JP2020107737A - P-type organic semiconductor, composition, photoelectric conversion film, photoelectric conversion element and image sensor element - Google Patents

Abstract

To provide a p-type organic semiconductor, a photoelectric conversion film, a photoelectric conversion element and an image sensor element which are superior in heat resistance and enable detection of near infrared light.SOLUTION: A p-type organic semiconductor comprises a derivative of tin naphthalocyanine having R1 and R2 bound to a Sn atom as an axial substituent group, where R1 and R2 independently represent a substituted or unsubstituted alkyl group with 1-30 carbon atoms. The p-type organic semiconductor is superior in heat resistance because of having R1 and R2. Therefore, even if a photoelectric conversion film including the p-type organic semiconductor is formed by a resistive heating vapor deposition method, the thermal degradation of the p-type organic semiconductor can be suppressed and thus, the conversion efficiency of a photoelectric conversion element is increased.SELECTED DRAWING: None

Description

The present invention relates to a p-type organic semiconductor, a composition, a photoelectric conversion film, a photoelectric conversion element and an image sensor.

Since organic semiconductors can easily change their characteristics by changing their molecular structures, they have a wide variety of variations. Therefore, it is considered that the organic semiconductor can realize a function that cannot be realized by the inorganic semiconductor, and thus it is actively researched.

In recent years, development of an image sensor capable of simultaneously obtaining an image by visible light and an image by near infrared light has been advanced. Such an image sensor has a photoelectric conversion element (light receiving element) in which a photoelectric conversion film including a semiconductor capable of detecting near infrared light is formed between a pair of electrodes.

Here, in the case of an inorganic semiconductor, it is difficult to design so as to absorb only near infrared light.

On the other hand, in the case of an organic semiconductor, since it can be designed to absorb only near infrared light, an organic semiconductor is used for the photoelectric conversion film capable of detecting near infrared light.

For example, in Patent Document 1, a tin naphthalocyanine derivative is used as a p-type organic semiconductor included in a photoelectric conversion film capable of detecting near infrared light.

JP, 2016-225456, A

Here, the photoelectric conversion film containing the p-type organic semiconductor of Patent Document 1 can be formed by the resistance heating vapor deposition method, but the p-type organic semiconductor is thermally deteriorated, and as a result, the conversion efficiency of the photoelectric conversion element is increased. There is a problem of decrease.

An object of one embodiment of the present invention is to provide a p-type organic semiconductor that has excellent heat resistance and can detect near infrared light.

One embodiment of the present invention is a p-type organic semiconductor, which has the general formula (1):

［式中、Ｒ_１、Ｒ_２は、それぞれ独立に、置換もしくは無置換の炭素数１〜３０のアルキル基であり、Ｒ_３〜Ｒ_２６は、それぞれ独立に、水素原子、重水素原子、置換もしくは無置換のアルキル基、置換もしくは無置換のアリール基、置換もしくは無置換のアルコキシ基、置換もしくは無置換のアルキルチオ基、置換もしくは無置換のアリールオキシ基、置換もしくは無置換のアリールチオ基、置換もしくは無置換の複素環基で置換されたオキシ基、置換もしくは無置換の複素環基で置換されたチオ基、または、置換もしくは無置換のアミノ基である。］
で表される。

[In formula, R< ₁ >, R< ₂ > is a substituted or unsubstituted C1-C30 alkyl group each independently, R< ₃ >-R< ₂₆ > is a hydrogen atom, a deuterium atom, a substituted each independently. Or an unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted alkylthio group, a substituted or unsubstituted aryloxy group, a substituted or unsubstituted arylthio group, substituted or An oxy group substituted with an unsubstituted heterocyclic group, a thio group substituted with a substituted or unsubstituted heterocyclic group, or a substituted or unsubstituted amino group. ]
It is represented by.

According to one embodiment of the present invention, it is possible to provide a p-type organic semiconductor that has excellent heat resistance and is capable of detecting near infrared light.

It is a schematic sectional drawing which shows an example of the photoelectric conversion element of this embodiment. It is a schematic sectional drawing which shows the other example of the photoelectric conversion element of this embodiment. It is a schematic sectional drawing which shows the 1st example of the image sensor of this embodiment. It is a schematic sectional drawing which shows the 2nd example of the image sensor of this embodiment. It is a schematic sectional drawing which shows the 3rd example of the image sensor of this embodiment. It is a schematic perspective view which shows the 3rd example of the image sensor of this embodiment. It is a schematic sectional drawing which shows the 4th example of the image sensor of this embodiment. It is a schematic sectional drawing which shows the 5th example of the image sensor of this embodiment. It is a schematic perspective view which shows the 5th example of the image sensor of this embodiment.

Next, a mode for carrying out the present invention will be described.

Hereinafter, in the drawings, in order to clearly express a plurality of layers and regions, the thickness is enlarged and shown. In addition, in the drawings, unnecessary portions are omitted for the sake of clear explanation of the present embodiment. Further, throughout the specification, the same reference numerals are used for the same or similar components.

In addition, when a certain part such as a layer, a film, a region, or a plate is “above” another part, a certain part is “directly above” the other part, or a certain part and another part are Including the case where another portion is present between them. On the contrary, when a certain portion is “directly above” the other portion, it means that there is no other portion between the certain portion and the other portion.

[P-type organic semiconductor]
The p-type organic semiconductor of the present embodiment has the general formula (1)

［式中、Ｒ_１、Ｒ_２は、それぞれ独立に、置換もしくは無置換の炭素数１〜３０のアルキル基であり、Ｒ_３〜Ｒ_２６は、それぞれ独立に、水素原子、重水素原子、置換もしくは無置換のアルキル基、置換もしくは無置換のアリール基、置換もしくは無置換のアルコキシ基、置換もしくは無置換のアルキルチオ基、置換もしくは無置換のアリールオキシ基、置換もしくは無置換のアリールチオ基、置換もしくは無置換の複素環基で置換されたオキシ基、置換もしくは無置換の複素環基で置換されたチオ基、または、置換もしくは無置換のアミノ基である。］
で表される。

[In formula, R< ₁ >, R< ₂ > is a substituted or unsubstituted C1-C30 alkyl group each independently, R< ₃ >-R< ₂₆ > is a hydrogen atom, a deuterium atom, a substituted each independently. Or an unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted alkylthio group, a substituted or unsubstituted aryloxy group, a substituted or unsubstituted arylthio group, substituted or An oxy group substituted with an unsubstituted heterocyclic group, a thio group substituted with a substituted or unsubstituted heterocyclic group, or a substituted or unsubstituted amino group. ]
It is represented by.

Since the p-type organic semiconductor of the present embodiment is a tin naphthalocyanine derivative, it can detect near infrared light.

Further, the p-type organic semiconductor of the present embodiment has R ₁ and R ₂ as the axial substituents of the tin naphthalocyanine derivative, and therefore has excellent heat resistance. Therefore, even if the photoelectric conversion film containing the p-type organic semiconductor of the present embodiment is formed by the resistance heating vapor deposition method, the thermal deterioration of the p-type organic semiconductor of the present embodiment can be suppressed, and as a result, it will be described later. The conversion efficiency of the photoelectric conversion element is improved.

The alkyl group in R _{3 to} R ₂₆ is a linear, branched or cyclic alkyl group.

Examples of the linear alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, an octyl group, a decyl group, and a pentadecyl group.

Examples of the branched alkyl group include t-butyl group and the like.

Examples of the cyclic alkyl group include a cyclobutyl group, a cyclopentyl group, a cyclohexyl group and a cycloheptyl group.

The linear or branched alkyl group preferably has 1 to 20 carbon atoms, and more preferably 1 to 10 carbon atoms.

The cyclic alkyl group preferably has 3 to 20 carbon atoms, and more preferably has 3 to 12 carbon atoms.

The aryl group for R _{3 to} R ₂₆ is a monocyclic, non-fused polycyclic or fused polycyclic aryl group.

Examples of the monocyclic aryl group include a phenyl group and the like.

Examples of the non-fused polycyclic aryl group include a biphenyl group, a terphenyl group, a quaterphenyl group, a kink phenyl group, a sexiphenyl group, a fluoranthenyl group and a triphenylenyl group.

Examples of the condensed polycyclic aryl group include a naphthyl group, anthryl group, phenanthryl group, fluorenyl group, indenyl group, pyrenyl group, acetonaphthenyl group, bisphenylfluorenyl group, 9-(9-fluorenyl)fluorenyl group and the like. Are listed.

The ring-forming carbon number of the monocyclic, non-fused polycyclic or fused polycyclic aryl group is preferably 6 to 50, and more preferably 6 to 40.

The alkoxy group of R _{3 to} R _{26 and} the alkyl group in the alkylthio group are the same as the above-mentioned alkyl groups.

The aryloxy group of R _{3 to} R _{26 and} the aryl group in the arylthio group are the same as the above aryl groups.

The heterocyclic group in the oxy group substituted by the heterocyclic group of R _{3 to} R ₂₆ and the thio group substituted by the substituted or unsubstituted heterocyclic group is a monocyclic or polycyclic heterocyclic group.

Examples of the monocyclic heterocyclic group include a pyrrolyl group, an imidazolyl group, a pyrazolyl group, an oxazolyl group, an isoxazolyl group, an oxadiazolyl group, a thiazolyl group, a furanyl group, a pyranyl group, a thienyl group, a pyridyl group, a pyrazyl group, and a pyrimidinyl group. , Pyridazinyl group, triazinyl group, quinolyl group, isoquinolyl group and the like.

Examples of the polycyclic heterocyclic group include a benzo(pyridyl)furanyl group, benzofuranyl group, benzothienyl group, indolyl group, carbazolyl group, carborinyl group, phenanthridinyl group, acridinyl group, perimidinyl group, phenanthrolyl group. Examples thereof include a nyl group, a benzoxazolyl group, a benzothiazolyl group, a quinoxalyl group, a benzimidazolyl group, a pyrazolyl group, a dibenzofuranyl group and a dibenzothienyl group.

The ring-forming carbon number of the monocyclic or polycyclic heterocyclic group is preferably 5 to 50, and more preferably 5 to 30.

Among these, R _{3 to} R ₂₆ are preferably each independently a hydrogen atom or a deuterium atom. Thereby, the heat resistance of the p-type organic semiconductor can be further improved.

Examples of the substituent in R _{1 to} R ₂₆ include a cyano group, a silyl group, a monoalkylsilyl group having 1 to 10 carbon atoms, a dialkylsilyl group or a trialkylsilyl group, a straight chain having 1 to 10 carbon atoms, and a branched group. Or cyclic alkyl group, linear or branched alkoxy group having 1 to 10 carbon atoms, aryl group having 6 to 15 ring carbon atoms, aryloxy group having 6 to 15 ring carbon atoms, ring carbon number 6-15 arylcarbonyl group, heterocyclyl group having 3 to 32 ring carbon atoms, monoalkylamino group or dialkylamino group having 1 to 10 carbon atoms, monoarylamino group or diarylamino group having 6 to 15 ring carbon atoms And so on.

In the general formula (1), when R _{3 to} R ₂₆ are electron withdrawing groups such as halogen atoms (for example, F and Cl), an n-type organic semiconductor is obtained (for example, JP 2009-218369 A). reference).

The p-type organic semiconductor of the present embodiment has the general formula (2):

［式中、ｎ_１、ｎ_２は、それぞれ独立に、０〜１０の整数であり、Ｙ_１〜Ｙ_６は、それぞれ独立に、直鎖アルキル基であり、Ｒ_２７〜Ｒ_３０は、それぞれ独立に、水素原子または重水素原子である。］
で表されることが好ましい。これにより、ｐ型有機半導体の熱耐性をさらに向上させることができる。

[In the formula, n ₁ and n ₂ are each independently an integer of 0 to 10, Y _{1 to} Y ₆ are each independently a linear alkyl group, and R _{27 to} R ₃₀ are each independently. And a hydrogen atom or a deuterium atom. ]
It is preferable that Thereby, the heat resistance of the p-type organic semiconductor can be further improved.

[Composition]
The composition of the present embodiment contains the p-type organic semiconductor of the present embodiment and an n-type organic semiconductor. A photoelectric conversion film can be formed by using the composition of the present embodiment.

The n-type organic semiconductor is not particularly limited as long as it can form a pn junction with the p-type organic semiconductor of the present embodiment, and examples thereof include subphthalocyanine, fullerene and derivatives thereof, and thiophene and derivatives thereof. , Two or more kinds may be used in combination. Among these, fullerene and/or a fullerene derivative is preferable in terms of conversion efficiency of the photoelectric conversion film.

Examples of fullerenes include C50, C60, C70, C76, C78, C80, C82, C84, C90, C96, C240, C540 and the like.

In the derivative of fullerene, the fullerene is substituted with a substituent.

Examples of the substituent include the above-mentioned alkyl group, aryl group, and heterocyclic group.

[Photoelectric conversion element]
FIG. 1 shows an example of the photoelectric conversion element of this embodiment.

In the photoelectric conversion element 100, the (organic) photoelectric conversion film 30 is formed between the first electrode 10 and the second electrode 20 which face each other.

At least one of the first electrode 10 and the second electrode 20 is a translucent electrode capable of transmitting near infrared light.

Examples of the material forming the translucent electrode include conductive materials such as indium tin oxide (ITO), indium zinc oxide (IZO), AZO, FTO, SnO ₂ , TiO ₂ , and ZnO ₂ .

The translucent electrode may be formed of a single layer or a plurality of layers may be laminated.

When the first electrode 10 or the second electrode 20 is an opaque electrode that does not transmit near-infrared light, examples of the material forming the opaque electrode include aluminum (Al), copper, gold, and silver. And a conductive material such as polysilicon to which conductivity is imparted by being doped with impurities.

When forming the first electrode 10 and the second electrode 20, various methods can be applied depending on the material used.

For example, when forming an ITO electrode, a method such as an electron beam method, a sputtering method, a resistance heating vapor deposition method, a chemical reaction method (a sol-gel method or the like), a method of applying a dispersion liquid of indium tin oxide, or the like may be applied. it can.

In addition, when forming the first electrode 10 and the second electrode 20, UV-ozone treatment, plasma treatment, or the like may be performed.

Here, the first electrode 10 is an electrode that collects holes among the charges generated in the photoelectric conversion film 30. The second electrode 20 is an electrode that collects electrons in the charges generated in the photoelectric conversion film 30.

By applying a bias voltage between the first electrode 10 and the second electrode 20, holes of the charges generated in the photoelectric conversion film 30 are moved to the first electrode 10 and electrons are transferred to the second electrode. Can be moved to the electrode 20 of FIG.

Here, when the photoelectric conversion element 100 is applied to an image sensor described later, the photoelectric conversion element 100 is converted into a voltage signal according to the amount of holes moved to the first electrode 10 and read. Thereby, the near infrared light can be converted into a voltage signal and extracted.

A bias voltage may be applied so that the first electrode 10 collects electrons and the second electrode 20 collects holes.

The photoelectric conversion film 30 is a film containing the p-type organic semiconductor of the present embodiment and the n-type organic semiconductor, and the p-type organic semiconductor of the present embodiment and the n-type organic semiconductor form a pn junction. When the photoelectric conversion film 30 receives near infrared light, excitons are generated. After the excitons are separated into holes and electrons, the holes move to the first electrode 10 and the electrons move to the second electrode 20. As a result, a current flows through the photoelectric conversion element 100.

The n-type organic semiconductor is the same as the n-type organic semiconductor contained in the composition of the present embodiment.

The photoelectric conversion film 30 may be formed of a single layer or a plurality of layers may be laminated.

Examples of the photoelectric conversion film 30 formed of a single layer include an intrinsic semiconductor layer.

As the laminated structure of the photoelectric conversion film 30 in which a plurality of layers are laminated, for example, p-type semiconductor layer/intrinsic semiconductor layer, intrinsic semiconductor layer/n-type semiconductor layer, p-type semiconductor layer/intrinsic semiconductor layer/n-type semiconductor Layer, p-type semiconductor layer/n-type semiconductor layer, and the like.

The intrinsic semiconductor layer includes the p-type organic semiconductor of the present embodiment and the n-type organic semiconductor.

The volume ratio of the n-type organic semiconductor to the p-type organic semiconductor of the present embodiment in the intrinsic semiconductor layer is preferably 0.01 to 100, more preferably 0.02 to 95. Thereby, the conversion efficiency of the photoelectric conversion film 30 can be further improved.

The p-type semiconductor layer includes the p-type organic semiconductor of this embodiment.

The n-type semiconductor layer contains an n-type organic semiconductor.

The thickness of the photoelectric conversion film 30 is preferably 1 nm to 800 nm, more preferably 5 nm to 500 nm. Thereby, the conversion efficiency of the photoelectric conversion film 30 can be further improved.

The photoelectric conversion film 30 is preferably formed by a dry film formation method, more preferably by a resistance heating vapor deposition method, but may be formed by a wet film formation method.

Examples of the dry film forming method include a vacuum vapor deposition method.

Specific examples of the vacuum vapor deposition method include an electron beam method, a sputtering method, and a resistance heating vapor deposition method.

Examples of the wet film forming method include a solution coating method.

Specific examples of the solution coating method include a casting method, a spin coating method, a dip coating method, a blade coating method, a wire bar coating method, a spray coating method, an inkjet printing method, a screen printing method, an offset printing method and a relief printing method. Can be mentioned.

Specific examples of the patterning method when the photoelectric conversion film 30 needs to be patterned include a resist etching method and a laser removal method.

FIG. 2 shows another example of the photoelectric conversion element of this embodiment.

In the photoelectric conversion element 200, the electron blocking layer 40 and the hole blocking layer 45 are formed between the first electrode 10 and the photoelectric conversion film 30, and between the second electrode 20 and the photoelectric conversion film 30, respectively. The photoelectric conversion device 100 is the same as the photoelectric conversion device 100 except that it is provided.

The electron blocking layer 40 suppresses the injection of electrons from the first electrode 10 into the photoelectric conversion film 30, and also prevents the electrons generated in the photoelectric conversion film 30 from moving to the first electrode 10.

The hole blocking layer 45 suppresses the injection of holes from the second electrode 20 into the photoelectric conversion film 30, and also prevents the holes generated in the photoelectric conversion film 30 from moving to the second electrode 20. Inhibit.

Examples of the material forming the electron blocking layer 40 include poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS), polyarylamine, poly(N-vinylcarbazole), polyaniline, Polypyrrole, N,N,N′,N′-tetrakis(4-methoxyphenyl)benzidine (TPD), 4,4′-bis[N-(1-naphthyl)-N-phenyl-amino]biphenyl (α-NPD ), m-MTDATA, 4,4′,4″-tris(N-carbazolyl)triphenylamine (TCTA) and the like, and two or more kinds may be used in combination.

Examples of the material forming the hole blocking layer 45 include naphthalene-1,4,5,8-tetracarboxylic dianhydride (NTCDA), batocproine (BCP), LiF, Alq3, Gaq3, Inq3, Znq2, Zn. (BTZ)2, BeBq2, etc. may be mentioned, and two or more kinds may be used in combination.

The electron blocking layer 40 or the hole blocking layer 45 may be omitted.

A bias voltage may be applied so that the first electrode 10 collects electrons and the second electrode 20 collects holes. In this case, the hole blocking layer 40 and the electron blocking layer 45 may be formed instead of the electron blocking layer 40 and the hole blocking layer 45, respectively.

The photoelectric conversion element of this embodiment can be applied to an image sensor, a solar cell, a photodetector, a photosensor, a photodiode, and the like.

[Image sensor]
FIG. 3 shows an example of the image sensor of this embodiment.

The image sensor 300 includes a semiconductor substrate 310, an insulating layer 80, and the photoelectric conversion element 100.

The semiconductor substrate 310 is a silicon substrate, on which the transfer transistor and the charge storage location 55 are integrated. Here, the transfer transistor and the charge storage location 55 are integrated for each pixel, the charge storage location 55 is electrically connected to the photoelectric conversion element 100, and the information of the charge storage location 55 is the transmission transistor. Transferred by.

Metal wiring and pads are provided on the semiconductor substrate 310.

The material forming the metal wiring and the pad is not particularly limited as long as it can reduce the signal delay, and examples thereof include aluminum (Al), copper (Cu), silver (g), and alloys thereof). A metal having a low specific resistance can be used.

An insulating layer 80 is formed on the semiconductor substrate 310 on which the metal wiring and the pads are formed.

Examples of the material forming the insulating layer 80 include inorganic insulating materials such as silicon oxide and silicon nitride, and materials having a low relative dielectric constant (Low-k materials) such as SiC, SiCOH, SiCO, and SiOF.

The insulating layer 80 has a contact hole for exposing the pad and a through hole 85 for exposing the charge storage area 55 of each pixel.

The photoelectric conversion element 100 is formed on the insulating layer 80.

The photoelectric conversion element 100 includes the first electrode 10, the photoelectric conversion film 30, and the second electrode 20 as described above, but the second electrode 20 can transmit near infrared light. Transparent electrode. Therefore, when light including near-infrared light enters from the second electrode 20 side, the near-infrared light is absorbed by the photoelectric conversion film 30 and photoelectrically converted.

A bandpass filter that transmits only near-infrared light may be provided above the photoelectric conversion element 100.

FIG. 4 shows a second example of the image sensor of this embodiment.

The image sensor 400 has the same configuration as the image sensor 300 except that the photoelectric conversion element 200 is applied instead of the photoelectric conversion element 100.

5 and 6 show a third example of the image sensor of this embodiment.

The image sensor 500 includes a semiconductor substrate 310, a lower insulating layer 60, a color filter layer 70, an upper insulating layer 80, and a photoelectric conversion element 100.

The semiconductor substrate 310 is a silicon substrate on which the photosensitive elements (50G, 50B, 50R), the transfer transistor, and the charge storage location 55 are integrated. Here, the photosensitive elements (50G, 50R, 50B) are silicon photodiodes. Further, the photosensitive elements (50G, 50B, 50R), the transfer transistor, and the charge storage location 55 are integrated for each pixel, and the photosensitive elements (50G, 50B, 50R) are green pixel, blue pixel, and red pixel, respectively. Included in the pixel and the charge storage location 55 is included in the near infrared pixel.

The photosensitive elements (50G, 50B, 50R) sense green light, blue light and red light, respectively, and the sensed information is transferred by the transmission transistor. The charge storage location 55 is electrically connected to the photoelectric conversion element 100, and the information in the charge storage location 55 is transferred by the transfer transistor.

Although the metal wiring and the pad are provided on the semiconductor substrate 310, the metal wiring and the pad may be provided below the photosensitive element (50G, 50B, 50R).

The lower insulating layer 60 is formed on the semiconductor substrate 310 on which the metal wiring and the pads are formed.

As the material forming the lower insulating layer 60, the same material as the material forming the insulating layer 80 can be used.

A color filter layer 70 is formed on the lower insulating layer 60.

The color filter layer 70 includes a blue filter 70B formed in a blue pixel, a green filter 70G formed in a green pixel, and a red filter 70R formed in a red pixel.

An upper insulating layer 80 is formed on the color filter layer 70 in order to remove a step due to the color filter layer 70 and flatten it.

The upper insulating layer 80 and the lower insulating layer 60 are formed with a contact hole exposing a pad and a through hole 85 exposing a charge storage location 55.

The photoelectric conversion element 100 is formed on the upper insulating layer 80.

The photoelectric conversion element 100 includes the first electrode 10, the photoelectric conversion film 30, and the second electrode 20 as described above. Here, the first electrode 10 is a translucent electrode capable of transmitting near infrared light and visible light. The second electrode 20 is a translucent electrode capable of transmitting visible light. Therefore, when light including near infrared light and visible light enters from the second electrode 20 side, the near infrared light is absorbed by the photoelectric conversion film 30 and photoelectrically converted. On the other hand, the light that is not absorbed by the photoelectric conversion film 30 passes through the first electrode 10 and the color filter layer 70, and is then sensed by the photosensitive element (50G, 50B, 50R).

Note that a bandpass filter that transmits only visible light and near infrared light may be provided above the photoelectric conversion element 100.

FIG. 7 shows a fourth example of the image sensor of this embodiment.

The image sensor 600 has the same configuration as the image sensor 500 except that the photoelectric conversion element 200 is applied instead of the photoelectric conversion element 100.

8 and 9 show a fifth example of the image sensor according to this embodiment.

The image sensor 700 includes a semiconductor substrate 310, an insulating layer 80, and a photoelectric conversion element 100, similarly to the image sensor 500. The semiconductor substrate 310 includes a photosensitive element (50G, 50B, 50R), a transmission transistor, and a charge. The storage locations 55 are collected.

However, the image sensor 700 is different from the image sensor 500 in that the photosensitive elements 50B, 50G and 50R are laminated and the color filter layer 70 is omitted.

The photosensitive elements 50B, 50G, and 50R are electrically connected to the charge storage location, and the information of the charge storage location is transferred by the transfer transistor.

The photosensitive elements 50B, 50G, and 50R can selectively absorb blue light, green light, and red light, respectively, depending on the stacking depth.

The image pickup element 700 can be miniaturized because the photoelectric conversion element 100 and the photosensitive elements 50B, 50G, and 50R are laminated.

Note that an organic photoelectric conversion element capable of selectively absorbing green light, blue light, and red light may be used instead of the photosensitive elements (50G, 50B, 50R). As a result, the sensitivity of the image sensor is improved and crosstalk can be reduced.

In this case, the order of stacking the photoelectric conversion element 100 and the organic photoelectric conversion element capable of selectively absorbing green light, blue light, and red light is not particularly limited.

Further, the photoelectric conversion element 200 may be applied instead of the photoelectric conversion element 100.

The image sensor of this embodiment can be applied to various electronic devices such as mobile phones and digital cameras.

Examples of the present invention will be described below. However, the technical scope of the present invention is not limited to the following examples.

[Example 1]
After stirring 1,3-Diiminobenz[f]isoindolinine (2.0 g) (manufactured by Tokyo Kasei) and Di-t-butyltin dichloride (1.5 g) (manufactured by Aldrich) under reflux in 1-Chloronaphthalene for 2 hours. The reaction mixture was returned to room temperature. Next, the precipitate was filtered and then washed with chloroform, pyridine and methanol to obtain Compound 1 (1.5 g) as a p-type organic semiconductor.

［比較例１］
ｐ型有機半導体として、スズナフタロシアニン（Ａｌｄｒｉｃｈ製）を用いた。

[Comparative Example 1]
Tin naphthalocyanine (manufactured by Aldrich) was used as the p-type organic semiconductor.

[Heat resistance of p-type organic semiconductor]
The heat resistance of the p-type organic semiconductor was evaluated by measuring the temperature at which the weight loss was 2% and 5% using TG-DTA.

Table 1 shows the evaluation results of the heat resistance of the p-type organic semiconductor.

表１から、実施例１のｐ型有機半導体は、熱耐性に高いことがわかる。

From Table 1, it can be seen that the p-type organic semiconductor of Example 1 has high heat resistance.

On the other hand, the p-type organic semiconductor of Comparative Example 1 has low heat resistance because the axial substituent of tin naphthalocyanine is not introduced.

[Example 2]
Chemical formula was applied on a glass substrate with ITO (film thickness: 150 nm) to a film thickness of 20 nm by a heating vapor deposition method.

で表される化合物Ａを成膜して、電子ブロッキング層を形成した。次に、抵抗加熱蒸着法により、実施例１のｐ型有機半導体と、ｎ型有機半導体としての、フラーレンＣ６０を、体積比が１：１、膜厚が１５０ｎｍとなるように成膜して、光電変換膜を形成した。さらに、高周波マグネトロンスパッタ法により、膜厚が１０ｎｍとなるようにＩＴＯ膜を成膜して、光電変換素子を得た。

A compound A represented by the following formula was formed into a film to form an electron blocking layer. Next, a p-type organic semiconductor of Example 1 and a fullerene C60 as an n-type organic semiconductor were formed by a resistance heating vapor deposition method so that the volume ratio was 1:1 and the film thickness was 150 nm. A photoelectric conversion film was formed. Further, an ITO film was formed to have a film thickness of 10 nm by a high frequency magnetron sputtering method to obtain a photoelectric conversion element.

The degree of vacuum in the above vacuum process was set to 4×10 ⁻⁴ Pa or less.

[Comparative example 2]
A photoelectric conversion element was obtained in the same manner as in Example 2 except that the p-type organic semiconductor of Comparative Example 1 was used instead of the p-type organic semiconductor of Example 1.

[IPCE of photoelectric conversion element]
After transferring the photoelectric conversion element to a glove box in which the concentration of water and oxygen is kept at 1 ppm or less without exposing it to the atmosphere, UV-curing resin is used, and a glass sealing can is applied with a hygroscopic agent. Sealed.

Using an IPCE measurement system (manufactured by Mac Science), the external quantum efficiency (IPCE) at the maximum conversion efficiency at wavelengths of 810 nm and 940 nm was measured with a negative bias of 3 V applied to the lower electrode of the photoelectric conversion element.

Table 2 shows the evaluation results of IPCE of the photoelectric conversion element.

表２から、実施例２の光電変換素子は、波長８１０ｎｍおよび９４０ｎｍのいずれにおいても、ＩＰＣＥが高いことがわかる。

From Table 2, it can be seen that the photoelectric conversion element of Example 2 has a high IPCE at both wavelengths of 810 nm and 940 nm.

On the other hand, the photoelectric conversion element of Comparative Example 2 contains the p-type organic semiconductor of Comparative Example 1, and thus has a low IPCE. It is considered that this is because the p-type organic semiconductor of Comparative Example 1 was thermally deteriorated when the photoelectric conversion film was formed by the resistance heating vapor deposition method.

10 1st electrode 20 2nd electrode 30 Photoelectric conversion film 100,200 Photoelectric conversion element 300,400,500,600,700 Imaging element

Claims (9)

General formula (1)

[In formula, R< ₁ >, R< ₂ > is a substituted or unsubstituted C1-C30 alkyl group each independently, R< ₃ >-R< ₂₆ > is a hydrogen atom, a deuterium atom, a substituted each independently. Or an unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted alkylthio group, a substituted or unsubstituted aryloxy group, a substituted or unsubstituted arylthio group, substituted or An oxy group substituted with an unsubstituted heterocyclic group, a thio group substituted with a substituted or unsubstituted heterocyclic group, or a substituted or unsubstituted amino group. ]
A p-type organic semiconductor represented by. General formula (2)

[Wherein, n ₁ and n ₂ are each independently an integer of 0 to 10, Y _{1 to} Y ₆ are each independently a linear alkyl group, and R _{27 to} R ₃₀ are each independently. And a hydrogen atom or a deuterium atom. ]
The p-type organic semiconductor according to claim 1, represented by: The p-type organic semiconductor according to claim 1, wherein R _{3 to} R ₂₆ are each independently a hydrogen atom or a deuterium atom. The p-type organic semiconductor according to any one of claims 1 to 3,
A composition comprising an n-type organic semiconductor. The composition according to claim 4, wherein the n-type organic semiconductor is a fullerene and/or a derivative of a fullerene. The p-type organic semiconductor according to any one of claims 1 to 3,
A photoelectric conversion film containing an n-type organic semiconductor. The photoelectric conversion film according to claim 6, which is formed by a vacuum vapor deposition method. A photoelectric conversion element comprising the photoelectric conversion film according to claim 6. An image pickup device comprising the photoelectric conversion device according to claim 8.

Images