. Due to the weak attachment of the graphene Microdots to the growth substrate, a microdisk array coated with a polyimide layer was easily separated from the substrate using mechanical or chemical methods to form an ultrathin free-standing film. Individually addressable microdisk LEDs were created by forming thin metal contacts on the p -GaN and n -GaN surfaces in a crossbar configuration. Each microdisk LED that comprised an ultrahigh resolution array of 2500 pixels per inch was found to be uniquely addressable. The devices in free-standing form exhibited stable electrical and optoelectronic characteristics under extreme bending conditions and continuous operation mode despite the absence of a heat dissipating substrate. These results present promising approaches for the fabrication of high-quality inorganic semiconductor devices for ultrahigh resolution and high-performance flexible applications.
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Flexible GaN Light-Emitting Diodes Using GaN Microdisks Epitaxial Laterally Overgrown on Graphene Dots.
Advanced Materials, 2016Co-Authors: Kunook Chung, Jerome K. Hyun, Hongseok Oh, Youngbin Tchoe, Hyeonjun Baek, Gyu-chul YiAbstract:: The epitaxial lateral overgrowth (ELOG) of GaN microdisks on graphene Microdots and the fabrication of flexible light-emitting diodes (LEDs) using these microdisks is reported. An ELOG technique with only patterned graphene Microdots is used, without any growth mask. The discrete micro-LED arrays are transferred onto Cu foil by a simple lift-off technique, which works reliably under various bending conditions.
Kunook Chung - One of the best experts on this subject based on the ideXlab platform.
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Free-standing and ultrathin inorganic light-emitting diode array
NPG Asia Materials, 2019Co-Authors: Youngbin Tchoe, Keundong Lee, Janghyun Jo, Kyungmin Chung, Miyoung Kim, Kunook Chung, Jerome K. Hyun, Gyu-chul YiAbstract:Light-emitting diodes: Free-standing, ultrathin, and high-resolution light sourcesA free-standing, ultrathin and flexible film of micrometer-scale semiconductor light sources has been created by scientists in South Korea. Light-emitting diodes are rapidly replacing less efficient alternatives in both lighting and displays but the traditional inorganic semiconductor materials they are made of are rigid, which means it is difficult to adapt them to applications requiring curved or flexible devices. Gyu-Chul Yi from the Seoul National University and co-workers developed uniquely addressable gallium nitride microdisk light-emitting diode arrays embedded in free-standing and ultrathin polyimide layers. Gallium nitride microdisk arrays they grew on graphene Microdots were easily released from the substrate due to the weak bond between the graphene and the underlying substrate. This approach could be used to create ultraflexible and high-resolution light-sources for wearable, medical or implantable device applications.AbstractWe report on the fabrication and characteristics of an individually addressable gallium nitride (GaN) microdisk light-emitting diode (LED) array in free-standing and ultrathin form. A high-quality GaN microdisk array with n -GaN, InGaN/GaN quantum wells and p -GaN layers was epitaxially grown on graphene Microdots patterned on SiO_2/Si substrates. Due to the weak attachment of the graphene Microdots to the growth substrate, a microdisk array coated with a polyimide layer was easily separated from the substrate using mechanical or chemical methods to form an ultrathin free-standing film. Individually addressable microdisk LEDs were created by forming thin metal contacts on the p -GaN and n -GaN surfaces in a crossbar configuration. Each microdisk LED that comprised an ultrahigh resolution array of 2500 pixels per inch was found to be uniquely addressable. The devices in free-standing form exhibited stable electrical and optoelectronic characteristics under extreme bending conditions and continuous operation mode despite the absence of a heat dissipating substrate. These results present promising approaches for the fabrication of high-quality inorganic semiconductor devices for ultrahigh resolution and high-performance flexible applications.We report on the fabrication and characteristics of an individually addressable GaN microdisk LED array in free-standing and ultrathin form. GaN microdisk array was grown on graphene Microdots, and the microstructures coated with a polyimide layer were easily separated from the substrate to form an ultrathin free-standing film. Crossbar configuration of metal leads enabled each microdisk LED in an array to be uniquely addressable. The devices in free-standing form exhibited stable electrical and optoelectronic characteristics under extreme bending conditions and continuous operation mode despite the absence of a heat dissipating substrate.
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Free-standing and ultrathin inorganic light-emitting diode array
NPG Asia Materials, 2019Co-Authors: Youngbin Tchoe, Janghyun Jo, Kyungmin Chung, Kunook Chung, Jerome K. Hyun, Gyu-chul YiAbstract:A free-standing, ultrathin and flexible film of micrometer-scale semiconductor light sources has been created by scientists in South Korea. Light-emitting diodes are rapidly replacing less efficient alternatives in both lighting and displays but the traditional inorganic semiconductor materials they are made of are rigid, which means it is difficult to adapt them to applications requiring curved or flexible devices. Gyu-Chul Yi from the Seoul National University and co-workers developed uniquely addressable gallium nitride microdisk light-emitting diode arrays embedded in free-standing and ultrathin polyimide layers. Gallium nitride microdisk arrays they grew on graphene Microdots were easily released from the substrate due to the weak bond between the graphene and the underlying substrate. This approach could be used to create ultraflexible and high-resolution light-sources for wearable, medical or implantable device applications. We report on the fabrication and characteristics of an individually addressable GaN microdisk LED array in free-standing and ultrathin form. GaN microdisk array was grown on graphene Microdots, and the microstructures coated with a polyimide layer were easily separated from the substrate to form an ultrathin free-standing film. Crossbar configuration of metal leads enabled each microdisk LED in an array to be uniquely addressable. The devices in free-standing form exhibited stable electrical and optoelectronic characteristics under extreme bending conditions and continuous operation mode despite the absence of a heat dissipating substrate. We report on the fabrication and characteristics of an individually addressable gallium nitride (GaN) microdisk light-emitting diode (LED) array in free-standing and ultrathin form. A high-quality GaN microdisk array with n -GaN, InGaN/GaN quantum wells and p -GaN layers was epitaxially grown on graphene Microdots patterned on SiO_2/Si substrates. Due to the weak attachment of the graphene Microdots to the growth substrate, a microdisk array coated with a polyimide layer was easily separated from the substrate using mechanical or chemical methods to form an ultrathin free-standing film. Individually addressable microdisk LEDs were created by forming thin metal contacts on the p -GaN and n -GaN surfaces in a crossbar configuration. Each microdisk LED that comprised an ultrahigh resolution array of 2500 pixels per inch was found to be uniquely addressable. The devices in free-standing form exhibited stable electrical and optoelectronic characteristics under extreme bending conditions and continuous operation mode despite the absence of a heat dissipating substrate. These results present promising approaches for the fabrication of high-quality inorganic semiconductor devices for ultrahigh resolution and high-performance flexible applications.
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Flexible GaN Light-Emitting Diodes Using GaN Microdisks Epitaxial Laterally Overgrown on Graphene Dots.
Advanced Materials, 2016Co-Authors: Kunook Chung, Jerome K. Hyun, Hongseok Oh, Youngbin Tchoe, Hyeonjun Baek, Gyu-chul YiAbstract:: The epitaxial lateral overgrowth (ELOG) of GaN microdisks on graphene Microdots and the fabrication of flexible light-emitting diodes (LEDs) using these microdisks is reported. An ELOG technique with only patterned graphene Microdots is used, without any growth mask. The discrete micro-LED arrays are transferred onto Cu foil by a simple lift-off technique, which works reliably under various bending conditions.
Hiroyuki Niino - One of the best experts on this subject based on the ideXlab platform.
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High-resolution printing of functional Microdots by double-pulse laser-induced forward transfer
Laser Applications in Microelectronic and Optoelectronic Manufacturing (LAMOM) XX, 2015Co-Authors: Aiko Narazaki, Ryozo Kurosaki, Tadatake Sato, Hiroyuki NiinoAbstract:For high-resolution printing, we have developed a novel way of functional Microdots deposition based on laser-induced forward transfer, which is referred to laser-induced dot transfer (LIDT). LIDT is one of promising additive manufacturing techniques because it can realize flexible patterning of micron and submicron-sized dots at atmospheric room-temperature conditions. Recently we have achieved printing of functional oxide Microdots by a double-pulse LIDT with the first pulse for preheat and the second pulse for transfer, resulting in more precise control of laser-induced hightemperature and thermal-stress in a source film. In this paper, temporal temperature distributions during the transfer process have been investigated using a finite element method approach. High-resolution printing of functional Microdots is promising for future optoelectronic integrations.
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On-Demand Deposition of Functional Oxide Microdots by Double-Pulse Laser-Induced Dot Transfer
Journal of Laser Micro Nanoengineering, 2014Co-Authors: Aiko Narazaki, Ryozo Kurosaki, Tadatake Sato, Yoshizo Kawaguchi, Hiroyuki NiinoAbstract:We have newly developed a double-pulse laser-induced dot transfer technique to realize ondemand deposition of functional oxide Microdots under room-temperature atmospheric conditions. In our double-pulse system, the first pulse was irradiated to preheat an oxide source film, and then the second pulse was more tightly focused on the same position to deposit an oxide microdot onto a receiver substrate. As a model case, indium tin oxide Microdots with much smaller lateral dimensions than the laser focal area were reproducibly arrayed on a silica glass substrate by the doublepulse process, while there were microdot vacancies at a rate of approximately 30 % in the case of a single-pulse process without preheating. In order to explore the effect of double-pulse, laser-induced temperature distribution was also investigated from a finite elemental approach.
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Flexible Patterning of Functional Microdot by Laser-Induced Dot Transfer
Journal of Laser Micro Nanoengineering, 2014Co-Authors: Aiko Narazaki, Ryozo Kurosaki, Tadatake Sato, Hiroyuki NiinoAbstract:Laser-induced dot transfer (LIDT) is one of promising additive manufacturing techniques because it can realize flexible patterning of micron and submicron-sized dots even at atmospheric room-temperature conditions. In the LIDT process, a laser pulse is tightly focused onto a source film, leading to a transient melting of the film followed by sub-spot transfer using one-to-one microdot deposition with laser-illuminated area. Recently, we have developed a novel double-pulse LIDT process using the first pulse for preheating the source film and the second pulse for dot transfer. To investigate the double-pulse effect on microdot transfer of oxides, temporal high-temperature distributions of a thick indium tin oxide source film during double-pulse irradiation have been simulated using a Finite Element Method (FEM) approach. As a result, preheating by the first pulse decreased a difference in film temperature along both the film thickness and in-plane directions. This is effective to avoid film fracture, leading to high-quality patterning of a wide variety of Microdots.
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On-Demand Patterning of Indium Tin Oxide Microdots by Laser-Induced Dot Transfer
Applied Physics Express, 2013Co-Authors: Aiko Narazaki, Ryozo Kurosaki, Tadatake Sato, Hiroyuki NiinoAbstract:Laser-induced dot transfer is an innovative micropatterning technique that realizes on-demand microdot deposition under room-temperature atmospheric conditions. Based on this method, we have developed site- and size-controlled micropatterning of oxide materials. As a model case, indium tin oxide (ITO) Microdots were arrayed on a receiver substrate. A nanosecond, 266 nm laser pulse was focused onto the interface between the ITO film and transparent support, causing the ejection of a single ITO microdroplet. The dependence of the transferred structures on the film thickness as well as the laser-induced film temperature distribution has been investigated by both experimental and finite elemental approaches.
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Nano- and microdot array formation by laser-induced dot transfer
Applied Surface Science, 2009Co-Authors: Aiko Narazaki, Ryozo Kurosaki, Tadatake Sato, Yoshizo Kawaguchi, Hiroyuki NiinoAbstract:Abstract Fabrication of FeSi2 nano- and microdot array was performed by utilizing droplet ejection through laser-induced forward transfer, which we named laser-induced dot transfer (LIDT). An amorphous FeSi2 alloy source film on a transparent support was illuminated from the support by a nanosecond excimer laser pulse patterned into migcrogrid form, resulting in size- and site-controlled dot deposition. Micro-Raman spectroscopy confirmed β-FeSi2 semiconducting crystalline phase even on unheated substrates. Moreover, the Microdots exhibited near-infrared photoluminescence at the peak wavelength of 1.57 μm, which comes from the β-FeSi2 crystalline phase precipitated during the LIDT process. The dot size was successfully reduced to approximately 500 and 300 nm in diameter and height, respectively. This technique is useful for integrating functional nano- and Microdots under atmospheric room-temperature conditions.