A photoelectric conversion element includes: a first electrode and a second electrode; a photoelectric conversion layer between the first electrode and the second electrode; and a carrier transport layer between the photoelectric conversion layer and the second electrode, the carrier transport layer containing a plurality of carrier transport particles and a plurality of organic ligands, the carrier transport layer having a first end potion located close to the photoelectric conversion layer in a thickness direction of the carrier transport layer and a second end potion located close to the second electrode in the thickness direction of the carrier transport layer, wherein a first minimum distance between the plurality of carrier transport particles in the first end potion and the photoelectric conversion layer is larger than a second minimum distance between the plurality of carrier transport materials particles in the second end potion and the second electrode.

A quantum dots light emitting diode is provided. The quantum dots light emitting diode includes a first electrode layer; an electron transport layer on the first electrode layer; and a quantum dots layer on a side of the electron transport layer away from the first electrode layer. The electron transport layer includes a gradient alloy composite sub-layer including an electron transport oxide material and an electron transport non-oxide chalcogen-containing material. The non-oxide chalcogen is selected from a group consisting of sulfide ion, selenium ion, and tellurium ion. The electron transport non-oxide chalcogen-containing material has a gradient distribution such that a content of the electron transport non-oxide chalcogen-containing material decreases along a direction from the quantum dots layer to the first electrode layer.

A quantum dots light emitting diode is provided. The quantum dots light emitting diode includes a first electrode layer; an electron transport layer on the first electrode layer; a quantum dots layer on a side of the electron transport layer away from the first electrode layer, and a non-oxide chalcogen-containing compound between the first electrode layer and the quantum dot layer. The non-oxide chalcogen-containing compound includes a metal element and a non-oxide chalcogen. The non-oxide chalcogen is selected from a group consisting of sulfide ion, selenium ion, and tellurium ion.

A light-emitting device includes: a first electrode and a second electrode that are superposed; a light-emitting layer (EML) located between the first electrode and the second electrode; and an electron transport layer (ETL) located between the first electrode and the EML. The ETL includes a first surface proximate to the EML and a second surface proximate to the first electrode, the ETL includes oxygen vacancies, and a concentration of oxygen vacancies in the first surface is greater than a concentration of oxygen vacancies in the second surface.

A light-emitting element includes: a first electrode; a second electrode; and a quantum-dot layer; provided between the first electrode and the second electrode. The quantum-dot layer contains a plurality of quantum dots including at least cores, and an inorganic filler material filling spaces between the plurality of quantum dots. At least a portion of a composition of the quantum-dot layer around at least one core has a concentration gradient in a direction from toward a center of the core to toward around the core.