White light organic light-emitting diode (WOLED) devices and preparation methods thereof, WOLED display apparatuses

A preparation method of a white light organic light-emitting diode (WOLED) device, comprising:

• forming a red-fluorescence emitting layer on a side of an anode by a first evaporation;
• forming a green-fluorescence emitting layer on a side of the red-fluorescence emitting layer away from the anode by a second evaporation;
• forming an interlayer on a side of the green-fluorescence emitting layer away from the anode by a third evaporation, wherein the interlayer comprises a first Host material and a first TADF material;
• forming a blue-fluorescence emitting layer on a side of the interlayer away from the anode by a fourth evaporation;
• and
• forming a cathode on a side of the blue-fluorescence emitting layer away from the anode by a fifth evaporation;
• wherein
• emission spectra of the WOLED device comprise a first peak which is a main peak, wherein a peak wavelength of the first peak is not greater than 485 nm;
• the emission spectra of the WOLED device comprise a second peak in green-band, wherein a peak wavelength of the second peak is in a range of 510 nm˜525 nm;
• the emission spectra of the WOLED device comprise a third peak and a fourth peak in red-band, wherein a peak wavelength of the third peak is in a range of 610 nm˜625 nm, and a peak wavelength of the fourth peak is in a range of 656 nm˜670 nm;
• and
• magnitudes of the first peak, the second peak, the third peak and the fourth peak are descending.