CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to and the benefit of Korean Patent Application No. 10-2019-0075908, filed in the Korean Intellectual Property Office on Jun. 25, 2019, the entire contents of which are incorporated herein by reference.

BACKGROUND

1. Field

Example embodiments provide a compound and a photoelectric device, an image sensor, and an electronic device including the same.

2. Description of the Related Art

A photoelectric device converts light into an electrical signal using photoelectric effects. The photoelectric device may include a photodiode, a phototransistor, and the like, and it may be applied to an image sensor, an organic light emitting diode, and the like.

An image sensor including a photodiode requires high resolution and thus a small pixel. At present, a silicon photodiode is widely used, but it has a problem of deteriorated sensitivity since silicon photodiode has a smaller absorption area due to small pixels. Accordingly, an organic material that is capable of replacing silicon has been researched.

The organic material has a high absorption coefficient and selectively absorbs light in a particular wavelength region depending on a molecular structure, and thus may simultaneously replace a photodiode and a color filter and resultantly improve sensitivity and contribute to high integration.

SUMMARY

Example embodiments provide a compound capable of selectively absorbing light in a green wavelength region and having improved thermal stability.

Example embodiments also provide a photoelectric device (e.g., organic photoelectric device) capable of selectively absorbing light in the green wavelength region and maintaining good efficiency even under high temperature conditions.

Example embodiments also provide an image sensor including the photoelectric device (e.g., organic photoelectric device).

Example embodiments also provide an electronic device including the image sensor.

According to example embodiments, a compound is represented by Chemical Formula 1.



In Chemical Formula 1,

Ar is a substituted or unsubstituted C6 to C30 hydrocarbon cyclic group a substituted or unsubstituted C2 to C30 heterocyclic group or a fused ring thereof,

Ar has at least one functional group selected from C═O, C═S, C═Se, and C═Te,

X is O, S, Se, Te, S(═O), S(═O)2, SiRaRb, GeRcRd, or CReRf(wherein Ra, Rb, Rc, Rd, Re, and Rfare independently hydrogen or a substituted or unsubstituted C1 to C10 alkyl group, and wherein Ra, Rb, Rc, Rd, Re, and Rfare independently present and Raand Rb, Rcand Rd, or Reand Rfare linked to each other to provide a spiro structure),

Y1and Y2are independently O, S, Se, or Te, and

R1to R4are independently hydrogen, deuterium, a substituted or unsubstituted C1 to C30 alkyl group, a substituted or unsubstituted C1 to C30 alkoxy group, a substituted or unsubstituted C6 to C30 aryl group, a substituted or unsubstituted C3 to C30 heteroaryl group, a substituted or unsubstituted C2 to C30 acyl group, a halogen, a cyano group (—CN), a cyano-containing group, a nitro group, a pentafluorosulfanyl group (—SF5), a hydroxyl group, a hydrazine group, a hydrazone group, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, —SiRaRbRc(wherein Ra, Rb, and Rcare independently hydrogen or a substituted or unsubstituted C1 to C10 alkyl group), or a combination thereof, or

adjacent two groups of R1to R4are linked to each other to provide a substituted or unsubstituted C5 to C30 hydrocarbon cyclic group or a substituted or unsubstituted C2 to C30 heterocyclic group. In Chemical Formula 1, Y1and Y2may be the same or different. In addition, X may be the same as or different from Y1and Y2.

In some embodiments, in Chemical Formula 1, X may be one of S, Se, and Te and Y1and Y2independently may be one of S, Se, and Te. In Chemical Formula 1, X may be one of SiRaRb, GeRcRd, and CReRfand Y1and Y2independently may be one of O, S, Se, and Te.

In some embodiments, in Chemical Formula 1, Ar may be a cyclic group represented by Chemical Formula 3.



In Chemical Formula 3,

Ar′ is a substituted or unsubstituted C6 to C30 aryl group or a substituted or unsubstituted C3 to C30 heteroaryl group,

Z1is O, S, Se, or Te, and

Z2is O, S, Se, Te, or CRaRb, wherein Raand Rbare independently hydrogen, a substituted or unsubstituted C1 to C10 alkyl group, a cyano group, or a cyano-containing group, provided that when Z2is CRaRb, at least one of Raand Rbis a cyano group or a cyano-containing group.

In some embodiments, in Chemical Formula 1, Ar may be a cyclic group represented by one of Chemical Formulae 4A to 4F.



In Chemical Formula 4A,

Z1is O, S, Se, or Te,

Z2is O, S, Se, Te, or CRaRb, wherein Raand Rbare independently hydrogen, a substituted or unsubstituted C1 to C10 alkyl group, a cyano group, or a cyano-containing group, provided that when Z2is CRaRb, at least one of Raand Rbis a cyano group or a cyano-containing group,

Z3is N or CRc(wherein Rcis hydrogen, deuterium, or a substituted or unsubstituted C1 to C10 alkyl group),

R11, R12, R13, R14, and R15are the same or different and are independently hydrogen, deuterium, 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 halogen, a cyano group (—CN), a cyano-containing group, or a combination thereof, wherein R11, R12, R13, R14, and R15are independently present or at least one of R12and R13and R14and R15is linked with each other to provide a fused aromatic ring,

n is 0 or 1, and

* is a linking position.



In Chemical Formula 4B,

Z1is O, S, Se, or Te,

Z2is O, S, Se, Te, or CRaRb, wherein Raand Rbare independently hydrogen, a substituted or unsubstituted C1 to C10 alkyl group, a cyano group, or a cyano-containing group, provided that when Z2is CRaRb, at least one of Raand Rbis a cyano group or a cyano-containing group,

Y1is O, S, Se, Te, or C(Ra)(CN) (wherein Rais hydrogen, a cyano group (—CN), or a C1 to C10 alkyl group),

R11and R12are independently hydrogen, deuterium, a substituted or unsubstituted C1 to C30 alkyl group, a substituted or unsubstituted C1 to C30 alkoxy group, a substituted or unsubstituted C6 to C30 aryl group, a substituted or unsubstituted C4 to C30 heteroaryl group, a halogen, a cyano group (—CN), or a combination thereof, and

* is a linking position.



In Chemical Formula 4C,

Z1is O, S, Se, or Te,

Z2is O, S, Se, Te, or CRaRb, wherein Raand Rbare independently hydrogen, a substituted or unsubstituted C1 to C10 alkyl group, a cyano group, or a cyano-containing group, provided that when Z2is CRaRb, at least one of Raand Rbis a cyano group or a cyano-containing group,

R11, R12, and R13are the same or different and are independently hydrogen, deuterium, a substituted or unsubstituted C1 to C30 alkyl group, a substituted or unsubstituted C1 to C30 alkoxy group, a substituted or unsubstituted C6 to C30 aryl group, a substituted or unsubstituted C4 to C30 heteroaryl group, a halogen, a cyano group, a cyano-containing group, or a combination thereof, and

* is a linking position.



In Chemical Formula 4D,

Z1is O, S, Se, or Te,

Z2is O, S, Se, Te, or CRaRb, wherein Raand Rbare independently hydrogen, a substituted or unsubstituted C1 to C10 alkyl group, a cyano group, or a cyano-containing group, provided that when Z2is CRaRb, at least one of Raand Rbis a cyano group or a cyano-containing group,

Z3is N or CRc(wherein Rcis hydrogen or a substituted or unsubstituted C1 to C10 alkyl group),

G1is O, S, Se, Te, SiRxRy, or GeRzRw, wherein Rx, Ry, Rz, and Rware the same or different and are independently hydrogen, a halogen, a substituted or unsubstituted C1 to C10 alkyl group, or a substituted or unsubstituted C6 to C10 aryl group,

R11, R12, and R13are the same or different and are independently hydrogen, deuterium, a substituted or unsubstituted C1 to C30 alkyl group, a substituted or unsubstituted C1 to C30 alkoxy group, a substituted or unsubstituted C6 to C30 aryl group, a substituted or unsubstituted C4 to C30 heteroaryl group, a halogen, a cyano group, a cyano-containing group, or a combination thereof, wherein R12and R13are independently different and are linked with each other to provide a fused aromatic ring,

n is 0 or 1, and

* is a linking position.



In Chemical Formula 4E,

Z1is O, S, Se, or Te,

Z2is O, S, Se, Te, or CRaRb, wherein Raand Rbare independently hydrogen, a substituted or unsubstituted C1 to C10 alkyl group, a cyano group, or a cyano-containing group, provided that when Z2is CRaRb, at least one of Raand Rbis a cyano group or a cyano-containing group,

Z4is N or CRc(wherein Rcis hydrogen or a substituted or unsubstituted C1 to C10 alkyl group),

G2is O, S, Se, Te, SiRxRy, or GeRzRw, wherein Rx, Ry, Rz, and Rware the same or different and are independently hydrogen, a halogen, a substituted or unsubstituted C1 to C10 alkyl group, or a substituted or unsubstituted C6 to C10 aryl group,

R11, R12, and R13are the same or different and are independently hydrogen, deuterium, a substituted or unsubstituted C1 to C30 alkyl group, a substituted or unsubstituted C1 to C30 alkoxy group, a substituted or unsubstituted C6 to C30 aryl group, a substituted or unsubstituted C4 to C30 heteroaryl group, a halogen, a cyano group, a cyano-containing group, or a combination thereof,

n is 0 or 1, and

* is a linking position.



In Chemical Formula 4F,

Z1is O, S, Se, or Te,

Z2is O, S, Se, Te, or CRaRb, wherein Raand Rbare independently hydrogen, a substituted or unsubstituted C1 to C10 alkyl group, a cyano group, or a cyano-containing group, provided that when Z2is CRaRb, at least one of Raand Rbis a cyano group or a cyano-containing group,

R11is hydrogen, deuterium, 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 halogen, a cyano group (—CN), a cyano-containing group, or a combination thereof, and

G3is O, S, Se, Te, SiRxRy, or GeRzRw, wherein Rx, Ry, Rz, and Rware the same or different and are independently hydrogen, a halogen, a substituted or unsubstituted C1 to C10 alkyl group, or a substituted or unsubstituted C6 to C10 aryl group.

In some embodiments, the compound represented by Chemical Formula 1 may have an aspect ratio (Z/X) of less than or equal to about 0.30. The aspect ratio may be obtained by dividing a shortest length (Z) of the compound by a longest length (X) of the compound.

In some embodiments, the compound may have a maximum absorption wavelength (λmax) in a wavelength range of greater than or equal to about 500 nm and less than or equal to about 580 nm, for example greater than or equal to about 520 nm and less than or equal to about 555 nm in a thin film state.

In some embodiments, the compound may exhibit a light absorption curve having a full width at half maximum (FWHM) of about 50 nm to about 120 nm.

In some embodiments, a difference between a melting point of the compound and a temperature at which 10 wt % of an initial weight is lost (deposition temperature) may be greater than or equal to about 10° C.

According to another embodiment, a photoelectric device (e.g., organic photoelectric device) includes a first electrode and a second electrode facing each other and an active layer interposed between the first electrode and the second electrode, wherein the active layer includes the compound represented by Chemical Formula 1.

According to another embodiment, an image sensor includes the photoelectric device.

In some embodiments, the image sensor may include a semiconductor substrate integrated with a plurality of first photo-sensing devices configured to sense light in a blue wavelength region and a plurality of second photo-sensing devices configured to sense light in a red wavelength region, and the photoelectric device may be on the semiconductor substrate and configured to sense light in a green wavelength region.

In some embodiments, the image sensor may further include a color filter layer comprising a blue filter configured to selectively transmit light in a blue wavelength region and a red filter configured to selectively transmit light in a red wavelength region.

In some embodiments, the first photo-sensing device and the second photo-sensing device may be stacked in a vertical direction in the semiconductor substrate.

In some embodiments, the image sensor may include a green photoelectric device which is the photoelectric device, a blue photoelectric device configured to selectively absorb light in a blue wavelength region, and a red photoelectric device configured to selectively absorb light in a red wavelength region. The blue photoelectric device and the red photoelectric device may be stacked.

According to another embodiment, an electronic device includes the image sensor.

The compound may selectively absorb light in a green wavelength region and may have thermal stability and charge mobility. The compound improves efficiency of the device by increasing wavelength selectivity of the green wavelength region and provides photoelectric devices, image sensors and electronic devices that do not deteriorate performance even at high temperature processes due to improved thermal stability.

