The present disclosure provides an organic electroluminescent device and a display panel. The organic electroluminescent device provided by the present disclosure includes: a first electrode, a second electrode and a light-emitting layer located between the first electrode and the second electrode, and an optical structure located at a side of the first electrode facing away from the light-emitting layer. A reflectance of the optical structure with respect to light of a specific wavelength band is greater than a reflectance of the optical structure with respect to light of a wavelength band other than the specific wavelength band, the light of the specific wavelength band being light emitted by the organic electroluminescent device, and a material for forming the optical structure includes at least one of nitrogen, oxygen, and fluorine.