A light emitting device includes light emitting element(s). A light transmissive member is on an upper surface of the light emitting element(s). An upper surface area of the light transmissive member is smaller than a lower surface area of the light transmissive member. The upper surface area of the light transmissive member is smaller than a sum of upper surface areas of each light emitting element(s). The lower surface area of the light transmissive member is larger than the sum of the upper surface areas of each light emitting element(s). A light reflective member is provided having a first light reflective member and an underfill. The first light reflective member covers surfaces of the light transmissive member and lateral surfaces of the light emitting element(s) to expose the upper surface of the light transmissive member. The underfill covers the lateral and lower surfaces of each light emitting element(s).

A light emitting device includes light emitting element(s). A light transmissive member is on an upper surface of the light emitting element(s). An upper surface area of the light transmissive member is smaller than a lower surface area of the light transmissive member. The upper surface area of the light transmissive member is smaller than a sum of upper surface areas of each light emitting element(s). The lower surface area of the light transmissive member is larger than the sum of the upper surface areas of each light emitting element(s). A light reflective member is provided having a first light reflective member and an underfill. The first light reflective member covers surfaces of the light transmissive member and lateral surfaces of the light emitting element(s) to expose the upper surface of the light transmissive member. The underfill covers the lateral and lower surfaces of each light emitting element(s).

A light-emitting element according to the present disclosure includes an anode, a hole transport layer, and a light-emitting layer containing a quantum dot, and a cathode in this order, and the hole transport layer includes an n+-type semiconductor layer, and a p+-type semiconductor layer adjacent to the n+-type semiconductor layer and disposed closer to the light-emitting layer than the n+-type semiconductor layer.

A light emitting device including a substrate having a protruding pattern on an upper surface thereof, a first sub-unit disposed on the substrate, a second sub-unit disposed between the substrate and the first sub-unit, a third sub-unit disposed between the substrate and the second sub-unit, a first insulation layer at least partially in contact with side surfaces of the first, second, and third sub-units, and a second insulation layer at least partially overlapping with the first insulation layer, in which at least one of the first insulation layer and the second insulation layer includes a distributed Bragg reflector.

A quantum dot of a light emitting device, includes: a core; and a shell around the core and including halogen elements of at least one type, wherein a first number per unit volume of halogen elements in a first area of the shell, that includes an outer surface of the shell, is larger than a second number per unit volume of halogen elements in a second area of the shell other than the outer surface of the shell.

A quantum dot of a light emitting device, includes: a core; and a shell around the core and including halogen elements of at least one type, wherein a first number per unit volume of halogen elements in a first area of the shell, that includes an outer surface of the shell, is larger than a second number per unit volume of halogen elements in a second area of the shell other than the outer surface of the shell.

Methods of generating light are provided comprising applying an electrical bias to an active region of a quantum dot cascade light emitting device comprising: the active region comprising a film of close-packed, doped, colloidal quantum dots, the quantum dots comprising a core semiconductor characterized by an energy band having quantum states defining an intraband transition between a high energy quantum state and a low energy quantum state, and a pair of electrodes configured to apply the electrical bias, wherein the active region emits light under the electrical bias as carriers undergo the intraband transitions in the core semiconductor of quantum dots in the film, tunnel to other quantum dots in the film, and undergo additional intraband transitions in the core semiconductor of the other quantum dots in the film. The quantum dot cascade light emitting devices are also provided.

Methods of generating light are provided comprising applying an electrical bias to an active region of a quantum dot cascade light emitting device comprising: the active region comprising a film of close-packed, doped, colloidal quantum dots, the quantum dots comprising a core semiconductor characterized by an energy band having quantum states defining an intraband transition between a high energy quantum state and a low energy quantum state, and a pair of electrodes configured to apply the electrical bias, wherein the active region emits light under the electrical bias as carriers undergo the intraband transitions in the core semiconductor of quantum dots in the film, tunnel to other quantum dots in the film, and undergo additional intraband transitions in the core semiconductor of the other quantum dots in the film. The quantum dot cascade light emitting devices are also provided.

A light-emitting element includes: an anode and a cathode; and a quantum dot layer positioned between the anode and the cathode, the quantum dot layer including a first quantum dot and a second quantum dot. The quantum dot layer includes a crystalline body serving as a core of the first quantum dot, and an inorganic amorphous material formed at at least a part of a surface of the crystalline body.

A light-emitting element includes: an anode and a cathode; and a quantum dot layer positioned between the anode and the cathode, the quantum dot layer including a first quantum dot and a second quantum dot. The quantum dot layer includes a crystalline body serving as a core of the first quantum dot, and an inorganic amorphous material formed at at least a part of a surface of the crystalline body.