Organic photoelectric device and image sensor
An organic photoelectric device includes a first electrode and a second electrode facing each other, and an active layer between the first electrode and the second electrode, wherein the active layer includes an n-type semiconductor compound that is transparent in a visible ray region and represented by Chemical Formula 1, and a p-type semiconductor compound having a maximum absorption wavelength in a wavelength region of about 500 nm to about 600 nm of a visible ray region.
1. An organic photoelectric device comprising:
a first electrode and a second electrode facing each other, and
an active layer between the first electrode and the second electrode,
wherein the active layer includes,
an n-type semiconductor compound that is transparent in a visible ray region and represented by Chemical Formula 1, the n-type semiconductor compound being configured to not substantially absorb visible light in a wavelength region that is greater than or equal to about 400 nm and less than or equal to about 700 nm, and
a p-type semiconductor compound represented by Chemical Formula 3, wherein the p-type semiconductor compound has a maximum absorption wavelength in a wavelength region of about 500 nm to about 600 nm of a visible ray region:
wherein, in Chemical Formula 1,
A is one of a substituted or unsubstituted C6 to C30 aromatic ring group, a substituted or unsubstituted C4 to C30 alicyclic group, a substituted or unsubstituted C3 to C30 hetero aromatic ring group, a substituted or unsubstituted C4 to C30 heteroalicyclic group, and a combination thereof, and
R 1 and R 2 are independently one of a substituted or unsubstituted C6 to C30 aryl group, a substituted or unsubstituted C3 to C30 heteroaryl group, and a combination thereof;
wherein in Chemical Formula 3,
Z is one of S, Se, Te, S(═O), S(═O) 2 , and SiR a R b (wherein R a and R b is hydrogen or a C1 to C10 alkyl group),
Ar 1 and Ar 2 are one of a substituted or unsubstituted C6 to C30 aryl group and a substituted or unsubstituted C4 to C30 heteroaryl group,
R 31 to R 37 are independently one of hydrogen, a substituted or unsubstituted C1 to C30 alkyl group, a substituted or unsubstituted C6 to C30 aryl group, a substituted or unsubstituted C4 to C30 heteroaryl group, a halide group, and a cyano group (CN),
m is an integer ranging from 0 to 4, and
n is 0 or 1.
2. The organic photoelectric device of claim 1 , wherein the n-type semiconductor compound has an energy bandgap that is greater than or equal to about 2.8 eV.
3. The organic photoelectric device of claim 1 , wherein the n-type semiconductor compound has a HOMO level that is greater than about 6.0 eV.
4. The organic photoelectric device of claim 1 , wherein a difference between a HOMO level of the n-type semiconductor compound and a work function of the second electrode is greater than or equal to about 1.5 eV.
5. The organic photoelectric device of claim 1 , wherein the n-type semiconductor compound is represented by one of Chemical Formulae 1a to 1e:
wherein in Chemical Formulae 1a to 1e,
R 3 and R 4 are independently one of a halogen, a C1 to C10 haloalkyl group, a nitro group, a cyano group, a C1 to C10 alkoxy group, and a C1 to C10 alkyl group,
L is one of a C1 to C4 alkylene, a fluoro-substituted C 1 to C4 alkylene, phenylene, S, S(═O), S(═O) 2 , O, and C(═O), and
m and n are independently an integer ranging from 0 to 2.
6. The organic photoelectric device of claim 1 , wherein the p-type semiconductor compound has an energy bandgap that is greater than or equal to about 2.0 eV and less than or equal to about 2.5 eV.
7. The organic photoelectric device of claim 1 , wherein the p-type semiconductor compound has a maximum absorption wavelength (Amax) that is greater than or equal to about 530 nm and less than or equal to about 600 nm.
8. The organic photoelectric device of claim 1 , wherein the active layer is configured to selectively absorb light in a green wavelength region.
9. The organic photoelectric device of claim 1 , wherein a hole blocking layer is not present between the first electrode and the active layer or between the second electrode and the active layer.
10. An image sensor including the organic photoelectric device of claim 1 .
11. The image sensor of claim 10 , wherein the image sensor comprises a semiconductor substrate integrated with a first photo-sensing device configured to sense light in a blue wavelength region and a second photo-sensing device configured to sense light in a red wavelength region, and the organic photoelectric device on the semiconductor substrate is configured to absorb light in a green wavelength region.
12. The image sensor of claim 11 , wherein the first photo-sensing device and the second photo-sensing device are at a different depth from a surface of the semiconductor substrate.
13. The image sensor of claim 11 , wherein the image sensor further comprises a color filter layer on or under the organic photoelectric device.
14. The image sensor of claim 13 , wherein the color filter layer is between the semiconductor substrate and the organic photoelectric device and comprises:
a first color filter corresponding to the first photo-sensing device and configured to selectively transmit light in a blue region, and
a second color filter corresponding to the second photo-sensing device and configured to selectively transmit light in a red region.
15. The organic photoelectric device of claim 1 , wherein the hydrogen of each ring of Chemical Formula A is replaced by a substituent selected from a C1 to C10 linear or branched alkyl group, a halogen, and a cyano group.
16. The organic photoelectric device of claim 1 , wherein R 1 and R 2 are represented by Chemical Formula A:
wherein, in Chemical Formula A,
X a , X b , X c and X d are independently one of O, S, Se, Te, S(═O), S(═O) 2 , and SiR a R b (R a and R b being hydrogen or a C1 to C10 alkyl group).