The compound represented by the following general formula is useful as a material for an organic light emitting device. X.sup.1 and X.sup.2 represent O or S; Y.sup.1 and Y.sup.2 represent a single bond, O, S or C(R.sup.a)(R.sup.b); R.sup.1 to R.sup.22, R.sup.a, and R.sup.b represent H, a deuterium atom, or a substituent, but at least one of R.sup.1 to R.sup.22 is a substituent.

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Embodiments provide a light-emitting device, an electronic apparatus that includes the light-emitting device, and an electronic equipment that includes light-emitting device. The light-emitting device includes a first electrode, a second electrode facing the first electrode, and an interlayer between the first electrode and the second electrode. The interlayer includes an emission layer, a first compound that is a hole-transporting compound, a second compound that is an electron-transporting compound, a third compound including at least one nitrogen atom (N) as a ring-forming atom, and a fourth compound that is a nitrogen-containing compound.

A light-emitting element includes a pair of electrodes, and a light-emitting layer between the pair of electrodes, wherein the light-emitting layer includes a first host material, a second host material, and a first light-emitting material exhibiting thermally activated delayed fluorescence, a concentration of the first host material is greater than a concentration of the second host material in the light-emitting layer, a band gap of the first host material is larger than a band gap of the second host material, a singlet excitation energy level of the first light-emitting material is lower than a singlet excitation energy level of the first host material, and a triplet excitation energy level of the second host material is lower than a triplet excitation energy level of the first host material.

A light conversion layer includes a conversion material. The conversion material includes an up-conversion luminescent material and/or a down-conversion luminescent material. The light conversion layer is arranged on a light incident side of a light absorption layer of the solar cell. By introducing the light conversion layer including the up-conversion luminescent material and/or the down-conversion luminescent material into the solar cell, long-wavelength band (low energy) and/or short-wavelength band (high energy) photons can be absorbed and converted into wavebands that can be absorbed by the light absorption layer.

An organic light-emitting diode is provided. The organic light-emitting diode includes an anode, a cathode, and a light-emitting layer disposed therebetween. The cathode includes a ferromagnetic metal layer that selectively conducts spin-polarized electrons. An electron-conduction layer is disposed between the cathode and the light-emitting layer. A spin-polarizing hole-transport layer that supplies spin-polarized holes to the light-emitting layer is disposed between the anode and the light-emitting layer. The spin-polarized electrons and the spin-polarized holes recombine within the light-emitting layer.