Provided is a semiconductor nanoparticle complex having both improved fluorescence quantum yield and improved heat resistance. A semiconductor nanoparticle complex according to an embodiment includes a semiconductor nanoparticle complex in which two or more ligands including a ligand I and a ligand II are coordinated to the surface of a semiconductor nanoparticle, wherein: the ligands are composed of an organic group and a coordinating group; the ligand I has one mercapto group as the coordinating group; and the ligand II has at least two or more mercapto groups as the coordinating groups.

Provided is a Cd-free blue fluorescent quantum dot with a narrow fluorescence FWHM. The quantum dot does not contain cadmium and its fluorescence FWHM is 25 nm or less. The quantum dot is preferably a nanocrystal containing zinc and selenium or zinc and selenium and sulfur. Further, the quantum dot preferably has a core-shell structure in which the nanocrystal serves as a core and the surface of the core is coated with a shell.

A quantum dot light-emitting diode and a method for fabricating the same. The quantum dot light-emitting diode, includes: an anode, a cathode, and a quantum dot light-emitting layer arranged between the anode and the cathode. A composite electron transport layer is arranged between the cathode and the quantum dot light-emitting layer, and the composite electron transport layer contains an electron transport material and an ultraviolet absorbing material.

A quantum dot light-emitting diode and a method for fabricating the same. The quantum dot light-emitting diode, includes: an anode, a cathode, and a quantum dot light-emitting layer arranged between the anode and the cathode. A composite electron transport layer is arranged between the cathode and the quantum dot light-emitting layer, and the composite electron transport layer contains an electron transport material and an ultraviolet absorbing material.

An object is to provide a quantum dot that has a narrow fluorescence half-width and a high fluorescence quantum yield, and emits blue fluorescence. A quantum dot (5) according to the present invention includes at least Zn and Se and does not include Cd, and has a particle diameter of 5 nm or more and 20 nm or less. In addition, the quantum dot (5) according to the present invention includes at least Zn and Se and does not include Cd, and has a fluorescence quantum yield of 5% or more and a fluorescence half-width of 25 nm or less. In the present invention, the fluorescence lifetime can be made 50 ns or less.

An object is to provide a quantum dot that has a narrow fluorescence half-width and a high fluorescence quantum yield, and emits blue fluorescence. A quantum dot (5) according to the present invention includes at least Zn and Se and does not include Cd, and has a particle diameter of 5 nm or more and 20 nm or less. In addition, the quantum dot (5) according to the present invention includes at least Zn and Se and does not include Cd, and has a fluorescence quantum yield of 5% or more and a fluorescence half-width of 25 nm or less. In the present invention, the fluorescence lifetime can be made 50 ns or less.

A quantum dot has a fluorescent crystalline nanoparticle, wherein the quantum dot has a core-shell structure including a core particle containing a first metal element and a shell layer containing a second metal element, at an interface between the core particle and the shell layer, a third metal element different from the first metal element and the second metal element is present, and an amount of the third metal element with respect to an amount of the first metal element contained in the core particle is 10% or less in terms of molar ratio. As a result the quantum dot has excellent controllability of the emission wavelength and high luminous properties and luminous efficiency.

Ultrasensitive, miniaturized, and inexpensive ion and ionizing radiation detection devices are provided. The devices include an insulating substrate, metallic contact pads disposed on a surface of the substrate, and a strip of an ultrathin two-dimensional material having a thickness of one or a few atomic layers. The strip is in contact with the contact pads, and a voltage is applied across the two-dimensional sensor material. Individual ions contacting the two-dimensional material alter the current flowing through the material and are detected. The devices can be used in a network of monitors for high energy ions and ionizing radiation.

Methods, systems, and devices for chalcogenide memory device compositions are described. A memory cell may use a chalcogenide material having a composition as described herein as a storage materials, a selector materials, or as a self-selecting storage material. A chalcogenide material as described herein may include a sulfurous component, which may be completely sulfur (S) or may be a combination of sulfur and one or more other elements, such as selenium (Se). In addition to the sulfurous component, the chalcogenide material may further include one or more other elements, such as germanium (Ge), at least one Group-III element, or arsenic (As).

Methods, systems, and devices for chalcogenide memory device compositions are described. A memory cell may use a chalcogenide material having a composition as described herein as a storage materials, a selector materials, or as a self-selecting storage material. A chalcogenide material as described herein may include a sulfurous component, which may be completely sulfur (S) or may be a combination of sulfur and one or more other elements, such as selenium (Se). In addition to the sulfurous component, the chalcogenide material may further include one or more other elements, such as germanium (Ge), at least one Group-III element, or arsenic (As).