Wavelength-conversion encapsulant composition, wavelength-converted encapsulant layer, and solar cell module using same
A wavelength-converting encapsulant composition is provided, which includes a first organic material capable of absorbing ultraviolet light and converting absorbed light to longer wavelength light; and a second organic material capable of absorbing light with a wavelength longer than that of the light absorbed by the first organic material and converting absorbed light to longer wavelength light, wherein the maximum emission wavelength λ 1em of the first organic material and the maximum excitation wavelength λ 2ex of the second organic material satisfy the relationship of formula (1): λ 1em −60≤λ 2ex (nm), and which has high durability, is advantageous in terms of cost and suitable for use on solar cells, and can improve the photoelectric conversion efficiency of solar cells by converting light in a wavelength region not contributable to power generation to light in another wavelength region contributable to power generation.
1. A wavelength-converting encapsulant composition, comprising:
a first organic material capable of absorbing ultraviolet light and converting absorbed light to light with a wavelength longer than that of the absorbed light; and
a second organic material capable of absorbing light with a wavelength longer than that of the light absorbed by the first organic material and converting absorbed light to light with a wavelength longer than that of the absorbed light,
wherein:
the first organic material has a maximum absorption wavelength λ 1abs and a maximum emission wavelength λ 1em ;
the second organic material has a maximum excitation wavelength λ 2ex of 450 nm or less;
the maximum emission wavelength λ 1em of the first organic material and the maximum excitation wavelength λ 2ex of the second organic material satisfy the relationship of formula (1): λ 1em −60≤λ 2ex (nm);
the maximum absorption wavelength λ 1abs of the first organic material and the maximum excitation wavelength λ 2ex of the second organic material satisfy the relationship of formula (2): λ 2ex −λ 1abs ≥5 (nm); and
the first organic material has an emission quantum yield ϕ 1 of 85% or more.
2. The wavelength-converting encapsulant composition according to claim 1 , wherein the first organic material has a Stokes shift Δλ 1 of 50 nm or more.
3. The wavelength-converting encapsulant composition according to claim 1 , wherein the second organic material has an emission quantum yield ϕ 2 of 85% or more.
4. The wavelength-converting encapsulant composition according to claim 1 , wherein the first organic material comprises at least one selected from the group consisting of a perylene derivative, a benzoxazole derivative, a benzothiadiazole derivative, a benzotriazole derivative, and a fluorene derivative.
5. The wavelength-converting encapsulant composition according to claim 1 , wherein the second organic material comprises at least one selected from the group consisting of a perylene derivative, a benzoxazole derivative, a benzothiadiazole derivative, a benzotriazole derivative, and a fluorene derivative.
6. The wavelength-converting encapsulant composition according to claim 1 , which is for use in solar cell applications.
7. A wavelength-converting encapsulant layer comprising a product made from the wavelength-converting encapsulant composition according to claim 1 .
8. A solar cell module comprising the wavelength-converting encapsulant layer according to claim 7 and a solar cell.
9. The solar cell module according to claim 8 , wherein the solar cell is a crystalline silicon solar cell, an amorphous silicon solar cell, a microcrystalline silicon solar cell, a thin-film silicon solar cell, a heterojunction solar cell, a multi-junction solar cell, a cadmium sulfide/cadmium telluride solar cell, a CIS thin-film solar cell, a CIGS thin-film solar cell, a CZTS thin-film solar cell, a group III-V solar cell, a dye-sensitized solar cell, or an organic semiconductor solar cell.