KR102275209B1 - photosensitive film composition for photosensor, photosensor comprising the same, and preparation method thereof - Google Patents

Abstract

A photosensitive layer composition for a photosensor according to an embodiment of the present invention includes a first photosensitive material including a compound represented by a chemical formula 1; and a light signal amplification/noise suppressor containing a bifullerene compound. In the chemical formula 1, n is a natural number. The optical signal amplification/noise suppressor can effectively separate charges formed by optical signals and suppress the flow of charges in a reverse direction.

Description

A photosensitive layer composition for a photosensor, a photosensor comprising the same, and a manufacturing method thereof

The present invention relates to a photosensitive layer composition for a photosensor comprising an optical signal amplification/noise suppressor and a photosensitive material having a controllable energy level, a photosensor comprising the same, and a method for manufacturing the same.

An optical sensor is a semiconductor device that detects and senses optical energy and converts it into an electrical signal, and is distinguished from a photovoltaic cell that directly converts and produces optical energy into electrical energy. Optical sensors are semiconductor devices applied to semiconductor-based sensor fields such as photodetectors, image sensors, chemical detection sensors, and medical sensors.

Since the photosensitive layer of the photosensor plays a role in sensing light, the ratio of the photocurrent generated by light to the dark current in the absence of light is very important. In particular, since the photosensor operates in a state in which a reverse bias is applied, a device for suppressing the injected charge in the dark state is absolutely required.

Therefore, it is optimized for the sensing role of the photosensor, and while it is possible to increase the ratio of photocurrent to dark current in the photosensor, it is necessary to develop a photosensitive layer composition to improve photosensitivity and stability due to external stimuli such as heat or light. . However, research on only the composition of a photovoltaic cell such as a solar cell has been actively conducted, and research on a photosensitive layer material for a photosensor optimized for a photosensor is insufficient.

Korean Patent Publication KR 10-2019-0003677 A

The present invention relates to a photosensitive layer composition optimized for a thin film type organic photosensor, and to provide an optical signal amplification/noise suppressor capable of effectively separating charges formed by optical signals and suppressing the flow of charges in the reverse direction do. Another object of the present invention is to provide a photosensitive material capable of maximizing the performance of the photosensor in terms of energy level by being mixed therewith.

In order to achieve the above object,

A photosensitive layer composition for a photosensor according to an embodiment of the present invention includes a first photosensitive material including a compound represented by the following Chemical Formula 1; and an optical signal amplification/noise suppressor comprising a bifullerene compound.

[Formula 1]

(in Formula 1, n is a natural number).

In addition, in the photosensitive layer composition for a photosensor according to an embodiment of the present invention, the non-fullerene compound may be a compound represented by the following formula (2).

[Formula 2]

(In Formula 2, R1, R2, R3 and R4 are the same or different from each other, C1 to C20 alkyl group, alkenyl group, alkynyl group)

In addition, as an embodiment, the weight ratio of the optical signal amplification/noise suppressor including the first photosensitive material and the non-fullerene compound of the photosensitive layer composition for a photosensor according to an embodiment of the present invention is 1: 4 to 4 : can be 1.

In addition, the photosensitive layer composition for a photosensor according to an embodiment of the present invention includes an optical signal amplification/noise suppressor comprising the bifullerene compound represented by Formula 2 above.

In addition, as an embodiment, the photosensitive layer composition for the photosensor is PBDB-T (poly[(2,6-(4,8-bis(5-(2-ethylhexyl)thiophen-2-yl)-benzo[ 1,2-b:4,5-b']dithiophene))-alt-(5,5-(1',3'-di-2-thienyl-5',7'-bis(2-ethylhexyl)benzo [1',2'-c:4',5'-c']dithiophene-4,8-dione))), PCDTBT (Poly[N-9'-heptadecanyl-2,7-carbazole-alt-5 ,5-(4′,7′-di-2-thienyl-2′,1′,3′-benzothiadiazole)], PTB-7 (Poly[[4,8-bis[(2-ethylhexyl)oxy]benzo [1,2-b:4,5-b']dithiophene-2,6-diyl][3-fluoro-2-[(2-ethylhexyl)carbonyl]thieno[3,4-b]thiophenediyl]] and PTB7 -Th(Poly[4,8-bis(5-(2-ethylhexyl)thiophen-2-yl)benzo[1,2-b;4,5-b']dithiophene-2,6-diyl-alt-( At least one of 4-(2-ethylhexyl)-3-fluorothieno[3,4-b]thiophene-)-2-carboxylate-2-6-diyl)] may further include a second photosensitive material.

In addition, as an embodiment, the weight ratio of the optical signal amplification/noise suppressor including the second photosensitive material and the bifullerene compound represented by Formula 2 in the photosensitive layer composition for an optical sensor according to an embodiment of the present invention It may be 1: 4 to 4: 1.

In addition, as an embodiment, the photosensitive layer composition for a photosensor according to an embodiment of the present invention is 1,8-diiodooctane (DIO:1,8-diiodooctane), 1-chloronaphthalene (1-CN:1) -chloronaphthalene), diphenyl ether (DPE:diphenylether), octane dithiol (octane dithiol), and tetrabromothiophene (tetrabromothiophene) at least one or more additives selected from the may be further included.

In addition, the photosensor according to an embodiment of the present invention includes a first electrode; a second electrode provided to face the first electrode; a blocking layer provided between the first electrode and the second electrode; and a photosensitive layer including the photosensitive layer composition for the photosensor provided between the blocking layer and the first electrode or between the blocking layer and the second electrode.

Also, as an embodiment, the photosensor according to an embodiment of the present invention may include one blocking layer, and the one blocking layer may be an electron blocking layer (EBL). .

Also, as an embodiment, in the photosensor according to an embodiment of the present invention, the blocking layer may include PEDOT:PSS (poly(3,4-ethylenediocy-thiophene) doped with poly(styrenesulfonic acid)).

Also, as an embodiment, in the photosensor according to an embodiment of the present invention, the first electrode may be indium-containing tin oxide, aluminum-containing zinc oxide, indium-containing zinc oxide, or a mixture thereof.

In addition, as an embodiment, in the photosensor according to an embodiment of the present invention, the second electrode is gold (Au), silver (Ag), platinum (Pt), palladium (Pd), copper (Cu), aluminum (Al) ), carbon (C), cobalt sulfide (CoS), copper sulfide (CuS), nickel oxide (NiO), or a mixture thereof.

In addition, the optical sensor manufacturing method according to an embodiment of the present invention comprises the steps of ultrasonically processing the first electrode substrate; applying a barrier layer composition on the sonicated first electrode substrate; heat-treating the first electrode substrate to which the barrier layer composition is applied; applying a photosensitive layer composition on the blocking layer; and applying a second electrode on the applied photosensitive layer.

In addition, as an embodiment, in the optical sensor manufacturing method according to an embodiment of the present invention, after the step of ultrasonicating the first electrode substrate and before the step of applying the blocking layer composition on the first electrode substrate, the ultrasonic treatment is performed. The method may further include oxidizing the surface of the first electrode substrate.

The photosensitive layer composition for a photosensor according to an embodiment of the present invention effectively separates charges formed by an optical signal and suppresses a dark current (noise). In addition, the composition can serve as a hole blocking agent together, thereby suppressing excellent photosensitivity and reverse charge flow with only one blocking layer. In addition, the optical sensor including the composition has excellent light absorption ability and improved stability against external stress.

1 illustrates an organic photosensor structure to which a photosensitive layer composition according to an embodiment of the present invention is applied.
2 is a comparison of the driving mechanism of an organic photosensor to which fullerene (a) and non-fullerene (b) optical signal amplification/noise suppressors are applied.
3 is a graph comparing dark current (a) and external quantum efficiency (b) characteristics of an organic photosensor to which a photosensitive layer composition according to Comparative Examples and Examples of the present invention is applied.
4 is a graph comparing the performance index (a) and the linear dynamic region (b) of the organic photosensor to which the photosensitive layer composition according to Comparative Examples and Examples of the present invention is applied.
5 is a graph comparing response speed characteristics (c)/(d) of an organic photosensor to which a photosensitive layer composition according to a comparative example and an embodiment of the present invention is applied.
6 is a graph comparing thermal stability (a)/(b) and electrical stability (c)/(d) of an organic photosensor to which a photosensitive layer composition according to Comparative Examples and Examples of the present invention is applied.
7 is a graph comparing the photosensitivity of the organic photosensor to which the photosensitive layer composition according to Comparative Examples and Examples of the present invention is applied.

Hereinafter, the present invention will be described in more detail through examples. These examples are only for illustrating the present invention, and therefore, the scope of the present invention should not be construed as being limited by these examples.

As used herein, an expression such as "comprising" is understood as an open-ended term that includes the possibility of including other embodiments, unless specifically stated otherwise in the phrase or sentence in which the expression is included. should be

As used herein, “preferred” and “preferably” refer to embodiments of the invention that may provide certain advantages under certain circumstances. However, other embodiments may also be preferred, under the same or other circumstances. Additionally, the recitation of one or more preferred embodiments does not imply that other embodiments are not useful, nor is it intended to exclude other embodiments from the scope of the invention.

Each step may occur in a different order than the stated order unless the context clearly dictates a specific order. That is, each step may occur in the same order as specified, may be performed substantially simultaneously, or may be performed in the reverse order.

In the present specification, when a member is said to be positioned 'on' another member, this includes not only a case in which a member is in contact with another member but also a case in which another member is present between the two members.

Since the photosensitive layer in the photosensor plays a major role in sensing light, the higher the ratio of the photocurrent generated by light to the dark current in the absence of light, the higher the performance. In particular, the dark current is more important than the photocurrent do. In addition, since the photosensor operates in a state in which a reverse bias is applied, a device for suppressing the injected charge in the dark state is absolutely required.

Since the dark current in the photosensor is closely related to the trap density in the photosensitive layer and the lowest unoccupied molecular orbital (LUMO) energy level of the optical signal amplification/noise suppressor, lower the trap density and lower the LUMO level to -4.5 eV or higher (- 3.8 eV, etc.) is important. Through this, minimizing the dark current by suppressing the charge injected in the dark state helps to improve the performance of the photosensor.

Accordingly, the present invention is optimized for a photosensor, and provides the following photosensitive layer composition for a photosensor capable of amplifying an optical signal and suppressing a dark current, which is as follows.

A photosensitive layer composition for a photosensor according to an embodiment of the present invention includes a first photosensitive material including a compound represented by the following Chemical Formula 1; and an optical signal amplification/noise suppressor comprising a bifullerene compound.

[Formula 1]

(in Formula 1, n is a natural number)

The photosensor is a device that detects an object using light, and may include a photodetector, a phototransistor, an image sensor, and a semiconductor device applied to the optical sensor field. In particular, as an embodiment, the effect of using the photosensitive layer composition including the optical signal amplification/noise suppressor including the first photosensitive material and the non-fullerene compound in the photodetector will be described below.

The photosensitive layer composition of the present invention includes an optical signal amplifying/noise suppressing group including a non-fullerene compound, thereby improving the photosensitivity of the photosensor compared to the case where the fullerene derivative is used as an optical signal amplifying/noise suppressing group. When the non-fullerene derivative is applied to an optical sensor, the power conversion efficiency is excellent, and the molecular design and electron affinity are easier to adjust than the fullerene derivative. In addition, when the non-fullerene compound is applied to the photosensor, it is stable to external stimuli and the charge mobility can be maintained over time.

2 shows the principle of operation of a fullerene compound and a non-fullerene compound in a photosensor device under dark conditions. When the fullerene compound is used as an optical signal amplification/noise suppressor (a), holes are injected into the HOMO of the photosensitive material at the cathode, and the LUMO of the optical signal amplification/noise suppressor at the anode under reverse bias Electrons are injected into (LUMO) to induce a dark current. On the other hand, in the case of the non-fullerene compound (b), since it has a lower LUMO level than the fullerene compound, the electron barrier (Δ Φ ) is increased. Therefore, when the non-fullerene compound is used as an optical signal amplification/noise suppressor, there is an effect of lowering the dark current.

In one embodiment, the bifullerene compound is IDTBR, o-IDTBR, eh-IDTBR, IDFBR, ITIC, ITIC-2F, ITIC-4F, ITIC-M, ITIC-Th, IEICO, IEICO-4F, IEICO-4Cl, It may be at least one selected from IDIC, IFBR, ITCC, and IEIC, but is not particularly limited thereto.

As a more preferred embodiment, the photosensitive layer composition for a photosensor of the present invention may include a compound represented by the following Chemical Formula 2 among non-fullerene compounds as an optical signal amplification/noise suppressor.

[Formula 2]

(in Formula 1, n is a natural number).

As a more preferred embodiment, the photosensitive layer composition for an optical sensor of the present invention may include a non-fullerene compound represented by the following Chemical Formula 3 among non-fullerene compounds as an optical signal amplification/noise suppressor.

[Formula 3]

In addition, the optical signal amplification/noise suppressor composition including the compound represented by Formula 2 or 3 has an isotropic crystal structure suitable for inducing charge transfer to generate a photocurrent in the photosensor. In addition, the optical signal amplification/noise suppressor material may act as a sensitizer for signal enhancement in the optical sensor and simultaneously act as a suppressor of dark current. That is, since a relatively high electron barrier is formed in terms of energy level, the dark current can be further suppressed, which increases the photosensitivity.

In addition, the bifullerene compound serves as a hole blocking agent in the photosensor. Therefore, when the non-fullerene compound is used as a composition, thermal stability and a fast response effect to light can be realized without a separate hole blocking layer.

In particular, as an embodiment, the effect of using the optical signal amplification/noise suppressor composition including the compound represented by Formula 2 or 3 in the photodetector will be described below.

In addition, the photosensitive layer composition of the present invention is combined with the optical signal amplification/noise suppressor including the non-fullerene compound as a pair to maximize the light detection ability of the photosensor. include

In the case of the first photosensitive material, since it has a relatively low band gap energy, the photoelectric conversion efficiency is high, and thus has been widely used in the photovoltaic field. However, in terms of application of the optical sensor, there are several problems, so there are not many prior studies, and the performance has been shown to be inferior compared to other materials. The problem is: First, the dark current is relatively high because the charge injection probability is relatively high compared to other materials (P3HT, PCDTBT, etc.) on the highest occupied molecular orbital (HOMO) level. Second, the stability of the amorphous polymer is relatively low due to the phenomenon of self-aggregation by heat or external force.

Accordingly, it was confirmed that the present invention showed optimal performance and stability by mixing non-fullerene materials designed to improve the above problems.

The first photosensitive material of Formula 1 has excellent external quantum and has an energy level capable of improving the responsiveness of the organic sensing material in combination with the optical signal amplification/noise suppressor. In addition, since the optical signal amplification/noise suppressor including the compound represented by Formula 2 as a non-fullerene compound is effectively packed by the first photosensitive material including the compound represented by Formula 1, heat and bias stress It is not easily deteriorated by bias stress. In addition, since electrons are rapidly extracted from the first photosensitive material of Formula 1 to the optical signal amplification/noise suppressor, the photosensor has a faster response speed.

In a more preferred embodiment, the weight ratio of the optical signal amplification/noise suppressor including the first photosensitive material and the non-fullerene compound may be 1: 4 to 4: 1, more preferably 2: 3 to 3: 2 have. When the above weight ratio is satisfied, the morphology and molecular arrangement of the photosensitive material and the optical signal amplification/noise suppressor are properly formed, thereby increasing the photosensitivity.

In addition, the photosensitive layer composition for a photosensor according to an embodiment of the present invention includes an optical signal amplification/noise suppressor comprising the compound represented by Formula 2 above.

In addition, PBDB-T(poly[(2,6-(4,8-bis(5-(2-ethylhexyl)thiophen-2-yl)-benzo[1,2-b:4,5-b']dithiophene) ))-alt-(5,5-(1',3'-di-2-thienyl-5',7'-bis(2-ethylhexyl)benzo[1',2'-c:4',5' -c']dithiophene-4,8-dione)))), PCDTBT (Poly[N-9'-heptadecanyl-2,7-carbazole-alt-5,5-(4',7'-di-2- thienyl-2′,1′,3′-benzothiadiazole)], PTB-7 (Poly[[4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b′] dithiophene-2,6-diyl][3-fluoro-2-[(2-ethylhexyl)carbonyl]thieno[3,4-b]thiophenediyl]] and PTB7-Th(Poly[4,8-bis(5-( 2-ethylhexyl)thiophen-2-yl)benzo[1,2-b;4,5-b']dithiophene-2,6-diyl-alt-(4-(2-ethylhexyl)-3-fluorothieno[3, 4-b]thiophene-)-2-carboxylate-2-6-diyl)] at least one second photosensitive material may be further included, but the compound is not particularly limited.

The optical signal amplification/noise suppressor including the compound represented by Formula 2 or Formula 3 has an isotropic crystal structure suitable for inducing charge transfer to generate a photocurrent in the photosensor. In addition, since the optical signal amplification/noise suppressor material forms a relatively high electron barrier in terms of energy level, it is possible to further suppress the dark current.

In addition, the bifullerene compound serves as a hole blocking agent in the photosensor. Since the compound effectively suppresses dark current by forming a high electron barrier, noise can be suppressed without an additional hole blocking layer. Therefore, when the non-fullerene compound is used as an optical signal amplification/noise suppressor, thermal stability and a fast response effect to light can be realized without installing a separate hole blocking layer.

In a more preferred embodiment, the weight ratio of the second photosensitive material and the optical signal amplification/noise suppressor may be 1:4 to 4:1, more preferably 2:3 to 3:2. When the above weight ratio is satisfied, the morphology and molecular arrangement of the photosensitive material and the optical signal amplification/noise suppressor are properly formed, thereby increasing the photosensitivity.

In addition, the photosensitive layer composition for an optical sensor is 1,8-diiodooctane (DIO: 1,8-diiodooctane), 1-chloronaphthalene (1-CN: 1-chloronaphthalene), diphenyl ether (DPE: diphenylether) ), octane dithiol, and tetrabromothiophene may further include at least one additive selected from the group consisting of, but the additive is not particularly limited.

An optical sensor according to an embodiment of the present invention includes a first electrode; a second electrode provided to face the first electrode; a blocking layer provided between the first electrode and the second electrode; and a photosensitive layer comprising the above-described photosensitive layer composition for a photosensor provided between the blocking layer and the first electrode or between the blocking layer and the second electrode. However, other components may be interposed between each layer. 1 shows a structure of an optical sensor as an embodiment.

In one embodiment, the first electrode may be an anode. In addition, the first electrode may be a cathode.

The first electrode or the second electrode may be formed of fluorine-containing tin oxide, indium-containing tin oxide, aluminum-containing zinc oxide, indium-containing zinc oxide or a mixture thereof, or gold (Au), silver (Ag), platinum (Pt), respectively. , palladium (Pd), copper (Cu), aluminum (Al), carbon (C), cobalt sulfide (CoS), copper sulfide (CuS), nickel oxide (NiO), or mixtures thereof, but the compound is not particularly limited to. In a more preferred embodiment, the first electrode may include indium tin oxide (ITO), and the second electrode may include aluminum.

The first electrode and the second electrode are provided to face each other.

A substrate may be additionally disposed below the first electrode or above the second electrode. As the substrate, a glass substrate or a plastic substrate excellent in mechanical strength, thermal stability, transparency, surface smoothness, handling easiness and waterproofness may be used, but is not limited thereto. The composition for the first electrode or the second electrode may be formed on the substrate using a vapor deposition method or a sputtering method.

The blocking layer is provided between the first electrode and the second electrode. The blocking layer may be an electron blocking layer (EBL). The electron blocking layer can effectively block electrons moving to the anode without blocking the transmission of holes.

The photosensor of the present invention can realize thermal stability and fast response to light without a separate hole blocking layer by using the above-described photosensitive layer composition.

The photosensitive layer of the present invention may be provided between the blocking layer and the first electrode or between the blocking layer and the second electrode. The composition of the photosensitive layer is the same as described above.

In addition, in the optical sensor according to an embodiment of the present invention, the blocking layer is poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate), PEDOT : PSS), polyarylamine, poly(N-vinylcarbazole) (poly(N-vinylcarbazole), polyaniline, polypyrrole, N,N,N',N'-tetrakis(4-methyl) Toxyphenyl)-benzidine (N,N,N',N'-tetrakis(4-methoxyphenyl)-benzidine, TPD), 4,4'-bis[N-(1-naphthyl)-N-phenyl-amino] Biphenyl (4,4'-bis[N-(1-naphthyl)-N-phenyl-amino]biphenyl, α-NPD), m-MTDATA, 4,4',4"-tris(N-carbazolyl) -triphenylamine (4,4',4"-tris(N-carbazolyl)-triphenylamine, TCTA) or a mixture thereof, but is not particularly limited thereto.

In a more preferred embodiment, the blocking layer may include PEDOT:PSS (poly(3,4-ethylenediocy-thiophene) doped with poly(styrenesulfonic acid)). By using the above material, solution process and low temperature (100,000 °C or less) process are possible in the manufacture of photosensors, and the highest occupied molecular orbital (HOMO) energy level is appropriate as -5.0 eV, which can contribute to photocurrent amplification and dark current suppression. have.

The optical sensor manufacturing method of the present invention includes the step of ultrasonicating the first electrode substrate, and the first electrode substrate is as described above.

In addition, the optical sensor manufacturing method of the present invention may further include the step of oxidizing the surface of the ultrasonically treated substrate. As a method of oxidizing the substrate surface, a method of oxidizing the surface using a parallel plate-type electric discharge, a method of oxidizing the surface through ozone generated using UV ultraviolet rays in a vacuum state, or using oxygen radicals generated by plasma to oxidize, but is not particularly limited thereto. By performing the above step, it is possible to prevent oxygen desorption on the first electrode substrate.

In addition, the method for manufacturing an optical sensor of the present invention includes applying a blocking layer composition on the first electrode. The blocking layer may be an electron blocking layer, and may include PEDOT:PSS (poly(3,4-ethylenediocy-thiophene) doped with poly(styrenesulfonic acid)) as the electron blocking layer composition.

The barrier layer composition may be applied on the first electrode by a coating technique such as spin coating, slit coating, dip coating, inkjet printing, gravure printing, spray coating, doctor blade, bar coating, brush painting, etc., but the coating method is not particularly limited to.

In addition, the method for manufacturing a photosensor of the present invention includes the step of heat-treating the first electrode substrate to which the blocking layer composition is applied, whereby the photosensitive layer composition may be deposited on the blocking layer. As a more preferred embodiment, heat treatment may be performed at 120 to 160° C. for 5 to 20 minutes.

In addition, the method for manufacturing a photosensor of the present invention includes applying a photosensitive layer composition on the blocking layer. The photosensitive layer composition is the same as described above.

The photosensitive layer composition may be applied on the first electrode by a coating technique such as spin coating, slit coating, dip coating, inkjet printing, gravure printing, spray coating, doctor blade, bar coating, brush painting, etc., but the coating The method is not particularly limited.

In addition, the method for manufacturing a photosensor of the present invention includes depositing a second electrode on the applied photosensitive layer. The second electrode is the same as described above.

Hereinafter, the present invention will be described in more detail through the following Examples and Experimental Examples. However, the following examples and experimental examples are merely illustrative of the present invention, and the content of the present invention is not limited by the following examples.

<Example 1>

The ITO/glass substrate was cleaned and then sonicated in deionized water, acetone and isopropanol for 20 min each. The substrate was treated with UV ozone for 20 minutes to increase the surface energy. PEDOT:PSS (Heraeus Clevios ^TM , AI 4083, Heraeus, Hanau, Germany) was spin-coated on the substrate, and then thermal annealing was performed at 140° C. for 10 minutes. As a photosensitive layer composition, the material of Formula 1 as a photosensitive material and the material of Formula 3 as a light signal amplification/noise suppressor were mixed, and 1,8-diiodooctane (DIO, 3 vol.%) was used as a solvent. . The concentration of the solution was 5% by weight. A photosensor was manufactured by spin-coating the photosensitive layer and then thermally depositing aluminum to a thickness of 100,000 nm without a hole blocking layer.

<Comparative Example 1>

A photosensor was manufactured in the same manner as in Example 1, except that _{PC 71} BM material was used as an optical signal amplification/noise suppressor in the photosensitive layer composition.

<Experimental Example 1>

Current density (JV) according to voltage and external quantum efficiency according to wavelength were measured in the photosensors of Example 1 and Comparative Example 1 in the dark state, and the results are shown in FIGS. 3(a) and (b), respectively .

According to the above results, in the case of Comparative Example 1, the dark current value at -1V is 3.73 Х 10 ^-8 A/cm ² , whereas in Example 1, 39% is lower 1.13 Х 10 ^-9 A/cm ² of value could be confirmed.

In addition, it was confirmed that Comparative Example 1 exhibited an external quantum efficiency of 50% or less in the range of 500 nm to 740 nm, whereas Example 1 exhibited an external quantum efficiency of 20% or more on average.

<Experimental Example 2>

The result of calculating the light sensitivity (Detectivity) according to the wavelength of the optical sensor of Example 1 and Comparative Example 1 is shown in FIG. 4(a).

According to the above results, in the case of Comparative Example 1, 540nm, inde from -1V photosensitive value ^{3.25 Х 10 12 cm Hz 1/} 2 / W , while in Example 1, was 46% higher ^{1.61 Х 10 13 cm Hz 1/} 2 / It was confirmed that it has a value of W.

In addition, in the graph in which the photocurrent density is linearly increased as the light intensity of the photosensors of Example 1 and Comparative Example 1 is increased as shown in FIG. 4( b ), the photocurrent density is linear as the light intensity increases. It was confirmed that the values of the linear dynamic range (LDR), which mean the range increasing with , were 143 dB and 111 dB, respectively.

<Experimental Example 3>

In the photosensors of Example 1 and Comparative Example 1, the results of measuring the response time by turning the LED light source on and off with a power density of ^{6 mW/cm 2 at 592 nm are shown in FIGS. 5 (a) and (b).}

According to the above results, it can be seen that the response time of Example 1 is shorter than that of Comparative Example 1.

<Experimental Example 4>

In order to evaluate device stability, the results of measuring the photocurrent density of the photosensors of Example 1 and Comparative Example 1 in a light state and a dark state are shown in FIG. 6 , respectively.

According to the above results, it was confirmed that when light was applied, in Comparative Example 1, the photocurrent decreased by 6.2% in 10 minutes, whereas in Example 1, the photocurrent was maintained at 99% (FIG. 6(a)). In addition, it was confirmed that Example 1 exhibited excellent stability even in a dark state (FIG. 6(b)).

In addition, according to the results of measuring the photocurrent density after performing annealing at 100,000° C. to evaluate the thermal stability, in Comparative Example 1, the photocurrent was greatly reduced and rapidly increased by one time during the heat treatment process, whereas that of Example 1 In this case, it was confirmed that it was stable in both photocurrent and dark current (FIGS. 6(c), (d))

<Preparation Example 1-9>

After manufacturing the photosensors using the materials shown in Table 1, respectively, the results of measuring the sensitivity to voltage are shown in FIG. 7 .

first electrode barrier layer photosensitive layer
photosensitive material photosensitive layer
Optical signal amplification/noise suppressor barrier layer second electrode Preparation Example 1 ITO ZnO P3HT Formula 2 MoO ₃ or PEDOT Ag Preparation 2 ITO PEDOT:PSS PDTP-DPP PNDI BCP Al Preparation 3 Glass/MoOx/Ag MoOx PVK 2CzPN Bphen Ag Preparation 4 ITO ZnO Formula 1 IFIC-i-4F MoO3 Ag Preparation 5 ITO PEDOT:PSS P3HT PC71BM:ITIC Bphen Ag Preparation 6 ITO ZnO Formula 1 (PDI-BP)4- MoOx Al Preparation 7 ITO PEDOT:PSS P3HT IDIC - Al Preparation 8 ITO PEDOT:PSS Formula 1 PNDI-5DD, PNDI-2OD, PNDI-POD. ZnO Al Preparation 9 ITO PEDOT:PSS Formula 1 Formula 3 - Al

According to the above results, it can be confirmed that the photosensor of Preparation Example 9 has the highest sensitivity without a separate hole blocking layer.

Claims (14)

a first electrode;
a second electrode provided to face the first electrode;
a blocking layer provided between the first electrode and the second electrode; and
a photosensitive layer comprising a photosensitive layer composition for a photosensor provided between the blocking layer and the first electrode or between the blocking layer and the second electrode;
The photosensitive layer composition for the photosensor comprises a first photosensitive material comprising a compound represented by the following Chemical Formula 1 and an optical signal amplification/noise suppressor comprising a non-fullerene compound,
Light sensor:
[Formula 1]

(in Formula 1, n is a natural number).
The method of claim 1,
The bifullerene compound is a compound represented by the following formula (2),
Light sensor:
[Formula 2]

(In Formula 2, R1, R2, R3 and R4 are the same or different from each other, C1 to C20 alkyl group, alkenyl group, alkynyl group).
The method of claim 1,
The weight ratio of the optical signal amplification/noise suppressor comprising the first photosensitive material and the bifullerene compound is 1: 4 to 4: 1,
light sensor.
The method of claim 1,
The bifullerene compound comprises a compound represented by the following formula (3),
Light sensor:
[Formula 3]

.
The method of claim 1,
The photosensitive layer composition for the photosensor is PBDB-T (poly[(2,6-(4,8-bis(5-(2-ethylhexyl)thiophen-2-yl)-benzo[1,2-b:4] ,5-b']dithiophene))-alt-(5,5-(1',3'-di-2-thienyl-5',7'-bis(2-ethylhexyl)benzo[1',2'- c:4',5'-c']dithiophene-4,8-dione))), PCDTBT (Poly[N-9'-heptadecanyl-2,7-carbazole-alt-5,5-(4', 7′-di-2-thienyl-2′,1′,3′-benzothiadiazole)], PTB-7 (Poly[[4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b: 4,5-b′]dithiophene-2,6-diyl][3-fluoro-2-[(2-ethylhexyl)carbonyl]thieno[3,4-b]thiophenediyl]] and PTB7-Th(Poly[4, 8-bis(5-(2-ethylhexyl)thiophen-2-yl)benzo[1,2-b;4,5-b']dithiophene-2,6-diyl-alt-(4-(2-ethylhexyl) -3-fluorothieno[3,4-b]thiophene-)-2-carboxylate-2-6-diyl)] further comprising at least one second photosensitive material,
light sensor.
delete The method of claim 1,
The photosensitive layer composition for the photosensor is 1,8-diiodooctane (DIO: 1,8-diiodooctane), 1-chloronaphthalene (1-CN: 1-chloronaphthalene), diphenyl ether (DPE: diphenylether), Further comprising at least one additive selected from octane dithiol and tetrabromothiophene,
light sensor.
delete The method of claim 1,
The photosensor includes one blocking layer,
The one blocking layer is an electron blocking layer (EBL),
light sensor.
The method of claim 1,
The blocking layer comprises PEDOT:PSS (poly(3,4-ethylenediocy-thiophene) doped with poly(styrenesulfonic acid)),
light sensor.
The method of claim 1,
The first electrode is indium-containing tin oxide, aluminum-containing zinc oxide, indium-containing zinc oxide, or a mixture thereof,
light sensor.
The method of claim 1,
The second electrode is gold (Au), silver (Ag), platinum (Pt), palladium (Pd), copper (Cu), aluminum (Al), carbon (C), cobalt sulfide (CoS), copper sulfide (CuS) ), nickel oxide (NiO) or a mixture thereof,
light sensor.
In the method of manufacturing the optical sensor of claim 1,
ultrasonicating the first electrode substrate;
applying a barrier layer composition on the sonicated first electrode substrate;
heat-treating the first electrode substrate to which the barrier layer composition is applied;
applying a photosensitive layer composition on the blocking layer; and
Including; applying a second electrode on the applied photosensitive layer;
Optical sensor manufacturing method.
14. The method of claim 13,
oxidizing the sonicated surface of the first electrode substrate after sonicating the first electrode substrate and before applying the barrier layer composition on the first electrode substrate;
Optical sensor manufacturing method.

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