Quantum dot device and electronic device

A quantum dot device, comprising

• a first electrode and a second electrode,
• a light emitting layer between the first electrode and the second electrode, the light emitting layer comprising quantum dots,
• a buffer layer between the second electrode and the light emitting layer, the buffer layer comprising a first electron transport material and a hole extraction material, and
• a first charge auxiliary layer between the second electrode and the light emitting layer, the first charge auxiliary layer comprising a second electron transport material that is the same as or different from the first electron transport material,
• wherein the buffer layer is closer to the light emitting layer than is the first charge auxiliary layer.

A quantum dot device, comprising

• a first electrode and a second electrode,
• a light emitting layer between the first electrode and the second electrode, the light emitting layer comprising quantum dots,
• a first charge auxiliary layer between the second electrode and the light emitting layer, the first charge auxiliary layer being an electron auxiliary layer, and
• a buffer layer between the light emitting layer and the first charge auxiliary layer,
• wherein a hole conductivity of the buffer layer is greater than a hole conductivity of the first charge auxiliary layer,
• wherein a hole conductivity of the buffer layer is greater than a conductivity of the light emitting layer, and
• wherein the first electrode is an anode, the second electrode is a cathode, and the buffer layer comprises a hole extraction material.

A quantum dot device, comprising

• a first electrode and a second electrode,
• a light emitting layer between the first electrode and the second electrode, the light emitting layer comprising quantum dots,
• a charge auxiliary layer between the second electrode and the light emitting layer, the charge auxiliary layer comprising an alkali metal compound and metal oxide nanoparticles comprising zinc, and
• a buffer layer between the light emitting layer and the charge auxiliary layer, the buffer layer comprising the metal oxide nanoparticles comprising zinc and a hole extraction material selected from a p-type non-polymer, a p-type polymer, a p-type inorganic material, a p-type organic-inorganic material, or a combination thereof.