Abstract: The present disclosure relates to an organic electroluminescent device. The organic electroluminescent device of the present disclosure shows high luminous efficiency and good lifespan by comprising a specific combination of the plural kinds of host compounds and a specific hole transport compound.

Abstract: A semiconductor device includes a first active pattern including a first lower pattern and first sheet patterns; a second active pattern including a second lower pattern and second sheet patterns, a height of the second lower pattern being smaller than a height of the first lower pattern; a first gate structure on the first lower pattern; a second gate structure on the second lower pattern; a first source/drain pattern on the first lower pattern and connected to the first sheet patterns; and a second source/drain pattern on the second lower pattern and connected to the second sheet patterns, wherein a width of an upper surface of the first lower pattern is different from a width of an upper surface of the second lower pattern, and wherein a number of first sheet patterns is different from a number of second sheet patterns.

Abstract: The present disclosure relates to an organic electroluminescent device. The organic electroluminescent device of the present disclosure shows high luminous efficiency and good lifespan by comprising a specific combination of the plural kinds of host compounds and a specific hole transport compound.

Abstract: A semiconductor package and or method of fabricating the semiconductor package may be provided. The semiconductor package may include a first die, at least one second die electrically connected to the first die, and a plurality of first connectors disposed on the interconnection structure layer. The semiconductor package may include a package substrate electrically connected to the plurality of first connectors. The package substrate may have a cavity and the at least one second die is at least partially disposed in the cavity. The interconnection structure layer may include signal paths electrically connected to the first die and to the at least one second die. The at least one second die may be positioned to minimize a length of the signal paths.