Patents by Inventor Takeyoshi Watabe
Takeyoshi Watabe has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 9461259Abstract: Provided is a light-emitting element having a light-emitting layer which contains at least a host material and a plurality of guest materials, where the host material has a lower T1 level than that of at least one of the plurality of guest materials. The emission of the one of the plurality of guest materials exhibits a multicomponent decay curve, and the lifetime thereof is less than or equal to 15 ?sec, preferably less than or equal to 10 ?sec, more preferably less than or equal to 5 ?sec, where the lifetime is defined as a time for the emission to decrease in intensity to 1/100 of its initial intensity.Type: GrantFiled: May 21, 2015Date of Patent: October 4, 2016Assignee: Semiconductor Energy Laboratory Co., Ltd.Inventors: Takeyoshi Watabe, Satoshi Seo
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Patent number: 9444063Abstract: To increase emission efficiency of a fluorescent light-emitting element by efficiently utilizing a triplet exciton generated in a light-emitting layer. The light-emitting layer of the light-emitting element includes at least a host material and a guest material. The triplet exciton generated from the host material in the light-emitting layer is changed to a singlet exciton by triplet-triplet annihilation (TTA). The guest material (fluorescent dopant) is made to emit light by energy transfer from the singlet exciton. Thus, the emission efficiency of the light-emitting element is improved.Type: GrantFiled: May 13, 2014Date of Patent: September 13, 2016Assignee: Semiconductor Energy Laboratory Co., Ltd.Inventors: Yusuke Nonaka, Satoshi Seo, Harue Osaka, Tsunenori Suzuki, Takeyoshi Watabe
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Patent number: 9391290Abstract: A light-emitting element of the present invention can have sufficiently high emission efficiency with a structure including a host material being able to remain chemically stable even if a phosphorescent compound having higher emission energy is used as a guest material. The relation between the relative emission intensity and the emission time of light emission obtained from the host material and the guest material contained in a light-emitting layer is represented by a multicomponent decay curve. The relative emission intensity of the slowest component of the multicomponent decay curve becomes 1/100 for a short time within a range where the slowest component is not interfered with by quenching of the host material (the emission time of the slowest component is preferably less than or equal to 15 ?sec); thus, sufficiently high emission efficiency can be obtained.Type: GrantFiled: January 8, 2014Date of Patent: July 12, 2016Assignee: Semiconductor Energy Laboratory Co., Ltd.Inventors: Takeyoshi Watabe, Satoshi Seo
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Publication number: 20160190500Abstract: A light-emitting element that emits light with high color purity, a light-emitting element that emits light at high emission efficiency, or a light-emitting element with reduced power consumption. The light-emitting element includes a first electrode, a second electrode, and an EL layer. The first electrode is configured to reflect light. The second electrode is configured to reflect light and transmit light. The EL layer is between the first electrode and the second electrode. The EL layer includes a guest material. The guest material is configured to convert triplet excitation energy into light emission. The emission spectrum of the guest material in a dichloromethane solution has a peak in a wavelength region ranging from 440 nm to 470 nm and has a full width at half maximum of greater than or equal to 20 nm and less than or equal to 80 nm.Type: ApplicationFiled: December 22, 2015Publication date: June 30, 2016Applicant: Semiconductor Energy Laboratory Co., Ltd.Inventors: Takeyoshi WATABE, Toshiki SASAKI, Satoshi SEO
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Publication number: 20160118615Abstract: To provide a novel light-emitting element or a highly reliable light-emitting element. To provide a light-emitting device, a display device, an electronic device, and a lighting device each of which can be manufactured at a low cost. To provide a light-emitting element including an anode, a cathode, and an EL layer between the anode and the cathode. The EL layer includes a light-emitting layer and an electron injection transport layer between the light-emitting layer and the cathode, and the amount of a halogen detected from a material forming the electron injection transport layer is less than or equal to 30 ppm.Type: ApplicationFiled: October 26, 2015Publication date: April 28, 2016Inventors: Satoshi SEO, Tsunenori SUZUKI, Takeyoshi WATABE, Kunihiko SUZUKI, Toshiki HAMADA, Rina NAKAMURA, Hayato YAMAWAKI, Ayumi SATO, Harue OSAKA
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Publication number: 20160118614Abstract: A novel light-emitting element or a highly reliable light-emitting element is provided. The light-emitting element includes an anode, a cathode, and an EL layer between the anode and the cathode. The EL layer includes at least a light-emitting layer. The light-emitting layer includes at least a first organic compound and a second organic compound. The energy for liberating halogen from a halogen-substituted product of the first organic compound in a radical anion state and in a triplet excited state is less than or equal to 1.00 eV. The amount of halogen-substituted product in the second organic compound is not increased with an increase in driving time of the light-emitting element.Type: ApplicationFiled: October 14, 2015Publication date: April 28, 2016Inventors: Satoshi SEO, Takeyoshi WATABE, Rina NAKAMURA, Harue OSAKA, Ayumi SATO, Kunihiko SUZUKI, Hayato YAMAWAKI
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Publication number: 20160093823Abstract: Provided is a light-emitting element including a fluorescence-emitting material with high emission efficiency. The light-emitting element includes a pair of electrodes and an EL layer between the pair of electrodes. The EL layer includes a first organic compound, a second organic compound, and a guest material. The first organic compound has a function of emitting a thermally activated delayed fluorescence at room temperature. The guest material has a function of emitting fluorescence. A HOMO level of the first organic compound higher than or equal to a HOMO level of the second organic compound. A LUMO level of the first organic compound is lower than or equal to a LUMO level of the second organic compound.Type: ApplicationFiled: September 29, 2015Publication date: March 31, 2016Inventors: Satoshi Seo, Nobuharu Ohsawa, Takeyoshi Watabe
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Publication number: 20150255742Abstract: Provided is a light-emitting element having a light-emitting layer which contains at least a host material and a plurality of guest materials, where the host material has a lower T1 level than that of at least one of the plurality of guest materials. The emission of the one of the plurality of guest materials exhibits a multicomponent decay curve, and the lifetime thereof is less than or equal to 15 pec, preferably less than or equal to 10 pec, more preferably less than or equal to 5 pec, where the lifetime is defined as a time for the emission to decrease in intensity to 1/100 of its initial intensity.Type: ApplicationFiled: May 21, 2015Publication date: September 10, 2015Inventors: Takeyoshi WATABE, Satoshi SEO
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Patent number: 9082994Abstract: Provided is a light-emitting element having a light-emitting layer which contains at least a host material and a plurality of guest materials, where the host material has a lower T1 level than that of at least one of the plurality of guest materials. The emission of the one of the plurality of guest materials exhibits a multicomponent decay curve, and the lifetime thereof is less than or equal to 15 ?sec, preferably less than or equal to 10 ?sec, more preferably less than or equal to 5 ?sec, where the lifetime is defined as a time for the emission to decrease in intensity to 1/100 of its initial intensity.Type: GrantFiled: March 20, 2014Date of Patent: July 14, 2015Assignee: Semiconductor Energy Laboratory Co., Ltd.Inventors: Takeyoshi Watabe, Satoshi Seo
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Publication number: 20140339522Abstract: To increase emission efficiency of a fluorescent light-emitting element by efficiently utilizing a triplet exciton generated in a light-emitting layer. The light-emitting layer of the light-emitting element includes at least a host material and a guest material. The triplet exciton generated from the host material in the light-emitting layer is changed to a singlet exciton by triplet-triplet annihilation (TTA). The guest material (fluorescent dopant) is made to emit light by energy transfer from the singlet exciton. Thus, the emission efficiency of the light-emitting element is improved.Type: ApplicationFiled: May 13, 2014Publication date: November 20, 2014Applicant: SEMICONDUCTOR ENERGY LABORATORY CO., LTD.Inventors: Yusuke NONAKA, Satoshi SEO, Harue OSAKA, Tsunenori SUZUKI, Takeyoshi WATABE
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Publication number: 20140339524Abstract: Provided is a light-emitting element which has an anode, a light-emitting layer over the anode, an electron-transport layer over and in contact with the light-emitting layer, an electron-injection layer over and in contact with the electron-transport layer, and a cathode over and in contact with the electron-injection layer. The light-emitting layer has an electron-transport property, and the electron-transport layer includes an anthracene derivative. The light-emitting layer further includes a phosphorescent substance. This device structure allows the formation of a highly efficient blue-emissive light-emitting element even though the phosphorescent substance has higher triplet energy than the anthracene derivative which directly contacts with the light-emitting layer.Type: ApplicationFiled: May 14, 2014Publication date: November 20, 2014Applicant: SEMICONDUCTOR ENERGY LABORATORY CO., LTD.Inventors: Satoko SHITAGAKI, Takahiro ISHISONE, Satoshi SEO, Takeyoshi WATABE
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Publication number: 20140291642Abstract: Provided is a light-emitting element having a light-emitting layer which contains at least a host material and a plurality of guest materials, where the host material has a lower T1 level than that of at least one of the plurality of guest materials. The emission of the one of the plurality of guest materials exhibits a multicomponent decay curve, and the lifetime thereof is less than or equal to 15 ?sec, preferably less than or equal to 10 ?sec, more preferably less than or equal to 5 ?sec, where the lifetime is defined as a time for the emission to decrease in intensity to 1/100 of its initial intensity.Type: ApplicationFiled: March 20, 2014Publication date: October 2, 2014Applicant: Semiconductor Energy Laboratory Co., Ltd.Inventors: Takeyoshi WATABE, Satoshi SEO
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Publication number: 20140191220Abstract: A light-emitting element of the present invention can have sufficiently high emission efficiency with a structure including a host material being able to remain chemically stable even if a phosphorescent compound having higher emission energy is used as a guest material. The relation between the relative emission intensity and the emission time of light emission obtained from the host material and the guest material contained in a light-emitting layer is represented by a multicomponent decay curve. The relative emission intensity of the slowest component of the multicomponent decay curve becomes 1/100 for a short time within a range where the slowest component is not interfered with by quenching of the host material (the emission time of the slowest component is preferably less than or equal to 15 ?sec); thus, sufficiently high emission efficiency can be obtained.Type: ApplicationFiled: January 8, 2014Publication date: July 10, 2014Applicant: Semiconductor Energy Laboratory Co., Ltd.Inventors: Takeyoshi Watabe, Satoshi Seo
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Patent number: 8604481Abstract: A thin film transistor includes a gate insulating layer covering a gate electrode, a semiconductor layer in contact with the gate insulating layer, and impurity semiconductor layers which are in contact with part of the semiconductor layer and which form a source region and a drain region. The semiconductor layer includes a microcrystalline semiconductor layer formed on the gate insulating layer and a microcrystalline semiconductor region containing nitrogen in contact with the microcrystalline semiconductor layer. The thin film transistor in which off-current is small and on-current is large can be manufactured with high productivity.Type: GrantFiled: October 3, 2012Date of Patent: December 10, 2013Assignee: Semiconductor Energy Co., Ltd.Inventors: Hidekazu Miyairi, Takeyoshi Watabe, Takashi Shimazu
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Patent number: 8304775Abstract: A thin film transistor includes a gate insulating layer covering a gate electrode, a semiconductor layer in contact with the gate insulating layer, and impurity semiconductor layers which are in contact with part of the semiconductor layer and which form a source region and a drain region. The semiconductor layer includes a microcrystalline semiconductor layer formed on the gate insulating layer and a microcrystalline semiconductor region containing nitrogen in contact with the microcrystalline semiconductor layer. The thin film transistor in which off-current is small and on-current is large can be manufactured with high productivity.Type: GrantFiled: March 2, 2010Date of Patent: November 6, 2012Assignee: Semiconductor Energy Laboratory Co., Ltd.Inventors: Hidekazu Miyairi, Takeyoshi Watabe, Takashi Shimazu
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Patent number: 8124972Abstract: The thin film transistor includes a gate insulating layer covering a gate electrode, over a substrate having an insulating surface; a semiconductor layer forming a channel formation region, in which a plurality of crystal regions is included in an amorphous structure; an impurity semiconductor layer imparting one conductivity type which forms a source region and a drain region; and a buffer layer formed from an amorphous semiconductor, which is located between the semiconductor layer and the impurity semiconductor layer. The thin film transistor includes the crystal region which includes minute crystal grains and inverted conical or inverted pyramidal grain each of which grows approximately radially from a position away from an interface between the gate insulating layer and the semiconductor layer toward a direction in which the semiconductor layer is deposited in a region which does not reach the impurity semiconductor layer.Type: GrantFiled: April 24, 2009Date of Patent: February 28, 2012Assignee: Semiconductor Energy Laboratory Co., Ltd.Inventors: Koji Dairiki, Hidekazu Miyairi, Toshiyuki Isa, Akiharu Miyanaga, Takuya Hirohashi, Shunpei Yamazaki, Takeyoshi Watabe
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Publication number: 20100224879Abstract: A thin film transistor includes a gate insulating layer covering a gate electrode, a semiconductor layer in contact with the gate insulating layer, and impurity semiconductor layers which are in contact with part of the semiconductor layer and which form a source region and a drain region. The semiconductor layer includes a microcrystalline semiconductor layer formed on the gate insulating layer and a microcrystalline semiconductor region containing nitrogen in contact with the microcrystalline semiconductor layer. The thin film transistor in which off-current is small and on-current is large can be manufactured with high productivity.Type: ApplicationFiled: March 2, 2010Publication date: September 9, 2010Applicant: SEMICONDUCTOR ENERGY LABORATORY CO., LTD.Inventors: Hidekazu MIYAIRI, Takeyoshi WATABE, Takashi SHIMAZU
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Publication number: 20090267068Abstract: The thin film transistor includes a gate insulating layer covering a gate electrode, over a substrate having an insulating surface; a semiconductor layer forming a channel formation region, in which a plurality of crystal regions is included in an amorphous structure; an impurity semiconductor layer imparting one conductivity type which forms a source region and a drain region; and a buffer layer formed from an amorphous semiconductor, which is located between the semiconductor layer and the impurity semiconductor layer. The thin film transistor includes the crystal region which includes minute crystal grains and inverted conical or inverted pyramidal grain each of which grows approximately radially from a position away from an interface between the gate insulating layer and the semiconductor layer toward a direction in which the semiconductor layer is deposited in a region which does not reach the impurity semiconductor layer.Type: ApplicationFiled: April 24, 2009Publication date: October 29, 2009Applicant: SEMICONDUCTOR ENERGY LABORATORY CO., LTD.Inventors: Koji DAIRIKI, Hidekazu MIYAIRI, Toshiyuki ISA, Akiharu MIYANAGA, Takuya HIROHASHI, Shunpei YAMAZAKI, Takeyoshi WATABE