Organic light-emitting device and electronic apparatus including the same

An organic light-emitting device comprising:

• a first electrode;
• a second electrode;
• and
• an organic layer positioned between the first electrode and the second electrode,
• wherein the organic layer comprises an emission layer,
• wherein the emission layer comprises a first compound and a second compound,
• wherein the first compound and the second compound are each independently a multiresonance thermally activated delayed fluorescence material, and
• wherein the first compound and the second compound satisfy Inequality 1:
• 5.
• ×
• 10
• 1
• ⁢
• 4
• ⁢
• M
• -
• 1
• ⁢
• cm
• -
• 1
• ⁢
• nm
• 4
• ≤
• SOI
• M
• ⁢
• R
• ⁢
• 1
• -
• M
• ⁢
• R
• ⁢
• 2
• ≤
• 5.
• ×
• 10
• 1
• ⁢
• 5
• ⁢
• M
• -
• 1
• ⁢
• cm
• -
• 1
• ⁢
• nm
• 4
• Inequality
• ⁢
• 1
• wherein, in Inequality 1,
• SOIMR1-MR2 is a spectral overlap integral (J) of a photoluminescence spectrum of the first compound and an ultraviolet absorption spectrum of the second compound, and
• the spectral overlap integral is evaluated by Expression 1:
• J
• =
• ∫
• f
• D
• (
• λ
• )
• ⁢
• ϵ
• A
• (
• λ
• )
• ⁢
• λ
• 4
• ⁢
• d
• ⁢
• λ
• ∫
• f
• D
• (
• λ
• )
• ⁢
• d
• ⁢
• λ
• =
• ∫
• f
• D
• _
• (
• λ
• )
• ⁢
• ϵ
• A
• (
• λ
• )
• ⁢
• λ
• 4
• ⁢
• d
• ⁢
• λ
• Expression
• ⁢
• 1
• wherein, in Expression 1,
• J is the spectral overlap integral, in units of M−1cm−1nm4, of the photoluminescence spectrum of the first compound and an ultraviolet absorption spectrum of the second compound,
• ϵA(λ) is a molar extinction coefficient of the second compound calculated from the absorption spectrum of the second compound,
• λ is a wavelength of the photoluminescence spectrum and the absorption spectrum in units of nm,
• fD(λ) is the photoluminescence spectrum of the first compound normalized to an area 1.