EP3973580A1

EP3973580A1 - Photodetector with improved detection result

Info

Publication number: EP3973580A1
Application number: EP20726408.6A
Authority: EP
Inventors: Rico Meerheim; Robert Brückner; Matthias JAHNEL; Karl Leo
Original assignee: Senorics GmbH
Current assignee: Senorics GmbH
Priority date: 2019-05-20
Filing date: 2020-05-15
Publication date: 2022-03-30
Also published as: KR20220010480A; CN113841256A; DE102019113343A1; JP2022533408A; US20220199840A1; WO2020234171A1

Abstract

The invention relates to different aspects of a photodetector (1-8) for detecting electromagnetic radiation in a spectrally selective manner, comprising a first optoelectronic component (100-106, 108) for detecting a first wavelength of the electromagnetic radiation. The first optoelectronic component (100-106, 108) has a first optical cavity and at least one detection cell (21, 21a, 22, 22a, 23) arranged in the first optical cavity. The first optical cavity is made of two mutually spaced parallel mirror layers (11, 11a, 11', 12, 12a). The length of the first optical cavity is configured such that for the first wavelength, a resonant wave (13, 13a), which is associated with said wavelength, of the i-th order is formed in the first optical cavity. Each detection cell (21, 21a, 22, 22a, 23) has a photoactive layer (210, 220, 230), each photoactive layer being arranged within the first optical cavity such that precisely one vibration maximum of the resonant wave (13, 13a) lies within the photoactive layer (210, 220, 230). According to a first aspect of the invention, the order of the resonant wave (13, 13a) of the first optoelectronic component (100-106, 108) is greater than 1, and at least one optically absorbent intermediate layer (30, 31) and/or at least one optically transparent contact layer (50) is arranged in the optical cavity. According to a second aspect, the first optoelectronic component (110, 110') has at least one optically transparent spacer layer (40) in addition to the detection cell (21, 21'), said spacer layer being arranged in the first optical cavity between one of the mirror layers (11, 12) and the detection cell (21, 21'), and at least one outer contact (60, 60'), which adjoins an outer surface of the detection cell (21, 21') and consists of an electrically conductive material.

Description

Photodetector with improved detection result

The invention relates to a photodetector for spectrally selective detection of electromagnetic radiation, which has an optoelectronic component with an optical cavity and at least one detection cell arranged therein and enables an improved detection result.

Photodetectors for spectrally selective detection of electromagnetic radiation are used for the qualitative and quantitative detection of electromagnetic radiation, also referred to below as light, of a specific wavelength in an incident radiation. The incident radiation is broadband radiation that contains light of many different wavelengths. Such photodetectors often have filters or an optical cavity, which only allows specific wavelengths of the incident radiation to resonate within the cavity. The optical cavity is created by mirrors, at least one of which is semi-transparent and which are arranged at a distance L from one another. Within the optical cavity, the radiations (electromagnetic waves) of the resonance wavelengths are reflected and amplified several times between the mirrors and pass through a photoactive layer that converts the electromagnetic radiation into electrical power. Such a photodetector is described, for example, in WO 2017/029223 A1. Each of the resonance waves has a natural number of oscillation maxima within the optical cavity and is called a resonance wave i. Denotes order, where i corresponds to the number of oscillation maxima. All 1st to nth order resonance waves formed contribute to the electrical signal of the photodetector. This means that a specific wavelength of the resonance waves can only be detected in a restricted range for the wavelength to be detected or with great external effort, e.g. by upstream filters or a complex evaluation of the measured electrical signal.

Another essential factor for the accuracy of the detection of a specific wavelength in the optical cavity is the width of the wavelength range amplified by the optical cavity. Because although individual resonance wavelengths were mentioned above, with ideally only these individual resonance wavelengths forming standing waves, in reality a certain wavelength range around the individual resonance wavelengths is amplified in the optical cavity and forms standing waves. The amplification of the optical cavity, which determines the external quantum efficiency (EQE) for a given wavelength, is approximately a sequence of super-Gaussian distributions or Lorentz distributions, the maximum value in each case being at a resonance wavelength. The resonance wavelengths are plotted spectrally, ie in the representation of the magnitude of the gain of the photodetector over the wavelength, recognizable as a peak. The peak width is the width of the wavelength range in which the peak lies and at the limits of which the gain has reached half of the maximum. The larger the peak width, the more imprecise the detection, since wavelengths within the amplified wavelength range can no longer be distinguished from one another. This is described by the cavity quality Q, which is calculated approximately as the quotient of the peak wavelength and the peak width.

The object of the present application is to provide a photodetector for the spectrally selective detection of electromagnetic radiation with an optical cavity, which enables improved detection. In addition, a space-saving construction of a photodetector for the detection of electromagnetic radiation of several different wavelengths is to be provided, which allows miniaturization of the detectors or spectrometers.

This object is achieved by a photodetector according to one of the independent claims. Advantageous developments and embodiments are contained in the dependent claims.

A photodetector for spectrally selective detection of electromagnetic radiation according to a first aspect of the invention contains a first optoelectronic component for detecting a first wavelength of the electromagnetic radiation. The mere presence or absence of the first wavelength in the electromagnetic radiation incident on the photodetector (qualitative statement) and / or the intensity of the radiation of the first wavelength in the incident electromagnetic radiation (quantitative statement) can be detected. The first optoelectronic component has a first optical cavity and at least one detection cell arranged in the first optical cavity. The first optical cavity is formed by two parallel mirror layers which are spaced apart from one another. For all optical cavities of the present application, the distance between the two mirror layers is referred to as the physical length of the optical cavity, hereinafter also referred to as the length of the optical cavity for short. The length of the first optical cavity is designed in such a way that a resonance wave i associated therewith occurs for the first wavelength. Forms order in the first optical cavity. The following relationship generally applies to the ratio of a wavelength of the incident radiation that fulfills the resonance criterion and the physical length of the optical cavity: where L is the physical length of the optical cavity, l the incident wavelength, a the angle of incidence of the incident radiation with respect to the normal to the surface of the optoelectronic component on which the incident radiation strikes, n the effective refractive index over the entire optical cavity and possibly further intervening layers and i is the order of the resonance wave resulting from the incident wavelength. I is a natural number. According to the order i of the resonance wave belonging to the first wavelength, the optoelectronic component is also used as component i. Called order.

When “the resonance wave” is spoken of in the following description, what is meant is the resonance wave that belongs to the wavelength to be detected in the respective optoelectronic component, unless expressly stated otherwise.

Each detection cell arranged in the first optical cavity contains a photoactive layer. The photoactive layer preferably extends over the entire cross-sectional area of the first optical cavity, the cross-sectional area running perpendicular to the length of the first optical cavity. The photoactive layer of a detection cell is arranged within the first optical cavity in such a way that exactly one oscillation maximum of the resonance wave lies within the photoactive layer. In other words: depending on the order of the resonance wave generated by the first wavelength to be detected, the photoactive wave is Layer arranged within the optical cavity. The location of the oscillation maximum, i.e. the location of the intensity maximum of the electromagnetic field of the resonance wave, is preferably in the center of the photoactive layer based on the thickness of the photoactive layer, which is measured in the direction of the length of the first optical cavity. The layer thickness of the photoactive layer is preferably dimensioned in such a way that a node of the resonance wave which is adjacent to the oscillation maximum lying in the photoactive layer is no longer in the photoactive layer.

According to the invention, the order of the resonance wave of the first optoelectronic component is greater than 1. In other words: In the first optoelectronic component, a first wavelength, which forms a resonance wave of the 2nd, 3rd, 4th or higher order in the first optical cavity, is detected , since the photoactive layer is arranged in exactly one oscillation maximum of this resonance wave. Since higher-order resonance waves have significantly smaller peak widths than first-order resonance waves, which were detected in the prior art, a finer differentiation of different wavelengths, ie a better spectral resolution of the photodetector, can be achieved.

Preferably at least one of the detection cells has a first charge transport layer and a second charge transport layer, the photoactive layer being arranged between the first and the second charge transport layer. The individual layers are arranged one above the other along the length of the first optical cavity. The first and second charge transport layers also preferably extend over the entire cross-sectional area of the first optical cavity, the first charge transport layer being adjacent to a first surface of the photoactive layer and the second charge transport layer being adjacent to a second surface of the photoactive layer and the second surface being opposite the first surface . The charge transport layers serve to improve the charge extraction from the photoactive layer and its conduction to electrical contacts, also called electrodes, which forward the electrical signals generated in the detection cell to an evaluation unit which is suitable for evaluating them. These charge transport layers are particularly advantageous in the case of very thin photoactive layers with a thickness of less than 10 nm and then formed with a thickness greater than or equal to 10 nm. In the case of thicker photoactive layers, the charge transport layers can also be made very thin, for example with a thickness in the range from 1 nm to 5 nm, which means that they can also be referred to as injection or extraction layers. In both cases, the charge transport layers do not always have to be doped layers.

The mirror layers can be designed as highly reflective metallic layers, for example made of silver (Ag) or gold (Au), semitransparent mixed metal layers, for example made of Ag: Ca, or as dielectric mirrors (DBR - distributed Bragg reflector). At least one of the mirror layers is semitransparent in order to allow the incident light into the optical cavity, while the other mirror layer can be opaque. This property can be set, for example, via the thickness of the mirror layer and / or the materials and mixing ratios of the constituents of the mirror layers, which is known to the person skilled in the art. If the mirror layers consist of a material with good electrical conductivity, such as a conductive oxide, a conductive organic compound or a metal, the mirror layers can act as electrodes for forwarding the electrical signals generated in the detection cell to an evaluation unit that is suitable for evaluating them, serve. The evaluation unit is not necessarily part of the photodetector, but can be rigidly connected to it and on or in the same substrate, on which the photodetector is formed. In the case of a dielectric mirror, a thin layer of a material with good electrical conductivity, for example a thin metal layer, can be arranged on the last dielectric layer of the mirror layer facing the detection cell, so that in this case too the mirror layer can serve as an electrode. Further options for making electrical contact with the detection cells are explained later.

The following materials come into consideration as photoactive layers, in particular for the detection of wavelengths in the near infrared range (NIR) with 800 nm <1, <10 pm: fullerenes, for example C60 or C70, mixed with donors such as materials from the group of substances Phthalocyanines (such as zinc phthalocyanine or iron phthalocyanine), pyrans, e.g. bispyranilides (also abbreviated to TPDP), fulvalene, e.g. tetrathiofulvalene (also abbreviated to OMTTF) and aromatic amines (e.g. N, N, N ', N'-Tetrakis ( 4-methoxyphenyl) benzidine (also abbreviated to MeO-TPD), 2,7-bis [N, N-bis (4-methoxyphenyl) amino] 9,9-spirobifluorene (also abbreviated to Spiro-MeO-TPD) or 4,4 ', 4 "-Tris (3-methylphenylphenylamino) triphenylamine (also abbreviated to m-MTDATA)), the bisthiopyranilidenes, the bipyridinylidenes or the diketopyrrolopyrroles. Substances such as HatCN: BFDPB, HATCN: 4P-TPD would also be possible , HATCN: a-NPB. Any other desired photoactive materials can of course also be used, for example polymers, welc He was generated by means of liquid processing, such as from the group of polythiophenes (e.g. poly (2,5-bis (3-alkylthiophene-2-yl) thieno [3,2-b] thiophenes (also abbreviated to pBTTT).

A photoactive layer preferably has a thickness in the range from 0.1 nm to 1 μm, the thickness of the photoactive layer depending both on the material of the photoactive layer and on the overall structure of the optoelectronic component. Particularly preferred is the thickness of the photoactive layer for charge transfer photodiodes (CTPD) which use the direct interchromophoric charge transfer state, e.g. C60: TPDP, in the range from 10 nm to 1000 nm, while for photodiodes which use direct material absorption and in bulk or flat heterojunctions (BHJ, FHJ) they separate the charge carriers, e.g. C60: ZnPc, in the range from 0.1 nm to 100 nm.

For example, aromatic amines (such as N, N, N ', N'-tetrakis (4-methoxyphenyl) benzidines (also abbreviated to MeO-TPD), 2,7-bis [N, N-bis (4-methoxy- phenyl) amino] 9,9-spiro-bifluorene (also abbreviated to Spiro-MeO-TPD) or N4, N4'- bis (9,9-dimethyl-9H-fluoren-2-yl) -N4, N4'-diphenylbiphenyl- 4,4'-diamine (also abbreviated to BF-DPB) or 9,9-bis [4- (N, N-bis-biphenyl-4-yl-amino) phenyl] -9H-fluorene (also abbreviated to BPAPF)) or Polymers such as Po-3,4-ethylenedioxythiophene poly (styrene sulfonate (short PEDOT: PSS), SpiroTTB, NDP9, F6-TCNNQ, C60F48, BPhen, C60, HatnaCI6, MH250, W2 (hpp) 4, Cr2 (hpp) 4, NDN26 can be used. Of course, other suitable materials or a combination of at least two of the named materials can also be used. The material of the first charge transport layer differs from the material of the second charge transport layer of a detection cell in that one material is an electron-conducting material and the other is a hole-conducting material. The material of the charge transport layers can be a doped material, but does not have to be.

The electrical conductivity of the charge transport layers is preferably in the range of greater than 10 ⁵ S / cm. The thickness of the charge carrier transport layers is preferably in the range from 1 nm to 100 nm, the thickness generally decreasing as the number of detection cells in the first optical cavity increases. Furthermore, the thickness of the first charge transport layer of a detection cell can be different from the thickness of the second charge transport layer of this detection cell.

If different detection cells are present in the first optical cavity, the photoactive layers and - if present - the first charge transport layers and the second charge transport layers of the different detection cells can differ from one another in terms of material and thickness.

In any case, it goes without saying that the sum of the thicknesses of all layers present in the first optical cavity, that is to say photoactive layer or layers, possibly charge transport layers and / or further layers, is equal to the length of the first optical cavity.

In one embodiment, the number of detection cells arranged in the first optical cavity corresponds to the order of the resonance wave. This means that the first optoelectronic component contains exactly two detection cells, the photoactive layers of which are each arranged in exactly one and different vibration maximum of the resonance wave, if the first wavelength belonging to the 2nd order resonance wave is to be detected; contains exactly three detection cells if the first wavelength belonging to the 3rd order resonance wave is to be detected, etc. The detection cells are arranged one above the other along the length of the first optical cavity, but do not have to adjoin one another.

Alternatively, a smaller number of detection cells than the order of the resonance wave can also be arranged in the first optical cavity. So is for example Detection of a resonance wave of the second, third or higher order, in principle, a detection cell is sufficient, the photoactive layer of which is arranged within the optical cavity in such a way that precisely one oscillation maximum of the resonance wave lies therein. This simplifies the production of the photodetector and reduces the production costs by using simple and inexpensive materials instead of the detection cells that are not formed.

At least one optically absorbing intermediate layer is preferably arranged in the first optical cavity in such a way that precisely one oscillation node of the resonance wave lies in the optically absorbing intermediate layer. For optoelectronic components that are designed to detect resonance waves of a higher order than the 2nd order, a plurality of optically absorbing intermediate layers are preferably arranged so that each node of the resonance wave lies in exactly one optically absorbing intermediate layer. The at least one optically absorbing intermediate layer serves to absorb resonance waves of a different order than that of the resonance wave belonging to the first wavelength. In particular, resonance waves which are adjacent to the resonance wave belonging to the first wavelength are canceled in the nodes, while the resonance wave belonging to the first wavelength is hardly influenced. In this way, the assignment of a detected electrical signal to the first wavelength can be ensured for a larger range of the first wavelength and the possible uses of such a photodetector can be increased.

In embodiments, at least one of the optically absorbing intermediate layers is directly adjacent to a detection cell, that is to say to the photoactive layer or to one of the charge transport layers, if these are present, this detection cell, and consists of an electrically conductive material. It is also suitable for being connected in an electrically conductive manner to an evaluation unit which is suitable for evaluating the electrical signals generated by the at least one detection cell of the first optoelectronic component. Such an intermediate layer thus serves as an electrical contact for tapping the electrical signals from the detection cell, even if the photoactive layer or a corresponding charge transport layer, if present, of the relevant detection cell does not directly adjoin an electrically conductive mirror layer.

In further embodiments, at least one optically transparent contact layer is arranged in the first optical cavity, which is directly attached to a detection cell, that is to say the photoactive layer or, if present, to one of the charge transport layers of this Detection cell, adjoins and consists of an electrically conductive material. This contact layer is suitable for being connected in an electrically conductive manner to an evaluation unit which is suitable for evaluating the electrical signals generated by the at least one detection cell of the first optoelectronic component. It thus serves as an electrical contact to pick up the electrical signals from the detection cell, even if the photoactive layer or a corresponding charge transport layer, if present, of the relevant detection cell does not directly adjoin an electrically conductive mirror layer or an electrically conductive intermediate layer. It is optically transparent in particular for the resonance wavelength belonging to the first wavelength.

As materials for an optically absorbing intermediate layer, layers of organic small molecules, organic mixed layers or polymers, e.g. highly doped hole-conducting materials such as MeO-TPD: F6TCNNQ or PEDOT: PSS with quantum dots (QD) are used. If the optically absorbing intermediate layer is to be electrically conductive, metals such as Ag or metal mixtures such as Ag: Ca or conductive oxides such as indium tin oxide (ITO) or zinc oxide (ZnO) or aluminum-doped zinc oxide (AZO) can also be used. An optically transparent contact layer can also consist of the same materials. The optical and electrical properties of such an intermediate or contact layer can be adjusted via the thickness and the mixture of the materials. The thickness of the layers for metals is preferably in the range from 0.1 nm to 40 nm, more preferably in the range from 5 nm to 10 nm, while for polymers or oxides in the range from 20 nm to 100 nm, more preferably in the range from 30 nm to 60 nm, with small thicknesses associated with greater optical transparency

An optically absorbing layer in the context of this application, which is used as an optically absorbing intermediate layer, is understood to mean a layer which is suitable for absorbing so much energy of a specific electromagnetic wave that it is extinguished. Such a specific electromagnetic wave has a wavelength which is different from the resonance wavelength assigned to the first wavelength. For this purpose, the material of the optically absorbing layer can only be absorbent for wavelengths that are different from the resonance wavelength assigned to the first wavelength, while it is not absorbent for the resonance wavelength assigned to the first wavelength. However, such a specific wavelength dependency of the absorption coefficient is not given to a sufficient extent for adjacent resonance wavelengths for most materials, as a result of which a selection of the absorbed wavelengths is also made via the spatial arrangement of the absorbing layer within the optical cavity, as described above has been. Since it generally applies that the degree of absorption for an electromagnetic wave depends on the product of the absorption coefficient k of the material at the specific wavelength of the electromagnetic wave and the thickness d of the layer as well as the energy E of the electromagnetic wave in the area of the layer, this product has for a A wavelength that does not correspond to the resonance wavelength assigned to the first wavelength has a value greater than or equal to 1 · E (kd E> 1 E) according to the invention. A layer made of a material with a very high absorption coefficient k can thus be made very thin, while a layer made of a material with a comparatively low absorption coefficient k must be made correspondingly thicker in order to achieve the extinction of a specific electromagnetic wave. In contrast, in the context of this application, an optically transparent layer, which is used, for example, as a spacer layer or as an optically transparent contact layer, is understood to mean a layer that absorbs as little energy as possible from a specific electromagnetic wave and thus hardly or at least less than the photoactive layer influenced. Here, the specific electromagnetic wave is that which has the resonance wavelength assigned to the first wavelength. For this purpose, the product of the absorption coefficient k of the material at the wavelength of the specific electromagnetic wave and the thickness d of the layer as well as the energy E of the specific electromagnetic wave in the area of the layer has a value of less than 1 (k - d - E <1 - E). Thus, a layer made of a material with a very small absorption coefficient k can be made relatively thick, while a layer made of a material with a comparatively higher absorption coefficient k must be made correspondingly thinner in order to keep the influence of a specific electromagnetic wave low. Typical absorption coefficients for metals are, for example, in the range of greater than 0.5, while typical materials for the photoactive layers have absorption coefficients of less than 0.01. Typical materials for charge transport layers have absorption coefficients of less than 0.1.

If the electrical contact between the detection cell and the evaluation unit is established via such an intermediate layer or contact layer, the mirror layer then no longer required for the electrical contact can be optimized for its optical, ie reflective or semitransparent, properties. By decoupling the optical and electrical elements of the optoelectronic component, it is possible to improve the detection result by improving the optical properties of the mirror layers. In other embodiments, the first optoelectronic component has at least one external contact which is adjacent to an external surface of a detection cell, that is to say to an external surface of the photoactive layer or one of the charge transport layers, if present, and consists of an electrically conductive material. This external contact is suitable to be connected in an electrically conductive manner to an evaluation unit which is suitable for evaluating the electrical signals generated by the at least one detection cell of the first optoelectronic component. Such an external contact thus serves as an electrical contact for tapping the electrical signals from the relevant detection cell, even if the photoactive layer or a charge transport layer, if present, of this detection cell is not directly adjacent to an electrically conductive mirror layer or an electrically conductive intermediate layer or contact layer. In particular, metals such as Ag or Au are used as materials for such an external contact.

The first optoelectronic component preferably has at least two such external contacts which are arranged on opposite sides of the detection cell. The opposite sides are corresponding sides of the detection cell which are spaced from one another along the length of the optical cavity, for example a first side of the photoactive layer facing the first mirror layer and a second side of the photoactive layer facing the second mirror layer or the first charge transport layer and the second charge transport layer. Of course, the two external contacts must be electrically isolated from one another in each case. This means that external contacts that are directly adjacent to the photoactive layer can be used for thick photoactive layers and not for very thin photoactive layers.As in the embodiment with two external contacts in one detection cell, there are no additional electrically conductive layers that could optically influence the resonance wave in the Detection cell are present and at the same time the electrical contacting of the detection cell is decoupled from the mirror layers, the layers present in the optical cavity can be optimized for their optical properties. This enables the detection result to be further improved by improving the cavity quality.

In an optoelectronic component, various of the options described above for making electrical contact in a detection cell or for various detection cells can also be used.

In embodiments of the photodetector, at least one optically transparent spacer layer is arranged in the first optical cavity, the spacer layer between one of the mirror layers and a detection cell adjacent to this mirror layer is arranged. The optically transparent spacer layer is a layer which hardly influences at least the standing wave with the resonance wavelength assigned to the first wavelength, as has been described above. The material and the thickness of the spacer layer are selected according to the conditions described above, the thickness also depending on the thicknesses of the other layers present in the optical cavity and the length of the optical cavity.

If two or more detection cells are arranged in the first optical cavity, then in embodiments of the photodetector according to the invention an optically transparent spacer layer of the type described above is arranged between two detection cells arranged one above the other in the first optical cavity along the length of the first optical cavity.

The optically transparent spacer layers are preferably electrically non-conductive, i.e. electrically insulating, and preferably consist of transparent oxides such as Al ₂ O ₃ , S1O ₂ , T1O ₂ or organic compounds, such as are also used for the charge transport layers. These layers preferably have a charge carrier mobility of less than 10 ⁶ cm ² / Vs and therefore only a very low electrical conductivity. In this case, the electrical contact of the charge transport layer of a detection cell adjoining the spacer layer to the evaluation unit is established via an electrically conductive intermediate layer or contact layer or an external contact, as described above. The mirror layer then no longer required for the electrical contact and also the other layers within the optical cavity can thus be optimized independently of one another with regard to their optical or electrical properties. By decoupling the optical and electrical elements of the photodetector, it is possible to improve the detection result.

In embodiments, the photodetector contains a second optoelectronic component for detecting a second wavelength of the electromagnetic radiation. The second optoelectronic component has, similarly to the first optoelectronic component, a second optical cavity and at least one detection cell arranged in the second optical cavity. The second optical cavity is also formed by two parallel mirror layers that are spaced apart from one another, the length of the second optical cavity being configured such that a resonance wave j assigned to it is created for the second wavelength. Order in the second optical cavity forms. Each detection cell of the second optoelectronic component contains a photoactive layer. The photoactive layer is in each case within the second optical cavity arranged that an oscillation maximum of the resonance wave lies within the photoactive layer. In such a photodetector, the length of the first optical cavity differs from the length of the second optical cavity and / or the order of the resonance wave assigned to the second wavelength differs from the order of the resonance wave assigned to the first wavelength. The order of the resonance wave of the second optoelectronic component can also be the 1st order. At least one detection cell of the second optoelectronic component preferably also contains a first charge transport layer and a second charge transport layer, between which the photoactive layer is arranged. This means that the layers mentioned are arranged one above the other, that is to say adjoining one another, along the length of the second optical cavity.

In such a photodetector, the first and the second optoelectronic component can be arranged next to one another along a direction perpendicular to the length of the first and the second optical cavity. This arrangement is also referred to as a lateral arrangement. They can be spaced apart from one another and physically separated from one another, so that each optoelectronic component can be individually (separately) connected to an evaluation unit. The first and the second optoelectronic component can also be arranged adjacent to one another, but with electrical separation of the charge transport layers, if present, and / or the layers leading the electrical signals to the outside, such as mirror layers, intermediate layers or contact layers, of the optoelectronic components, that is, a pixelation of these layers is necessary. A predetermined lateral arrangement of different optoelectronic components can also be repeated one or more times in a direction perpendicular to the length of the optical cavities next to one another, i.e. laterally next to each other. An image-generating system, a so-called imager system, can thus be implemented.

In other embodiments of a photodetector with two optoelectronic components, the first and second optoelectronic components are arranged one above the other, so that the lengths of the first optical cavity and the second optical cavity extend along a common line. This arrangement is also referred to as a vertical arrangement. The first and the second optical cavity are connected to one another by a semi-transparent mirror layer, that is, the first optical cavity and the second optical cavity share this semi-transparent mirror layer, which serves as a mirror in each of the two optoelectronic components. resembles a stacking of optoelectronic components, on the one hand the active area of the photodetector can be reduced. On the other hand, this structure enables one photodetector that reacts selectively to certain angles of incidence of the incident electromagnetic radiation, in which an optoelectronic component with a large optical cavity length detects a defined wavelength or a defined wavelength range in the incident radiation at large angles of incidence, while an optoelectronic component with a smaller optical cavity length the same defined wavelength or the same defined wavelength range in the incident radiation is detected at small angles of incidence if both optoelectronic components are components of the same order. Of course, the different angle-dependent response behavior of the two optoelectronic components cannot be achieved, or not only over the length of the optical cavity, but also or additionally over different orders of the optoelectronic components.

A photodetector for spectrally selective detection of electromagnetic radiation according to a second aspect of the invention contains a first optoelectronic component for detecting a first wavelength of the electromagnetic radiation. The mere presence or absence of the first wavelength in the electromagnetic radiation incident on the photodetector (qualitative statement) and / or the intensity of the radiation of the first wavelength in the incident electromagnetic radiation (quantitative statement) can be detected. The first optoelectronic component has a first optical cavity, a detection cell arranged in the first optical cavity and at least one optically transparent spacer layer. The first optical cavity is formed by two parallel mirror layers that are spaced apart from one another, the length of the first optical cavity being configured such that a resonance wave i assigned to it is created for the first wavelength. Forms order in the first optical cavity. The above formula (1) applies, where i can be greater than or equal to 1.

The detection cell arranged in the first optical cavity contains a photoactive layer which preferably extends over the entire cross-sectional area of the first optical cavity, the cross-sectional area running perpendicular to the length of the first optical cavity. The photoactive layer of the detection cell is arranged within the first optical cavity in such a way that the oscillation maximum of the resonance wave lies within the photoactive layer. The photoactive layer is thus preferably arranged centrally in the first optical cavity with respect to its length.

The detection cell preferably furthermore has a first charge transport layer and a second charge transport layer, the photoactive layer between the first and the the second charge transport layer is arranged. The individual layers are arranged one above the other along the length of the first optical cavity. The first and second charge transport layers also preferably extend over the entire cross-sectional area of the first optical cavity, the first charge transport layer being adjacent to a first surface of the photoactive layer and the second charge transport layer being adjacent to a second surface of the photoactive layer and the second surface being opposite the first surface . The charge transport layers serve to improve the charge extraction from the photoactive layer and its conduction to electrical contacts, also called electrodes, which forward the electrical signals generated in the detection cell to an evaluation unit which is suitable for evaluating them. These charge transport layers can be made very thin, which means that they can also be referred to as injection or extraction layers. It does not always have to be doped layers.

The at least one optically transparent spacer layer is arranged between one of the mirror layers and the detection cell, that is, between the relevant mirror layer and the photoactive layer or between the relevant mirror layer and the charge transport layer of the detection cell adjacent to this mirror layer. With regard to its optical properties, the optically transparent spacer layer is designed as set out above and is also electrically insulating. This means that an electrical signal from the photoactive layer or the corresponding charge transport layer cannot be read out via the corresponding adjacent mirror layer, that is to say fed to an evaluation unit.

According to the invention, therefore, the first optoelectronic component of the photodetector according to the second aspect has at least one external contact that is connected to an external surface of the detection cell, that is to say the photoactive layer or the charge transport layer - if present - which is separated from the adjacent mirror layer by the at least one spacer layer The external contact consists of an electrically conductive material, as has already been described with regard to the photodetector according to the first aspect, and is suitable for being connected in an electrically conductive manner to an evaluation unit, the evaluation unit being suitable that of the detection cell to evaluate electrical signals generated by the first optoelectronic component.

Since there is no electrically conductive contact layer, which extends over large areas of the cross-sectional area of the first optical cavity, and the electrical Contact is instead relocated to the outer surface of the detection cell, the optical propagation of the resonance wave in the optical cavity is less disturbed, whereby the cavity quality of the first optical cavity is improved. In addition, the layers arranged in the optical path of the resonance wave can be optimized with regard to their materials for their optical properties. All of this contributes to improving the detection result.

In a preferred embodiment of the photodetector according to the second aspect, an optically transparent spacer layer, as already described, is arranged between each of the mirror layers and the detection cell, that is to say between the respective mirror layer and the photoactive layer or the charge transport layer of the detection cell adjacent to this mirror layer, and the first optoelectronic component has at least two external contacts, one external contact in each case adjoining the outer surface of the detection cell on a first side and adjoining the outer surface of the detection cell on a second side. The first side and the second side of the detection cell are opposite one another along the length of the first optical cavity. Each external contact is thus adjacent either to the outer surface of the photoactive layer on a first or second side of the detection cell or to an outer surface of the first charge transport layer or the second charge transport layer, if present.

A photodetector for spectrally selective detection of electromagnetic radiation according to a third aspect of the invention contains a first optoelectronic component for detecting a first wavelength of the electromagnetic radiation and a second optoelectronic component for detecting a second wavelength of the electromagnetic radiation. Here, too, the mere presence or absence of the first or the second wavelength in the electromagnetic radiation incident on the photodetector (qualitative statement) and / or the intensity of the radiation of the first or the second wavelength in the incident electromagnetic radiation (quantitative statement) can be detected .

The first optoelectronic component has a first optical cavity and at least one detection cell arranged in the first optical cavity. The first optical cavity is formed by two parallel mirror layers that are spaced apart from one another, the length of the first optical cavity being configured such that a resonance wave i assigned to it is created for the first wavelength. Forms order in the first optical cavity. The formula (1) already given above applies. Each detection cell arranged in the first optical cavity contains a photoactive layer, as has already been explained with reference to the photodetector according to the first aspect. The photoactive layer of a detection cell is arranged within the first optical cavity in such a way that exactly one oscillation maximum of the resonance wave i. Order lies within the photoactive layer. This also corresponds to the first optoelectronic component according to the first aspect. However, in contrast to the photodetector according to the first aspect, the resonance wave can also be a first-order resonance wave, ie i> 1.

The second optoelectronic component has a second optical cavity and at least one detection cell arranged in the second optical cavity. The second optical cavity is formed by two parallel mirror layers that are spaced apart from one another, the length of the second optical cavity being configured such that a resonance wave j assigned to this is for the first wavelength. Forms order in the first optical cavity. The above formula (1) applies, where i is replaced by j.

Each detection cell arranged in the second optical cavity contains a photoactive layer, as has already been explained with reference to the first optoelectronic component. The photoactive layer of a detection cell is arranged within the second optical cavity in such a way that exactly one oscillation maximum of the resonance wave j. Order lies within the photoactive layer. This also corresponds to the structure of the first optoelectronic component. Here, too, the resonance wave can be a first order or higher order resonance wave.

At least one detection cell of the first and / or the second optical cavity preferably furthermore has a first charge transport layer and a second charge transport layer, as has already been explained with reference to the photodetector according to the first aspect.

According to the invention, the length of the second optical cavity differs from the length of the first optical cavity and / or the order of the resonance wave assigned to the second wavelength differs from the order of the resonance wave assigned to the first wavelength. The resonance waves of both optoelectronic components can also be first order resonance waves. Furthermore, according to the invention, the first and the second optoelectronic component are arranged one on top of the other, so that the lengths of the first and the second optical cavity extend along a common line, the first and the second optical cavity passing through a semitransparent one Mirror layer, each of which is one of the mirror layers of the first optical cavity and the second optical cavity, are connected to one another.

With this structure, which is sufficient for a stack of optoelectronic components, on the one hand the active area of the photodetector can be reduced. On the other hand, this structure enables a photodetector that reacts selectively to certain angles of incidence of the incident electromagnetic radiation, in which an optoelectronic component with a large length of the optical cavity detects a defined wavelength in the incident radiation at large angles of incidence, while an optoelectronic component with a smaller length of the optical cavity detected the same defined wavelength in the incident radiation at small angles of incidence if both optoelectronic components are components of the same order. Of course, the different angle-dependent response behavior of the two optoelectronic components cannot be achieved, or not only over the length of the optical cavity, but also or additionally over different orders of the optoelectronic components.

The semi-transparent mirror layer that belongs to both optoelectronic components consists of one or more of the materials already mentioned in connection with the photodetector according to the first aspect, the thickness of the material in relation to the reflection of the first or the second wavelength and the transparency of the each other of the first or the second wavelength is set. If the semitransparent mirror layer serves as an electrical contact for reading out the electrical signals generated in at least one of the two optoelectronic components, then the semitransparent mirror layer is electrically conductive.

In embodiments, the number of detection cells arranged in the first optical cavity and / or in the second optical cavity corresponds to the order of the respective resonance wave.

In one or both optoelectronic components, as described with reference to the first optoelectronic component of the photodetector according to the first aspect, an optically transparent and electrically conductive contact layer or a spacer layer can be arranged between one of the mirror layers and a detection cell adjacent to this mirror layer. If one of the optoelectronic components is a component with an order greater than 1, an optically transparent spacer layer can also be arranged one above the other in the optical cavity of this optoelectronic component along the length of this optical cavity Detection cells or one or more optically absorbing intermediate layers can be formed.

Furthermore, at least one of the detection cells of the first optoelectronic component or of the second optoelectronic component can have at least one external contact that adjoins an external surface of the photoactive layer or one of the charge transport layers, consists of an electrically conductive material and is suitable, electrically connected to an evaluation unit to become, wherein the evaluation unit is suitable for evaluating the electrical signals generated by the detection cell. Here, too, the order of the resonance wave in the corresponding optoelectronic component is of no importance.

Of course, one or more further optoelectronic components can also be stacked over the first and the second optoelectronic component, a semitransparent mirror layer being arranged between adjacent optoelectronic components and belonging to both adjacent components.

The materials of the individual layers of the optoelectronic components of a photodetector according to the second or third aspect of the invention are the same as the materials mentioned with regard to the layers of the optoelectronic component of the photodetector according to the first aspect of the invention.

The photodetector according to each of the aspects of the invention can be formed on a substrate and surrounded by an enclosure or encapsulation as protection from environmental influences. In this case, however, at least the substrate or the housing must be transparent to the incident electromagnetic radiation, so that it can strike the photodetector.

For the purposes of the invention, the embodiments or individual features for designing the optoelectronic components and the photodetector can be combined with one another as long as they are not mutually exclusive.

In the following, the invention is to be illustrated with the aid of exemplary embodiments and figures. The dimensions of the individual elements and their relationship to one another are not true to scale, but only shown schematically. The same reference symbols designate corresponding components of the same type.

It show in longitudinal section, unless otherwise stated 1A shows a first embodiment of the photodetector according to the invention according to the first aspect of the invention, the optoelectronic component being a second order component and having two detection cells,

1B shows a second embodiment of the photodetector according to the invention according to the first aspect of the invention, the optoelectronic component being a second order component and having a detection cell,

1C shows a third embodiment of the photodetector according to the invention according to the first aspect of the invention, the optoelectronic component being a third-order component and having three detection cells,

2 shows a fourth embodiment of the photodetector according to the invention according to the first aspect of the invention, the optoelectronic component being a component of the 2nd order and having an optically absorbing intermediate layer,

3 shows a fifth embodiment of the photodetector according to the invention in accordance with the first aspect of the invention, the optoelectronic component being a second order component and having spacer layers and optically transparent and electrically conductive contact layers,

4A shows a sixth embodiment of the photodetector according to the invention according to the first aspect of the invention, wherein the optoelectronic component is a second order component and has spacer layers and electrical external contacts,

Fig. 4B is a plan view of a cross section through the photodetector of Fig. 4A along the line A-A ‘,

5A shows a seventh embodiment of the photodetector according to the invention according to the first aspect of the invention, the photodetector having two optoelectronic components which are arranged next to one another,

5B shows an eighth embodiment of the photodetector according to the invention according to the first aspect of the invention, the photodetector having two optoelectronic components which are arranged one above the other,

6A shows a first embodiment of the photodetector according to the invention according to the second aspect of the invention, wherein the optoelectronic component is a 1st order component and has external electrical contacts and optically transparent spacer layers,

6B shows a second embodiment of the photodetector according to the invention according to the second aspect of the invention, wherein the detection cell comprises charge transport layers, and

7 shows an embodiment of the photodetector according to the invention according to the third

Aspect of the invention, wherein the photodetector has two first-order optoelectronic components which are arranged one above the other.

Figures 1A to 5B show different embodiments of a photodetector according to the first aspect of the invention. It is characteristic of all embodiments according to the first aspect of the invention that at least one optoelectronic component is a component of the second or higher order.

FIG. 1A shows a first embodiment 1 of the photodetector according to the invention according to the first aspect of the invention. The photodetector 1 has an optoelectronic component 100 which is arranged between a transparent first substrate 201, for example made of glass or transparent plastic, and a second substrate 202. The second substrate 202 can also be transparent, but can also be opaque, semitransparent or reflective and can, for example, be an encapsulation made of glass, metal or plastic. The optical properties of the first and the second substrate 201, 202 relate to radiation with the first wavelength to be detected in the photodetector 1. Incident radiation 301 falls from a radiation source 300, which, for example, has a broad spectrum of wavelengths from UV light to infrared radiation, i.e. in the range from 100 nm to 50 pm, or only different wavelengths of a spectral range, e.g. of the infrared range from 780 nm to 50 μm, or can also contain only a single wavelength in one of these ranges, on the photodetector 1. The incident radiation 301 can, for example, radiation that is transmitted through a medium, e.g. a liquid, or which has passed through a medium, e.g. a solid body, or a radiation generated directly by the radiation source 300. As shown in FIG. 1A, the incident radiation 301 can enter the optoelectronic component 100 through the first substrate 201, but can also enter the optoelectronic component 100 through the second substrate 202 if the second substrate 202 is designed accordingly.

The optoelectronic component 100 has a semitransparent first mirror layer 11, which is arranged adjacent to the first substrate 201, and a second mirror layer 12, which is completely reflective and disposed adjacent to the second substrate 202. Both mirror layers 11, 12 consist, for example, of silver (Ag), the first mirror layer 11 having a smaller thickness, for example 27 nm, than the second mirror layer 12, which for example has a thickness of 100 nm. The first mirror layer 11 and the second mirror layer 12 are arranged parallel to one another at a distance L from one another and thus form an optical cavity between them. The length of the optical cavity, ie the distance L, and the thicknesses of the individual layers of the optoelectronic component 100 are each measured perpendicular to the parallel planes of the mirror layers 11 and 12. For specific first wavelengths of the incident radiation 301, standing resonance waves of different orders and corresponding resonance wavelengths are formed in the optical cavity according to the formula (1) already mentioned. As an example, a resonance wave 13 of the 2nd order is shown in FIG. 1A, the wavelength of which corresponds to the first wavelength to be detected in the photodetector 1 via the effective refractive index of the optical cavity and the layers present in the radiation path, for example the first substrate 201 and the first mirror layer 11 , connected is. In the optical cavity, that is to say between the mirror layers 11 and 12, two detection cells 21 and 22 for detecting the resonance wave are arranged. Each detection cell 21, 22 contains a photoactive layer 210 or 220, to which a first charge transport layer 21 1 or 221 on one side in relation to the length of the optical cavity and in each case on the other side in relation to the length of the optical cavity adjoin a second charge transport layer 212 or 222. The first charge transport layer 211 or 221 is, for example, a hole-conducting material, while the second charge transport layer 212 or 222 is an electron-conducting material. The photoactive layers 210, 220 consist, for example, of TPDP: C60 and have a thickness of 100 nm. The photoactive layers 210, 220 are each arranged within the optical cavity in such a way that in each case exactly one intensity maximum (also called the antinode) of the resonance wave 13 lies within one of the photoactive layers 210, 220. Since the resonance wave 13 detected by the optoelectronic component 100 is a second order wave, the optoelectronic component 100 is referred to as a second order component.

The first charge transport layer 211 of the first detection cell 21 adjoins the second mirror layer 12 and the second charge transport layer 222 of the second detection cell 22 adjoins the first mirror layer 11. In addition, the second charge transport layer 212 of the first detection cell 21 and the first charge transport layer 221 of the second detection cell 22 adjoin one another. The electrical signals generated in the detection cells 21 and 22 are generated by the Mirror layers 1 1 and 12, which are electrically conductive and electrically conductively connected to an evaluation unit, are forwarded, the evaluation unit being suitable for providing qualitative and / or quantitative information on the radiation of the first wavelength contained in the incident radiation 301 from the electrical signals to generate.

With reference to FIGS. 1 B and 1 C, the concept of order is to be explained further in relation to the optoelectronic component. Most of the following figures do not show the substrates or the radiation source.

1B shows an optoelectronic component 101 of a second embodiment 2 of the photodetector according to the first aspect of the invention. In contrast to the optoelectronic component 100 of FIG. 1A, only one detection cell 21 is arranged in the optical cavity of the optoelectronic component 101, which is formed as described with reference to FIG. 1A. Instead of the second detection cell 22 of the optoelectronic component 100 of FIG. 1A, an optically absorbing and electrically conductive intermediate layer 30 and an optically transparent spacer layer 40 are now arranged between the detection cell 21 and the first mirror layer 11. The photoactive layer 210 of the detection cell 21 is again arranged in exactly one intensity maximum of the resonance wave 13, which is again a resonance wave of the 2nd order, while the intermediate layer 30 is arranged in the middle node of the resonance wave 13. Since the intermediate layer 30 is designed to be optically absorbent, all further resonance waves that are in the optical cavity between the

In principle, mirror layers 11 and 12 would form and their nodes of oscillation are not in the intermediate layer 30, extinguished. Above all, the resonance waves of neighboring orders, i.e. the first and third order resonance waves, are extinguished.

In the case shown in Fig. 1B, the spacer layer 40 is made of a material which is not or only poorly electrically conductive, e.g. from AI2O3. The intermediate layer 30 therefore also serves as a contact layer for forwarding the electrical signals generated in the detection cells 21 to an evaluation unit and is made of an electrically conductive material, e.g. Ag: Ca, and formed with a thickness of, for example, 6 nm, the

Intermediate layer 30 is electrically conductively connected to the evaluation unit. For this purpose, the intermediate layer 30 is designed in such a way that it projects beyond the lateral edge of the other layers in the optical cavity and, for example, via clamps or others

Connecting elements, such as bonding wires, can be connected to an electrical line to the evaluation unit. If the material of the spacer layer is electrically conductive, the intermediate layer can also be designed to be absorbent and only slightly electrically conductive. In addition, the intermediate layer can be dispensed with entirely if the effect of extinguishing other resonance waves is not desired. In other embodiments, it is also possible to design the intermediate layer to be non-absorbent but electrically conductive, so that an electrical connection between the detection cell 21 and the evaluation unit is possible via the intermediate layer, but there is no cancellation of resonance waves.

Although the optoelectronic component 101 has only one detection cell 21, the optoelectronic component 101 is also a second-order component, since it detects and evaluates a second-order resonance wave.

1C shows an optoelectronic component 102 of a third embodiment 3 of the photodetector according to the first aspect of the invention. A 3rd order resonance wave 14 is detected here, so that the optoelectronic component 102 is a 3rd order component. The optoelectronic component 102 has three detection cells 21 to 23 which each contain a photoactive layer 210, 220 or 230 and two charge transport layers 21 1 and 212 or 221 and 222 or 231 and 232 and are arranged one above the other in the optical cavity. The photoactive layers 210, 220 and 230 are each arranged in the optical cavity in such a way that exactly one oscillation maximum of the resonance wave 14 lies in each of the photoactive layers 210, 220 and 230. Of course, the optoelectronic component 102 could also have only one or two detection cells, it still being a 3rd order component as long as the respective photoactive layers of the detection cells are each located at exactly one oscillation maximum of the resonance wave 14.

Further embodiments of the optoelectronic component of the photodetector according to the first aspect of the invention are described with reference to FIGS. 2 to 4B, components of the 2nd order being shown by way of example. For example, FIG. 2 shows an optoelectronic component 103 of a fourth embodiment 4 of the photodetector, the optoelectronic component 103 having two detection cells 21 and 22. An optically absorbing intermediate layer 31, which however is not electrically conductive, is arranged between the detection cells 21 and 22. However, the intermediate layer 31 must not hinder the charge transport if the individual detection cells 21 and 22 are not individually electrically contacted to the outside, as is shown in FIG. 2. In this case, the intermediate layer 31 is conductive for at least one type of charge carrier, that is to say electrons or holes, or for both. This can be achieved by making the intermediate layer 31 very thin. For example, the intermediate layer 31 can consist of a metal layer, for example Ag, or a mixed metal layer, for example Ag: Ca, with a thickness in the range from 1 nm to 5 nm. The intermediate layer 31 can also consist of a very thin, highly doped organic layer absorbing in the corresponding wavelength range of the resonance wave, e.g. BFDPB: NDP9 with a thickness of 1 nm.Alternatively, the intermediate layer 31 can also be in the form of a structured layer and have holes that transport charge allow from an adjacent layer to another adjacent layer, while the existing areas of the intermediate layer 31 lead to an extinction of the resonance waves of adjacent orders. The intermediate layer 31 serves to cancel out resonance waves of adjacent orders (adjacent to the order of the resonance wave 13). In order to avoid cancellation of the resonance wave 13, the intermediate layer 31 is arranged within the optical cavity at a point of the central node of the resonance wave 13 and is only thin, for example with a thickness in the range from 1 nm to 5 nm. As in the case of the optoelectronic component 100 of FIG. 1A, the connection to the evaluation unit is established via the electrically conductive mirror layers 11 and 12, but can also be implemented differently in other embodiments.

For optoelectronic components of a higher order which are designed to detect resonance waves of a higher order than the 2nd order, a plurality of optically absorbing intermediate layers are preferably formed. These are each arranged so that each node of the resonance wave lies in exactly one optically absorbing intermediate layer.

3 shows an optoelectronic component 104 of a fifth embodiment 5 of the photodetector, spacer layers 40 and electrically conductive, optically transparent contact layers 50 being arranged in the optical cavity of optoelectronic component 104 in addition to detection cells 21 and 22. The detection cells 21 and 22 are each spaced from each other and from the adjacent mirror layers 1 1 and 12 by the spacer layers 40. Since the spacer layers 40 are not or only poorly electrically conductive in the present case and therefore no electrical contact to the detection cells 21 and 22 via the Mirror layers 11 or 12 is possible, the electrical signals generated by the detection cells 21 and 22 are passed on via the contact layers 50 to the evaluation unit. For this purpose, the contact layers 50 are each adjacent to the first and second charge transport layers 21 1 and 212 or 221 and 222 and are arranged between these and the spacer layers 40 and can each be connected to the evaluation unit in an electrically conductive manner. The contact layers 50 are designed to be flat, ie they are each over the entire lateral Expansion of the charge transport layers 21 1, 212, 221 and 222 formed. Since the contact layers 50 are arranged in areas of the optical cavity in which the intensity of the resonance wave 13 does not have a node, but an intensity not equal to 0 (zero), the contact layers 50 must consist of an optically transparent material in order to cancel out the resonance wave 13 avoid. The contact layers 50 can, for example, consist of PEDOT: PSS, ITO, ZnO or other conductive oxides and each have a thickness of, for example, 10 nm to 40 nm. Here, too, the contact layers 50 protrude laterally over the other layers in the optical cavity in order to be able to realize an electrical connection to the evaluation unit, as has already been explained with reference to the intermediate layer 30 in FIG. 1B.

Another possibility of making electrical contact with the evaluation unit is shown in FIGS. 4A and 4B with reference to an optoelectronic component 105 of a sixth embodiment 6 of the photodetector. The optoelectronic component 105 differs from the optoelectronic component 104 from FIG. 3 in that there are no two-dimensional contact layers, but rather the electrical connection between the charge transport layers 21 1, 212, 221 and 222 takes place via electrical external contacts 60. The external contacts 60 consist of an electrically conductive material, for example Ag, and adjoin at least a part of the external surface of the charge transport layers 21 1, 212, 221 and 222. In this case, an outer surface of the charge transport layers 21 1, 212, 221 and 222 extends along the length of the optical cavity and does not adjoin another layer of the optoelectronic component 104, except for the external contacts 60. The external contacts 60 can also overlap with part of the charge transport layers 21 1, 212, 221 and 222, ie adjoin a surface of the charge transport layers 21 1, 212, 221 and 222 which extends or can extend parallel to the mirror layers 1 1, 12 also protrude into the charge transport layers 211, 212, 221 and 222. However, the external contacts 60 do not extend over the entire lateral extent of the charge transport layers 21 1, 212, 221 and 222. By pulling the external contacts into the optical cavity, the active area of the optoelectronic component, i.e. the area in which it is standing Waves can arise laterally, ie in a plane perpendicular to the length of the optical cavity, limited. In addition, the outer contacts can also serve as an optical aperture mask. The external contacts 60 thus hardly influence the optical formation or propagation of the resonance wave 13. The external contacts 60 preferably surround the charge transport layers 21 1, 212, 221 and 222 along the entire circumference of the external surface in cross section through the optoelectronic component, as shown in FIG. 4B is shown. FIG. 4B shows a cross section through the optoelectronic component 105 of FIG. 4A along the line AA ′. The electrical external contact 60 here forms a frame around the first charge transport layer 21 1. Electrical connection elements or connection lines to the evaluation unit can again engage the electrical external contacts 60, as has already been described with reference to FIG. 1B.

Of course, other combinations of the structures and layers of the optoelectronic component described in FIGS. 1A to 4B are also possible, with it being possible to optimize different layers with regard to their optical and / or electrical properties and to optimize the optoelectronic component with regard to its detection properties and / or its production .

Embodiments of the photodetector according to the first aspect of the invention are described with reference to FIGS. 5A and 5B, the photodetector each having two optoelectronic components which are suitable for detecting different wavelengths in the incident radiation. Of course, the number of optoelectronic components can be expanded as desired and both embodiments can also be combined with one another.

FIG. 5A shows a seventh embodiment 7 of the photodetector with two optoelectronic components 106 and 107, these being arranged laterally next to one another. That is to say, the optoelectronic components 106 and 107 are arranged next to one another along a direction which runs perpendicular to the lengths of the optical cavities of the two components 106 and 107. In the case shown, the two components 106 and 107 are arranged next to one another on the transparent first substrate 201 and are delimited from the environment by the second substrate 202 in the form of an encapsulation. The first optoelectronic component 106 has a first mirror layer 11a, a second mirror layer 12a and two detection cells 21a and 22a, the first optical cavity, which is formed between the mirror layers 11a and 12a _, having a length L _a . The second opto-electronic device 107 has a first mirror layer 11 b, a second mirror layer 12b and two detection cells 21 b and 22b, wherein the second optical cavity disposed between the mirror layers 11 b and 12b is formed, a length L _b has. Here, L _b <L _a in the illustrated case. Both optoelectronic components 106 and 107 are 2nd order components, with the same materials for the individual layers of components 106 and 107 the first optoelectronic component 106 having a first wavelength that corresponds to the first resonance wave 13a formed, and the second optoelectronic component 107 having a second wavelength, which corresponds to the formed second resonance wave 13b, can detect, wherein the first wavelength is greater than the second wavelength. However, in other embodiments, the optoelectronic components can also differ with regard to the order of the respective resonance wave with the same length of the optical cavity or with respect to the order of the respective resonance wave and the length of the optical cavity. The first mirror layers 11a and 11b and the second mirror layers 12a and 12b are used in the illustrated case to read out the electrical signals generated in the optoelectronic components 106 and 107 and are connected to an evaluation unit (not illustrated) in an electrically conductive manner. In other embodiments, the electrical signals can also be transmitted to the evaluation unit via the intermediate or contact layers or external contacts illustrated with reference to FIGS. 1B and 3 to 4B, wherein the detection cells can be electrically isolated from one or both mirror layers of the respective component . In this case, mirror layers of different optoelectronic components that are electrically isolated from an adjacent detection cell can also be formed jointly and connected to one another.

FIG. 5B shows an eighth embodiment 8 of the photodetector with two optoelectronic components 108 and 109, these being arranged one above the other. That is, the lengths of the first optical cavity and the second optical cavity of the optoelectronic components 108 and 109 extend along a common line, the first and the second optical cavity being connected to one another by a semitransparent mirror layer. In other words: the optoelectronic components 108 and 109 are stacked on top of one another so that the incident radiation does not reach one of the two optoelectronic components until it has passed through the other optoelectronic component. In the case shown, the incident radiation 301 only enters the optoelectronic component 109 after passing through the optoelectronic component 108.

The first optoelectronic component 108 has a semitransparent mirror layer 11, a semitransparent mirror layer 11 'and two detection cells 21a and 22a, the first optical cavity, which is formed between the mirror layers 11 and 11', having a length L _a . The second opto-electronic device 109 has the semi-transparent mirror layer 1 1 ', a second mirror layer 12, and two detection cells 21 b and 22b, wherein the second optical cavity disposed between the mirror layers 1 1' is formed and 12, a length L _b has. In the case shown, L _b <L _a . But L _b > L _a is also possible. Both optoelectronic components 108 and 109 are 2nd order components, With the same materials for the individual layers of the components 108 and 109, the first optoelectronic component 108 has a first wavelength that corresponds to the formed first resonance wave 13a, and the second optoelectronic component 109 has a second wavelength that corresponds to the formed second resonance wave 13b, can detect, wherein the first wavelength is greater than the second wavelength. However, in other embodiments, the optoelectronic components can also differ with respect to the order of the respective resonance wave with the same length of the optical cavity or with respect to the order of the respective resonance wave and the length of the optical cavity.

With the eighth embodiment 8 of the photodetector it is thus possible to detect two different wavelengths in the incident radiation 301 in a space-saving manner. One or more further optoelectronic components can also be stacked on top of one another, so that more than two different wavelengths can also be used with a photodetector, which only requires the lateral space of an optoelectronic component; can be detected.

In addition, with this embodiment it is possible to form a photodetector which reacts selectively to the angle of incidence α of the incident radiation 301. In this case, for example, the optoelectronic component 108 would detect the presence of the first wavelength belonging to the wavelength of the first resonance wave 13a in the incident radiation 301 at large angles of incidence a, while the optoelectronic component 109 would detect the presence of the first wavelength in the incident radiation 301 for small angles of incidence a detected via the detection of the associated second resonance wave 13b. The wavelengths of the first and second resonance waves 13a, 13b correspond to the first wavelength in the incident radiation 301 and the angle of incidence α.

In the illustrated case, the mirror layers 11, 11 ′ and 12 serve to read out the electrical signals generated in the optoelectronic components 108 and 109 and are connected to an evaluation unit (not illustrated) in an electrically conductive manner. In other embodiments, the electrical signals can also be transmitted to the evaluation unit via the intermediate or contact layers or external contacts illustrated with reference to FIGS. 1B and 3 to 4B, wherein the detection cells can be electrically isolated from one or both mirror layers of the respective component .

Of course, both embodiments explained with reference to FIGS. 5A and 5B can also be formed simultaneously in a photodetector, that is to say both different optoelectronic components can be arranged one above the other and next to one another. In addition, the optoelectronic components can also each be designed in accordance with one of the embodiments described with reference to Figures 1B and 2 to 4B, that is, they can be spacer layers, optically absorbent interlayers, optically absorbent and electrically conductive interlayers, optically transparent and electrically conductive contact layers and / or have electrical external contacts, wherein different optoelectronic components can be designed differently.

FIG. 6A shows a first embodiment 9 of the photodetector according to the invention according to the second aspect of the invention. According to the second aspect of the invention, the photodetector can also have only one first-order optoelectronic component. In FIG. 6A, this is the optoelectronic component 110, which has a semi-transparent first mirror layer 11 and a second mirror layer 12 as well as a detection cell 2T in the optical cavity present between these mirror layers 11, 12. The detection cell 21 ′ has a photoactive layer 210, but no charge transport layers. The photoactive layer 210 is arranged in the optical cavity in such a way that an oscillation maximum of the resonance wave 15, which is a resonance wave of the first order, lies within the photoactive layer 210. The photoactive layer 210 is separated from the mirror layers 11 and 12 by spacer layers 40 which are optically transparent and electrically insulating. The photoactive layer 210 can be connected to an evaluation unit via at least two electrical external contacts 60 ', similar to the external contacts 60 already explained with reference to FIGS. 4A and 4B, so that the electrical signals generated in the detection cell 21 can be read out. The external contacts 60 ′ consist of an electrically conductive material, for example Ag, and are adjacent to at least part of the external surface of the photoactive layer 210. Here, an outer surface of the photoactive layer 210 extends along the length of the optical cavity and does not adjoin another layer of the optoelectronic component 110, except for the external contacts 60 ′. The external contacts 60 ′ can also overlap with part of the photoactive layer 210, ie adjoin a surface of the photoactive layer 210 which extends parallel to the mirror layers 11, 12, or can also protrude into the photoactive layer 210. However, the external contacts 60 'do not extend over the entire lateral extent of the photoactive layer 210, but rather over a maximum of a small part, a maximum of 10% of the total lateral extent. The external contacts 60 ′ preferably surround the photoactive layer along the entire circumference of the external surface in cross section by the optoelectronic component, similar to that shown in FIG. 4B for the external contacts 60. In any case, one of the external contacts 60 ′ is arranged on a first side of the photoactive layer 210 and another of the external contacts 60 ′ is arranged on a second side of the photoactive layer 210, the first side and the second side being spaced from one another along the length of the optical cavity are and face each other. The first side of the first mirror layer 11 is closer, while the second side of the second mirror layer 12 is closer. The photoactive layer 210 is formed at least so thick that the external contact 60 ′ on the first side of the photoactive layer 210 is electrically separated, ie insulated, from the external contact 60 ′ on the second side of the photoactive layer 210. By separating the optical and electrical functions of the individual layers from one another, for example the reflective function of the mirror layers 11, 12 from an electrical conductivity to the outside, all components of the optoelectronic component 110 can be optimized either with regard to their optical or their electrical properties . By using the external contacts 60 ', optical losses within the optical cavity are further reduced and thus the quality and effectiveness of the detection of the photodetector are further improved.

FIG. 6B shows a second embodiment 9 'of the photodetector according to the invention according to the second aspect of the invention. The second embodiment 9 ′ is designed similarly to the first embodiment 9. However, in addition to a photoactive layer 210, the detection cell 21 of the optoelectronic component 1 10 'also has a first charge transport layer 21 1 and a second charge transport layer 212, similar to the previously described detection cells of a photodetector according to the first aspect. The charge transport layers 21 1 and 212 are of the to them adjacent mirror layers 1 1 and 12, respectively, spaced apart by spacer layers 40 which are optically transparent and electrically insulating. The charge transport layers 21 1 and 212 can each be connected to an evaluation unit via electrical external contacts 60, as already explained with reference to FIGS. 4A and 4B, so that the electrical signals generated in the detection cell 21 can be read out. The photoactive layer 210 in this embodiment can be made thinner than in the first embodiment 9. Here too, all components of the optoelectronic component 110 ′ can be optimized either with regard to their optical or their electrical properties. By using the external contacts 60, optical losses within the optical cavity are further reduced and thus the quality and effectiveness of the detection of the photodetector are further improved. FIG. 7 shows an embodiment 10 of the photodetector according to the invention according to the third aspect of the invention. According to the third aspect of the invention, the photodetector, similar to the eighth embodiment 8 of the photodetector according to the first aspect of the invention, has two optoelectronic components arranged one above the other, although both optoelectronic components can be components of the first order. Correspondingly, the photodetector 10 in the illustrated embodiment has two optoelectronic components 1 1 1 and 1 12, which are arranged one above the other so that the lengths of the optical cavities of both components 1 1 1 and 112 extend along a common line. The first optoelectronic component 111 has a semitransparent mirror layer 11 and a semitransparent mirror layer 11 'and a detection cell 21a arranged between them, the corresponding photoactive layer of the detection cell 21a being in the oscillation maximum of the resonance wave 15a, which is a first-order resonance wave . The optical cavity of the optoelectronic component

1 1 1 has a length L _a , which corresponds to a first wavelength to be detected in the incident radiation. The second optoelectronic component 11 has the semitransparent mirror layer 11 'and a mirror layer 12 as well as a detection cell 21b arranged in between, the corresponding photoactive layer of the detection cell 21b in the oscillation maximum of the resonance wave 15b, which is also a first-order resonance wave, lies. The optical cavity of the optoelectronic component

1 12 has a length L _b which corresponds to a second wavelength to be detected in the incident radiation and in the example shown is smaller than the length L _a . In other exemplary embodiments, however, L _{b can} also be greater than L _a .

As described with reference to FIG. 5B, the dependence of the wavelength of the resonance waves 15a, 15b on the angle of incidence of the incident radiation can also be used for an angle-selective detection of certain wavelengths in the incident radiation.

The two optoelectronic components 111 and 112 share the semitransparent mirror layer 11 '. In the embodiment shown, the mirror layers 11, 11 ′ and 12 serve to read out the electrical signals generated in the detection cells 21 a and 21 b and can be connected to an evaluation unit in an electrically conductive manner for this purpose. Of course, in other embodiments, other possibilities for establishing electrical contact with the charge transport layers of the detection cells, for example optically transparent and electrically conductive contact layers or electrical external contacts, as described above, can be implemented and / or Detection cells be spaced apart from adjacent mirror layers by spacer layers.

Within the meaning of the invention, the embodiments or individual features of the various aspects or embodiments for the configuration of the photodetector can also be combined with one another, as long as they are not mutually exclusive.

Various examples are described below which relate to what has been described and illustrated above.

Example 1 is a photodetector for the spectrally selective detection of electromagnetic radiation, with a first optoelectronic component for the detection of a first wavelength of the electromagnetic radiation, having: a first optical cavity, which is formed by two parallel mirror layers spaced apart, the length of the first optical The cavity is designed in such a way that a resonance wave i associated therewith is produced for the first wavelength. Forms order in the first optical cavity, and

at least one detection cell arranged in the first optical cavity, each detection cell containing a photoactive layer, the photoactive layer being arranged within the first optical cavity in such a way that exactly one oscillation maximum of the resonance wave lies within the photoactive layer, the order of the resonance wave of the first optoelectronic component is greater than 1.

Example 2 is a photodetector according to Example 1, wherein at least one detection cell arranged in the first optical cavity furthermore contains a first charge transport layer and a second charge transport layer, between which the photoactive layer is arranged, the first charge transport layer, the photoactive layer and the second charge transport layer are arranged one above the other along the length of the first optical cavity.

In example 3, the photodetector according to example 1 or 2 can have a number of the detection cells arranged in the first optical cavity which corresponds to the order of the resonance wave.

In example 4, in the photodetector according to one of examples 1 to 5, at least one optically absorbing intermediate layer is arranged in the first optical cavity in such a way that a node of the resonance wave lies in the absorbing intermediate layer. In example 5, in the photodetector according to example 4, at least one of the at least one optically absorbing intermediate layer is directly adjacent to one of the at least one detection cell, consists of an electrically conductive material and is suitable for being electrically conductive with an evaluation unit that is suitable for use by the to evaluate at least one detection cell of the first optoelectronic component generated electrical signals to be connected.

In example 6, in the photodetector according to one of examples 1 to 4, at least one optically transparent contact layer is arranged in the first optical cavity, which directly adjoins one of the at least one detection cell, consists of an electrically conductive material and is suitable, electrically conductive with a Evaluation unit which is suitable for evaluating the electrical signals generated by the at least one detection cell of the first optoelectronic component, to be connected.

In example 7, the first optoelectronic component of the photodetector according to one of examples 1 to 4 has at least one external contact which adjoins an external surface of one of the at least one detection cell, consists of an electrically conductive material and is suitable for being electrically conductive with an evaluation unit, which is suitable for evaluating the electrical signals generated by the at least one detection cell of the first optoelectronic component, to be connected.

In example 8, in the photodetector according to one of examples 1 to 7, at least one optically transparent spacer layer is arranged in the first optical cavity, said spacer layer being arranged between one of the mirror layers and a detection cell adjacent to this mirror layer.

In Example 9, at least two detection cells are arranged in the first optical cavity in a photodetector according to one of Examples 1 to 8, and an optically transparent spacer layer is arranged between two detection cells arranged one above the other in the first optical cavity along the length of the first optical cavity.

In example 10, a photodetector according to one of examples 1 to 9 contains a second optoelectronic component for detecting a second wavelength of the electromagnetic radiation, the second optoelectronic component having: a second optical cavity which is formed by two parallel mirror layers spaced apart from one another, the Length of the second optical cavity as it is designed that a resonance wave j associated therewith is produced for the second wavelength. Order in the second optical cavity, and • at least one detection cell arranged in the second optical cavity, each detection cell containing a photoactive layer, the photoactive layer being arranged within the second optical cavity in such a way that precisely one oscillation maximum of the resonance wave is within the photoactive layer lies.

The length of the first optical cavity differs from the length of the second optical cavity and / or the order of the resonance wave assigned to the second wavelength differs from the order of the resonance wave assigned to the first wavelength.

In an example 11, in the photodetector according to example 10, the first and the second optoelectronic component are arranged next to one another along a direction perpendicular to the length of the first and the second optical cavity

In an example 12, the first and second optoelectronic components (108, 109) are arranged one above the other in the photodetector according to example 10, so that the lengths of the first optical cavity and the second optical cavity extend along a common line, the first and the second optical cavity are connected to one another by a semi-transparent mirror layer.

Example 13 is a photodetector for the spectrally selective detection of electromagnetic radiation, with a first optoelectronic component for the detection of a first wavelength of the electromagnetic radiation, having: a first optical cavity, which is formed by two parallel mirror layers spaced apart, the length of the first optical The cavity is designed in such a way that a first-order resonance wave assigned to the first wavelength is formed in the first optical cavity,

a detection cell which is arranged in the first optical cavity and contains a photoactive layer, the photoactive layer being arranged within the first optical cavity such that the oscillation maximum of the resonance wave lies within the photoactive layer, and

at least one optically transparent spacer layer; which is arranged in the first optical cavity between one of the mirror layers and the detection cell, wherein the first optoelectronic component has at least one external contact which adjoins an outer surface of the detection cell, consists of an electrically conductive material and is suitable, electrically conductive with an evaluation unit which is suitable for the electrical signals generated by the detection cell of the first optoelectronic component to evaluate, to be connected.

In an example 14, the detection cell of the photodetector according to example 13 arranged in the first optical cavity further contains a first charge transport layer and a second charge transport layer, between which the photoactive layer is arranged, the first charge transport layer, the photoactive layer and the second charge transport layer along one another the length of the first optical cavity are arranged.

In an example 15, two optically transparent spacer layers are arranged in the first optical cavity in the photodetector according to one of examples 13 or 14, of which a first spacer layer is arranged between a first of the mirror layers and the detection cell and of which a second spacer layer is arranged between a second the mirror layers and the detection cell is arranged. In addition, the first optoelectronic component of the photodetector according to Example 15 has at least two external contacts, with one external contact each adjoining the outer surface of the detection cell on a first side and the outer surface of the detection cell on a second side, the first side and the opposite the second side of the detection cell along the length of the first optical cavity.

Example 16 is a photodetector for the spectrally selective detection of electromagnetic radiation, with a first optoelectronic component for the detection of a first wavelength of the electromagnetic radiation, having:

A first optical cavity, which is formed by two parallel mirror layers spaced apart from one another, the length of the first optical cavity being configured such that a resonance wave i assigned to this is for the first wavelength. Forms order in the first optical cavity, and

• at least one detection cell arranged in the first optical cavity, each detection cell containing a photoactive layer, the photoactive layer being arranged within the first optical cavity in such a way that exactly one oscillation maximum of the resonance wave lies within the photoactive layer, and a second optoelectronic component for detecting a second wavelength of the electromagnetic radiation, comprising:

A second optical cavity, which is formed by two parallel mirror layers spaced apart from one another, the length of the second optical cavity being configured such that a resonance wave j assigned to the second wavelength occurs. Order in the second optical cavity forms, and

• at least one detection cell arranged in the second optical cavity, each detection cell containing a photoactive layer, the photoactive layer being arranged within the second optical cavity in such a way that exactly one oscillation maximum of the resonance wave lies within the photoactive layer,

wherein the length of the second optical cavity differs from the length of the first optical cavity and / or the order of the resonance wave assigned to the second wavelength differs from the order of the resonance wave assigned to the first wavelength and the first and the second optoelectronic components are arranged one above the other, so that the lengths of the first and the second optical cavity extend along a common line, the first and the second optical cavity being connected to one another by a semitransparent mirror layer, which is in each case one of the mirror layers of the first optical cavity and the second optical cavity.

In example 17, at least one detection cell of the photodetector according to example 16 arranged in the first optical cavity or in the second optical cavity furthermore contains a first charge transport layer and a second charge transport layer, between which the photoactive layer is arranged, the first charge transport layer, the photoactive Layer and the second charge transport layer are arranged one above the other along the length of the first optical cavity or the second optical cavity.

In example 18, the number of detection cells of the photodetector according to example 16 or 17 arranged in the first optical cavity and / or in the second optical cavity corresponds to the order of the respective resonance wave. Reference number

1-8 photodetector according to the first aspect of the invention

9, 9 ‘photodetector according to the second aspect of the invention

10 photodetector according to the third aspect of the invention

100-1 12, 1 10 ‘Optoelectronic component

11, 11a, 11b First mirror layer

1 r Semi-transparent mirror layer

12, 12a, 12b Second mirror layer

13, 13a, 13b 2nd order resonance wave

14 3rd order resonance wave

15, 15a, 15b 1st order resonance wave

21, 21a, 21 b, 21 ‘, detection cell

22, 22a, 22b, 23

210, 220, 230 Photoactive layer

211, 221, 231 First charge transport layer

212, 222, 232 Second charge transport layer

30 Optically absorbing, electrically conductive intermediate layer

31 Optically absorbing intermediate layer

40 spacer layer

50 Optically transparent, electrically conductive contact layer

60, 60 ‘Electrical external contact

201 First substrate

202 Second substrate

300 radiation source

301 Incident Radiation

L Length of the optical cavity

La length of the first optical cavity

L _b length of the second optical cavity

a Angle of incidence of the incident radiation

Claims

1. Photodetector (1-8) for spectrally selective detection of electromagnetic radiation, with a first optoelectronic component (100-106, 108) for detecting a first wavelength of the electromagnetic radiation having:

a first optical cavity which is formed by two parallel mirror layers (11, 11a, 11 ', 12, 12a) which are spaced apart from one another, the length (L, L _a ) of the first optical cavity being designed so that for the first wavelength a resonance wave assigned to this i. Order (13, 13a) forms in the first optical cavity, and

at least one detection cell (21, 21a, 22, 22a, 23) arranged in the first optical cavity, each detection cell (21, 21a, 22, 22a, 23) containing a photoactive layer (210, 220, 230), the photoactive Layer (210, 220, 230) is arranged within the first optical cavity in such a way that exactly one oscillation maximum of the resonance wave (13, 13a) lies within the photoactive layer (210, 220, 230),

wherein the order of the resonance wave (13, 13a) of the first optoelectronic component (100-106, 108) is greater than 1,

characterized in that

at least one optically absorbing intermediate layer (30, 31) is arranged in the first optical cavity in such a way that a node of the resonance wave (13) lies in the absorbing intermediate layer (30, 31), the absorbing intermediate layer (30, 31) being suitable to absorb enough energy of a specific electromagnetic wave within the first optical cavity that it is extinguished, the specific electromagnetic wave having a wavelength different from the resonance wavelength assigned to the first wavelength, and / or

In the first optical cavity at least one optically transparent contact layer (50) is arranged, which directly adjoins one of the at least one detection cells (21, 22), consists of an electrically conductive material and is suitable, electrically conductive with an evaluation unit that is suitable to evaluate the electrical signals generated by the at least one detection cell of the first optoelectronic component (104), to be connected.

2. Photodetector (1-8) according to claim 1, characterized in that at least one detection cell (21, 21a, 22, 22a, 23) arranged in the first optical cavity continues a first charge transport layer (211, 221, 231) and a second

Contains charge transport layer (212, 222, 232), between which the photoactive layer (210, 220, 230) is arranged, wherein the first charge transport layer (211, 221, 231), the photoactive layer (210, 220, 230) and the second Charge transport layers (212, 222, 232) are arranged one above the other along the length of the first optical cavity.

3. Photodetector (1, 3-8) according to claim 1 or 2, characterized in that the number of the detection cells (21, 21a, 22, 22a, 23) arranged in the first optical cavity of the order of the resonance wave (13, 13a) corresponds.

4. Photodetector (2) according to one of the preceding claims, characterized in that at least one optically absorbing intermediate layer (30) is arranged in the first optical cavity and at least one of the at least one optically absorbing intermediate layer (30) directly to one of the at least one detection cell (21) is made of an electrically conductive material and is suitable for being connected in an electrically conductive manner to an evaluation unit which is suitable for evaluating the electrical signals generated by the at least one detection cell (21) of the first optoelectronic component (101).

5. photodetector (6) according to any one of the preceding claims, characterized in that the first optoelectronic component (105) has at least one external contact (60) which adjoins an outer surface of one of the at least one detection cell (21, 22), from one electrically conductive material and is suitable to be connected in an electrically conductive manner to an evaluation unit which is suitable for evaluating the electrical signals generated by the at least one detection cell of the first optoelectronic component (105).

6. photodetector (2, 5, 6) according to any one of the preceding claims, characterized in that at least one optically transparent spacer layer (40) is arranged in the first optical cavity, which between one of the mirror layers (11, 11a, 11 ', 12 , 12a) and a detection cell (21, 22) adjacent to this mirror layer (11, 11a, 11 ', 12, 12a).

7. Photodetector (5, 6) according to one of the preceding claims, characterized in that at least two detection cells (21, 22) are arranged in the first optical cavity and an optically transparent spacer layer (40) is arranged between two detection cells (21, 22) arranged one above the other in the first optical cavity along the length of the first optical cavity.

8. photodetector (7, 8) according to any one of the preceding claims, characterized in that

the photodetector (7, 8) contains a second optoelectronic component (107, 109) for detecting a second wavelength of the electromagnetic radiation, the second optoelectronic component (107, 109) having:

• a second optical cavity, which is formed by two parallel mirror layers (11 b, 12 b, 11 ‘, 12) spaced apart from one another, the length of the second optical cavity being designed such that a resonance wave j assigned to it is for the second wavelength. Order (13b) in the second optical cavity forms, and

• at least one detection cell (21b, 22b) arranged in the second optical cavity, each detection cell (21b, 22b) containing a photoactive layer (210, 220), the photoactive layer (210, 220) in each case within the second optical Cavity is arranged that exactly one oscillation maximum of the resonance wave (13b) lies within the photoactive layer (210, 220), and the length (L _a ) of the first optical cavity from the length (L _b ) of the second optical cavity and / or differs the order of the resonance wave (13b) assigned to the second wavelength from the order of the resonance wave (13a) assigned to the first wavelength.

9. photodetector (7) according to claim 8, characterized in that the first and the second optoelectronic component (106, 107) are arranged side by side along a direction perpendicular to the length (L _a , L _b ) of the first and the second optical cavity.

10. photodetector (8) according to claim 8, characterized in that the first and the second optoelectronic component (108, 109) are arranged one above the other, so that the lengths (L _a , L _b ) of the first optical cavity and the second optical Cavity extend along a common line, the first and the second optical cavity being connected to one another by a semi-transparent mirror layer (11 ').

11. A photodetector (9, 9 ‘) for the spectrally selective detection of electromagnetic radiation, with a first optoelectronic component (110, 110‘) for detecting a first wavelength of the electromagnetic radiation having:

a first optical cavity which is formed by two parallel mirror layers (11, 12) spaced apart from one another, the length of the first optical cavity being designed such that a resonance wave i. Order (15) forms in the first optical cavity, the order of the resonance wave being greater than or equal to 1,

a detection cell (21, 21 ') which is arranged in the first optical cavity and contains a photoactive layer (210), the photoactive layer (210) being arranged within the first optical cavity in such a way that the oscillation maximum of the resonance wave (15) is within the photoactive layer (210) lies, and

at least one optically transparent spacer layer (40) which is arranged in the first optical cavity between one of the mirror layers (11, 12) and the detection cell (21, 21 ‘),

characterized in that the first optoelectronic component (110, 110 ') has at least one external contact (60, 60') which adjoins an external surface of the detection cell (21, 21 '), consists of an electrically conductive material and is suitable, to be electrically connected to an evaluation unit which is suitable for evaluating the electrical signals generated by the detection cell (21, 21 ') of the first optoelectronic component (110, 110').

12. The photodetector (9 ') according to claim 11, characterized in that the detection cell (21) arranged in the first optical cavity further contains a first charge transport layer (211) and a second charge transport layer (212), between which the photoactive layer (210) is arranged, wherein the first charge transport layer (211), the photoactive layer (210) and the second charge transport layer (212) are arranged one above the other along the length of the first optical cavity.

13. photodetector (9, 9 ‘) according to claim 11 or 12, characterized in that

two optically transparent spacer layers (40) are arranged in the first optical cavity, of which a first spacer layer (40) is arranged between a first of the mirror layers (11, 12) and the detection cell (21, 21 ') and of which a second spacer layer (40) is arranged between a second of the mirror layers (11, 12) and the detection cell (21, 21 '), and the first optoelectronic component (110, 110 ') has at least two external contacts (60, 60'), one external contact (60, 60 ') to the outer surface of the detection cell (21, 21') on a first side and to the outer surface of the detection cell (21, 21 ') adjoins on a second side, the first side and the second side of the detection cell (21, 21') being opposite one another along the length of the first optical cavity.

14. Photodetector (10) for spectrally selective detection of electromagnetic radiation, with:

a first optoelectronic component (111) for detecting a first wavelength of the electromagnetic radiation having:

• a first optical cavity, which is formed by two parallel mirror layers (11, 11 ') spaced apart from one another, the length (L _a ) of the first optical cavity being designed such that a resonance wave i assigned to this is for the first wavelength. Order (15a) forms in the first optical cavity, and

• at least one detection cell (21a) arranged in the first optical cavity, each detection cell (21a) containing a photoactive layer (210), the photoactive layer (210) being arranged within the first optical cavity in such a way that exactly one oscillation maximum of the Resonance wave (15a) lies within the photoactive layer (210),

and

a second optoelectronic component (112) for detecting a second wavelength of the electromagnetic radiation having:

A second optical cavity, which is formed by two parallel mirror layers (11 ', 12) spaced apart from one another, the length (L _b ) of the second optical cavity being designed such that a resonance wave j assigned to this is for the second wavelength. Order (15b) forms in the second optical cavity, and

• at least one detection cell (21b) arranged in the second optical cavity, each detection cell (21b) containing a photoactive layer (210), the photoactive layer (210) being arranged within the second optical cavity in such a way that exactly one oscillation maximum of Resonance wave (15b) lies within the photoactive layer (210),

characterized in that the length (L _b ) of the second optical cavity differs from the length (L _a ) of the first optical cavity and / or the order of the resonance wave (15b) assigned to the second wavelength differs from the order of the resonance wave (15a) assigned to the first wavelength and

the first and the second optoelectronic component (111, 112) are arranged one above the other, so that the lengths (L _a , L _b ) of the first and the second optical cavity extend along a common line, the first and the second optical cavity through a semitransparent mirror layer (11 '), each of which is one of the mirror layers of the first optical cavity and the second optical cavity, are connected to one another.

15. The photodetector (10) according to claim 14, characterized in that at least one detection cell (21a, 21b) arranged in the first optical cavity or in the second optical cavity further contains a first charge transport layer (211) and a second charge transport layer (212) , between which the photoactive layer (210) is arranged, wherein the first charge transport layer (211), the photoactive layer (210) and the second charge transport layer (212) one above the other along the length (L _a , L _b ) of the first optical cavity or the second optical cavity are arranged.

16. The photodetector (10) according to claim 14 or 15, characterized in that the number of detection cells (21a, 21b) arranged in the first optical cavity and / or in the second optical cavity corresponds to the order of the respective resonance wave (15a, 15b) .