WO2006128407A1

WO2006128407A1 - Detector array and method for identifying spectral portions in radiation incident upon a detector array

Info

Publication number: WO2006128407A1
Application number: PCT/DE2006/000447
Authority: WO
Inventors: Arndt Jaeger; Peter Stauss
Original assignee: Osram Opto Semiconductors Gmbh
Priority date: 2005-05-30
Filing date: 2006-03-14
Publication date: 2006-12-07
Also published as: TW200707777A; DE102005043918A1; DE102005043918B4; TWI303106B

Abstract

The invention relates to a detector array (10) with a number of discrete radiation detectors (1, 2, 3) of which a first radiation detector and a second radiation detector of the detector array each have a semiconductor body (11, 21, 31) with an active region (12, 22, 32), which is provided for receiving radiation and generating signals, and each have a detection region assigned to the respective radiation detector. The semiconductor body, particularly the active region, of at least one radiation detector contains a III-V semiconducting material and/or the active region of the first radiation detector is provided with a design different from that of the second radiation detector. A detector array of the aforementioned type is particularly suited for detecting radiation in varicolored spectral regions.

Description

description

Detector arrangement and method for determining spectral components in a radiation incident on a detector arrangement

The invention relates to a detector arrangement having a plurality of radiation detectors and to a method for determining spectral components from a radiation incident on a detector arrangement.

For radiation detection in different wavelength ranges, a detector arrangement with a plurality of juxtaposed Si photodiode chips for radiation detection is often used. The spectral sensitivity distribution of the respective Si photodiode chip is adapted to the desired detection range via external filters assigned via the individual Si photodiode chips. Such a detector arrangement with a plurality of Si photodiode elements is known from the preliminary data sheet for the component "MTCSiCT" from Laser Components. However, this component is relatively expensive due to the complex dielectric filtering.

Si photodiode chips furthermore usually have their maximum sensitivity in the infrared spectral range. In the visible spectral range, however, Si photodiode chips generally generate a comparatively low signal, so that radiation detection by means of Si photodiode chips in the visible spectral range is ineffective compared to detection in the infrared spectral range.

An object of the present invention is to specify an improved detector arrangement, in particular for the efficient detection of radiation in the visible spectral range. Furthermore, it is an object of the invention to provide a method for determining spectral components in an incident on an efficient detector array radiation that the - -

Determination of the spectral components by means of inexpensive manufacturable radiation detectors allows.

This object is achieved by a detector arrangement with the features of claim 1 and by a method having the features of claim 18. Advantageous developments and refinements of the invention are the subject of the dependent claims.

A detector arrangement according to the invention comprises a plurality of discrete radiation detectors, in particular arranged laterally side by side, wherein a first radiation detector and a second radiation detector of the detector arrangement each have a semiconductor body with an active area provided for radiation reception and signal generation and one detection area associated with the respective radiation detector.

In this case, the detection region is preferably a, in particular contiguous, wavelength range in which the respective radiation detector is sensitive, that is to say in which a significant signal, which is visibly contrasted by a background noise, is generated by the respective radiation detector.

Expediently, the detection range lies in a wavelength range for which the detector arrangement or the respective radiation detector is provided for radiation detection. The respective radiation detector can be designed specifically for detection in a predetermined detection area.

In the invention, the semiconductor body, in particular the active area, at least one radiation detector, in particular the active area of the first radiation detector and the active area of the second radiation detector, contains a III-V semiconductor material and / or it is the active area of the first radiation detector of the active one Area of the second radiation detector performed differently. _ -

Radiation entering the semiconductor body from a radiation entrance side, which the semiconductor body of a radiation detector of the detector arrangement expediently has, strikes the active region of this radiation detector. If the incident radiation contains wavelengths for which the radiation detector is sensitive, then a corresponding proportion of the radiation power is absorbed in the semiconductor body, in particular the active region, of the radiation detector. The electron-hole pairs subsequently generated in the active region contribute to the signal of the radiation detector.

By means of a III-V semiconductor material in the signal-generating active region, particularly in the visible spectral range, an advantageously high internal quantum efficiency in the generation of electron-hole pairs due to photons striking the active region can be achieved. A high internal quantum efficiency is usually accompanied by an advantageously increased efficiency of the radiation detector.

Various embodiments of the active regions of the first and second radiation detectors facilitate the matching of the detection regions of the respective radiation detectors for radiation detection in different spectral ranges. A discrete and separate, that is not monolithically integrated, embodiment of the radiation detectors of the detector arrangement, the production cost can be reduced with advantage. Due to the separate embodiment, individual radiation detectors of the detector arrangement, in particular their semiconductor body, can be manufactured in a coordinated manner to a predetermined detection area assigned to the respective radiation detector.

In a preferred embodiment, a band gap and / or a thickness of a functional layer of the active region of the first radiation detector is different from a band gap or a thickness of a functional layer of the active region of the second radiation detector. The formation of a detector array .with radiation detectors for various , -

Detection areas can be facilitated.

About the band gap of the functional splitter, the detection range can be selectively influenced or shaped. The functional layer preferably absorbs substantially radiation in a wavelength range which comprises wavelengths smaller than the wavelength corresponding to the band gap of the functional layer.

The thickness of the functional layer determines the proportion of radiant power absorbed in the functional layer from the radiation incident on the detector array. By way of this, the strength of the detector signal, for example the photocurrent or variables derived therefrom, of the respective radiation detector can be set in a targeted manner. An increase in the thickness of the functional layer usually results in an increase in the radiation power absorbed therein, which in turn usually yields higher signals.

In a further preferred refinement, the wavelength corresponding to the band gap of the functional layer of the active region of the first radiation detector and / or the wavelength corresponding to the band gap of the functional layer of the active region of the second radiation detector lies in the visible spectral range. The formation of a detector arrangement for the efficient detection of radiation or for determining a spectral component in the visible spectral range is facilitated in the sequence.

It should be noted that in this case the spectral range which is considered to be the wavelength range in which the human eye, in particular light-adapted or dark-adapted, is sensitive according to the CIE eye sensitivity curve (CIE: Commission Internationale de l'Eclairage). In doubt, the wavelength range between 420 nm inclusive and 700 nm inclusive can be regarded as a visible ^■ spectral range, in particular for the light-adapted human eye. In a further preferred refinement, the wavelength corresponding to the band gap of the functional layer of the active region of the first radiation detector and the wavelength corresponding to the band gap of the puncturing layer of the active region of the second radiation detector lie in different-colored spectral regions. The detection or determination of different colored spectral components in an incident on the detector array radiation is facilitated. The detector arrangement can be provided or designed in particular for the detection of spectral components of different colors, for example, portions of the primary colors red, green and blue.

In a further preferred embodiment, the detection range of the first radiation detector and the detection range of the second radiation detector overlap, in particular only partially or completely. The detection of radiation over a coherent wavelength range, such as the visible spectral range, is facilitated. The detector arrangement is preferably arranged over a coherent, in particular predetermined, detection wavelength range, e.g. over the visible spectral range, sensitive. The detection wavelength range may be formed by means of the overlapping detection ranges of the individual radiation detectors.

In a further preferred refinement, the first and / or the second radiation detector has a predetermined spectral sensitivity distribution assigned to the respective radiation detector with one, local or global, maximum at a predetermined maximum wavelength.

For the spectral sensitivity distribution of a radiation detector, the dependence of the signal generated in the active region of this radiation detector (for example, the photocurrent or the quantities derived therefrom) on the wavelength of the radiation incident on the radiation detector is decisive here. - -

The maximum wavelength and / or the wavelength corresponding to the band gap of the functional layer of the active region of the radiation detector preferably lies in the detection region assigned to this radiation detector.

The generation of a comparatively high detector signal in the detection range of the radiation detector can thus be achieved in a simplified manner. In particular, this is to be seen in contrast to comparatively inefficient detectors whose band gap or sensitivity maximum lies outside the detection range, as is often the case, for example, in the case of detection in the visible spectral range with conventional Si photodiode chips.

In a further preferred embodiment of the detector arrangement, at least one radiation detector, in particular a plurality of radiation detectors, of the detector arrangement has a filter layer structure with at least one filter layer. Preferably, the filter layer structure is monolithically integrated in the semiconductor body of the radiation detector. In the filter layer structure, it is possible to absorb fractions from the incident radiation which do not reach the active region of the radiation detector for signal generation. Expediently, the filter layer structure is arranged and / or formed between a radiation entrance side of the radiation detector, in particular a radiation entrance side of the semiconductor body of this radiation detector, and the active region of the semiconductor body. The filter layer structures of radiation detectors for different detection areas are furthermore expediently designed differently from one another.

Furthermore, the filter layer structure preferably absorbs radiation in a wavelength range which has wavelengths smaller than the maximum wavelength of the spectral sensitivity distribution of the radiation detector and / or wavelengths smaller than the wavelength corresponding to the band gap of the functional layer of the active region of the radiation detector. - -

By means of the filter layer structure, the spectral sensitivity distribution of the radiation detector or the detection range of the radiation detector, in particular on the short wavelength side for wavelengths smaller than the Maxitnumswellenlänge and / or the band gap of the functional layer of the radiation detector corresponding wavelength can be selectively formed. The filter layer structure can determine a short-wave cut-off wavelength of the spectral sensitivity distribution of the radiation detector and / or a short-wave cutoff wavelength of the detection range of the radiation detector. Radiation absorbed in the filter layer structure does not reach the active region, so that only a correspondingly reduced signal is generated in the absorption wavelength range of the filter layer structure. A band gap of the filter layer determines the absorption wavelength range of the filter layer and a thickness of the filter layer determines the proportion of radiant power absorbed from the incident radiation.

In an advantageous development, two radiation detectors of the detector arrangement are designed such that a composition of a filter layer of the filter layer structure of one radiation detector is equal to the composition of the functional layer of the active region of the other radiation detector of the detector arrangement. In this case, the other radiation detector preferably has a detection region which comprises wavelengths smaller than the wavelength of the band gap of the wavelength corresponding to one radiation detector. The coordination of the detection areas of the two radiation detectors of the detector arrangement to one another such that a comparatively small overlap of their detection areas and / or their sensitivity distributions results can thus be facilitated. Particularly preferably, the filter layer of the one radiation detector has a thickness that is equal to the thickness of the functional layer of the other radiation detector. The formation of the individual radiation detectors for the detector arrangement and their coordination with each other can be further facilitated. - -

In a further preferred embodiment, the filter layer structure has a plurality of filter layers. The filter layers of the filter layer structure can be designed, for example, to absorb radiation having wavelengths from different wavelength ranges, so that the targeted shaping of the spectral sensitivity distribution of a radiation detector, in particular for wavelengths smaller than the maximum wavelength, can be simplified. For this purpose, the filter layers of the filter layer structure preferably have different band gaps and / or thicknesses for this purpose. The absorption wavelength range of the filter layer structure can thus be more favorably influenced or widened than a structure having a single filter layer in this way.

In a further preferred embodiment, two radiation detectors of the detector arrangement are designed such that the detection range of one radiation detector includes the wavelength corresponding to the band gap of the functional layer of the other radiation detector.

Preferably, the detection range of the other radiation detector has wavelengths outside of

Detection range of a radiation detector on. Preferably, the other radiation detector is provided as compared to the one longer wavelength radiation detector. The other radiation detector thus generates signals both in the detection area assigned to it and in the detection area of the one radiation detector. Although the determination of spectral components is thus made more difficult, the radiation detectors can advantageously be manufactured at lower cost. In particular, it is possible to dispense with a filter layer structure. Optionally, the maximum wavelength of the other radiation detector may be within the detection range of the one radiation detector.

In a further preferred embodiment, two radiation detectors of the detector arrangement are designed such that the band gap of the functional layer of the one - -

Radiation detector corresponding wavelength is outside the detection range of the other radiation detector.

This can be achieved by providing a suitable filter layer structure, such as the above-mentioned type, optionally in combination with a suitable formation of the active region. This facilitates the determination of spectral components in the incident radiation, since a spectral component can be assigned to a single radiation detector in a simplified manner. In particular, spectral components that are simplified in this way can be determined directly from the signals of the individual detectors. Furthermore, the maximum wavelength of one radiation detector is preferably outside the detection range of the other radiation detector.

In a further preferred embodiment, two radiation detectors of the detector arrangement are designed such that the detection area of one radiation detector only partially or completely covers the detection area of the other radiation detector. In the case of a partial overlap, the assignment of the spectral components to the respective radiation detector can be facilitated, whereas with complete coverage, the radiation detectors can possibly be manufactured more cost-effectively due to a waiver of the adaptation of the spectral sensitivity distributions or the detection regions.

In a further preferred refinement, two radiation detectors of the detector arrangement are designed such that the spectral sensitivity distribution of one radiation detector of the detector arrangement overlaps, in particular only partially or completely, with the spectral sensitivity distribution of the other radiation detector. Due to the overlap, the formation of a predetermined detection wavelength range, in which the detector arrangement is provided for radiation detection and / or formed, can be facilitated. In particular, the detection wavelength range compared to the Detection range of a single radiation detector to be widened.

In a further preferred embodiment, two radiation detectors of the detector arrangement are designed such that the maximum wavelength of the spectral

Sensitivity distribution of the one radiation detector of the detector array is different from the maximum wavelength of the spectral sensitivity distribution of the other radiation detector of the detector array, wherein the spectral sensitivity distribution of the radiation detector of the detector array with the larger maximum wavelength with that spectral sensitivity distribution of the radiation detector of the detector array with the smaller maximum wavelength, especially for wavelengths below the smaller maximum wavelength, at least partially coincident. Preferably, the spectral sensitivity distribution of the radiation detector having the larger maximum wavelength completely covers that of the radiation detector having the smaller maximum wavelength.

A radiation detector of the detector arrangement can thus generate a significant signal in, possibly over the entire detection range, of a further radiation detector. In order to determine spectral components from the incident radiation, an arithmetic operation, for example the formation of the difference between the signals of the radiation detector and the further radiation detector, can be carried out after detecting the signals of the detectors. From the signal of the one radiation detector, in particular directly, a first spectral component and from the result obtained from the arithmetic operation, a second spectral component in the incident radiation can be determined.

In a further preferred refinement, the detector arrangement is provided for determining color components, in particular portions of the primary colors red, green and blue, in radiation incident on the detector arrangement and / or _ _{1 ±} _

educated.

By detecting the signals of the detection regions corresponding to different colors with preference to the different radiation detectors, it is possible to obtain information about the spectral color components in the radiation incident on the radiation detector.

In a further preferred embodiment of the invention, the detector arrangement is designed to determine the color impression, for example the color locus and / or the color temperature, of the incident radiation. The color locus is usually given by the color coordinates (x and y) in the CIE diagram. If, for example, the incident radiation contains blue components to an increased extent, a correspondingly high signal is generated in a radiation detector sensitive in this spectral range, while correspondingly low signals are preferably generated in the radiation detectors for the red and green spectral ranges. By appropriate evaluation of the three mutually independent signals, which can preferably be assigned to the respective color component to be determined, signals can accordingly be obtained about the color locus of the incident radiation.

For example, the detector arrangement for

Color fraction determination three radiation detectors, wherein the first radiation detector for detecting radiation in the blue spectral range, the second radiation detector for detecting radiation in the green spectral range and the third radiation detector for detecting radiation in the red spectral range provided and / or formed. These radiation detectors are preferably only significantly sensitive in one of the visible spectral ranges mentioned.

In a further preferred embodiment, the first radiation detector is sensitive in the blue, green and red spectral range, the second radiation detector is sensitive only in the green and blue spectral range and the third radiation detector is only in the blue spectral range - _~

sensitive. Since the first radiation detector generates a signal in both the blue, green and red spectral range, the determination of spectral components, in particular blue and green components, from the signal of the detector arrangement is in contrast to immediate acquisition of the information about the color components from those in the individual components However, the detectors of the detector arrangement can be manufactured more cheaply, since an adaptation of the detection ranges of the individual detectors, such as filter layers, can be dispensed with each other.

The radiation detectors thus generate signals in the blue spectral range. A radiation detector which generates a signal not only in the detection area assigned to it but also in the detection area assigned to another radiation detector can be correlated with the signal of the other radiation detector. A signal generated in the radiation detector can be easily distinguished from an uncontrolled background noise by comparison with the signal of the other radiation detector, which is likewise sensitive to the spectral component in question.

The color components can be obtained, for example, by means of forming differences from signals of discrete radiation detectors.

In a further preferred embodiment, the semiconductor body, in particular the active region, the functional layer and / or the filter layer structure, the first radiation detector and / or the second radiation detector contains a III-V semiconductor material, in particular a material from the III-V semiconductor material system In _x Ga _y Ali_ _x - _y P, where O≤x≤l, O≤y≤l and x + y≤l, preferably y ≠ O and / or y ≠ l, In _x Ga ₇ Al ₁ -X _-7 As, with O≤x≤l, O≤y≤l and x + y≤l, preferably y ≠ O and / or y ≠ l, and / or In _x Ga _y Al _x-y N, with O≤x≤l , O≤y≤l and x + y≤l, preferably y ≠ O and / or y ≠ l. III-V semiconductor materials can, as already mentioned above, be distinguished by particularly advantageous high internal quantum efficiencies. In the material system In _x Ga _y Ali_ _x _ _y P can be easily formed active areas or functional layers, by means of which the entire visible spectral range can be covered.

Furthermore, a filter layer comprising a III-V semiconductor material, in particular from the material system In _x Ga _y Ali. _x _y P or In _x Ga _y Ali_ _x - _y As, for a filter layer structure simplified in a semiconductor body, in particular in a semiconductor body on In _x Ga ₇ Ali_ _x . _y P- and / or In _x Ga _y Ali- _X. _y As base, monolithically integrated. As a result, a particularly compact and small design of the radiation detector with the filter layer structure can be achieved in a simplified manner.

In a further preferred refinement, the functional layer, in particular the semiconductor body, the filter layer structure and / or the active region, of a radiation detector of the detector arrangement and the functional layer, in particular the semiconductor body, the filter layer structure and / or the active region, are based on a further radiation detector of the detector arrangement same semiconductor material system. The manufacture of the radiation detectors of the detector arrangement can thus be simplified.

In a method according to the invention for determining various spectral components in a radiation incident on a detector arrangement having a plurality of radiation detectors, wherein a first radiation detector of the detector arrangement has a detection area assigned thereto, a second radiation detector of the detector arrangement has a detection area assigned to it and at least one of the radiation detectors Detector arrangement comprises a Halbleiterkδrper with an active signal area provided for the active area, are first a first wavelength range for a first to be determined spectral Proportion and a second wavelength range for a second, different from the first spectral component to be determined spectral component. Here, the detection range of the first radiation detector comprises the first wavelength range, the detection range of the second radiation detector comprises the second wavelength range and the detection range of the second radiation detector overlaps with the first wavelength range. The radiation detectors are preferably arranged laterally next to each other and / or implemented discretely as individual detectors. Furthermore, the first and the second radiation detector preferably have a semiconductor body with an active region provided for signal generation.

Then the signals generated, in particular due to the incident radiation, by means of the first radiation detector and by means of the second radiation detector are detected.

Subsequently, an arithmetic operation is performed with the signal originating from the first radiation detector and the signal originating from the second radiation detector, which yields a result. From the result of the arithmetic operation of the second spectral component and from the signal of the first radiation detector, in particular directly, the first spectral component can be determined. Preferably, the second spectral component and / or the second wavelength range comprises wavelengths greater than those of the first spectral component or the first wavelength range.

Preferably, in the arithmetic operation, the difference of the signal generated by the second radiation detector and the signal generated by the first radiation detector is formed. The spectral components in the incident radiation can be determined by means of the signal generated by the first radiation detector and by means of the result of the previously formed difference. In this case, the first spectral component in the incident radiation is preferred by means of the signal generated by the first radiation detector and / or the second - -

Spectral component in the incident radiation determined by means of the difference previously formed.

In a preferred embodiment, the detection range of the second radiation detector completely covers the first wavelength range. The second radiation detector is thus sensitive to the first and the second spectral component. An adaptation of the detection range of a radiation detector of the detector arrangement, for example by expensive filtering, can thus be dispensed with with advantage. The detection area and / or the sensitivity distribution can be determined essentially solely by the active area, in particular the functional layer, of the radiation detector.

In a further preferred embodiment, the semiconductor body, in particular the active region, of the first radiation detector and / or of the second radiation detector contains a III-V semiconductor material, in particular a material from the III-V semiconductor material system In _x Ga _y Ali_ _x _ _y P, with O≤x≤l, O≤y≤l and x + y≤l, preferably y ≠ O and / or y ≠ l, In _x Ga ₇ Ali- _X _ _y As, ^' with O≤x≤l, O ≤y≤l and x + y≤l, preferably y ≠ O and / or y ≠ l, and / or In _x Ga _y Ali_ _x _ _y N, where O≤x≤l, O≤y≤l and x + y≤l, preferably y ≠ O and / or y ≠ l.

Such semiconductor materials are, as already mentioned above, particularly suitable for a radiation detector in the visible spectral range.

In the method according to the invention, a detector arrangement according to the invention is preferably used, so that the features described above and below for the detector arrangement can also be used for the method according to the invention, and vice versa.

Above, a plurality of preferred embodiments have been described. For this purpose, reference has often been made to two radiation detectors of the detector arrangement. It should be noted that the features cited here are not all realized with a single radiation detector pair of the detector arrangement _ _{± ß} _

have to. Rather, individual features can be realized with different radiation detector pairs of the detector arrangement.

Further features, advantageous embodiments and advantages of the invention will become apparent from the description of the following embodiments in conjunction with the figures.

Show it:

Figure 1 is a schematic sectional view of a

Embodiment of a detector arrangement according to the invention in Figure IA, a qualitative representation of the spectral sensitivity distribution of a radiation detector in Figure IB and in Figure ID the spectral sensitivity distribution of the detector arrangement of Figure IA with corresponding to the table in Figure IC formed elements and

2 shows in FIG. 2A a schematic sectional view of a second exemplary embodiment of a detector arrangement according to the invention, in FIG. 2C the spectral one

Sensitivity distribution of a detector arrangement according to FIG. 2A with elements corresponding to the table in FIG. 2B and in FIG. 2D difference curves of the spectral sensitivity distributions of radiation detectors according to FIG. 2C.

The same, similar and equally acting elements are provided in the figures with the same reference numerals.

In FIG. 1A, a first exemplary embodiment of a detector arrangement according to the invention is schematically illustrated by means of a sectional view. The detector arrangement 10 comprises a first radiation detector 1, a second radiation detector 2 and a third radiation detector 3. The radiation detectors 1, 2 and 3 of the detector arrangement each comprise a semiconductor body 11, 21 and 31, respectively. The semiconductor bodies of the radiation detectors each have an active region 12 , 22 _ -yη_

or 32, which is provided for signal generation and radiation reception. The active region of the respective radiation detector preferably comprises at least one functional layer which can absorb radiation components from a radiation 40 incident on the detector arrangement. In particular, the active region can be formed by a functional layer.

The active region 12, 22 or 32 of at least one radiation detector of the detector arrangement, preferably of the first, of the second and of the third radiation detector, contains a III-V semiconductor material and / or it is the active region of a first radiation detector of the detector arrangement of that of another Radiation detector of the detector arrangement executed differently. Preferably, the active regions of the first radiation detector, the second radiation detector and the third radiation detector are made in pairs different from each other.

Furthermore, the active region of the first radiation detector, of the second radiation detector and / or of the third radiation detector is preferably arranged between a first barrier layer 13, 23 or 33 and a second barrier layer 14, 24 and 34, respectively. The barrier layers of a radiation detector, such. As the layers 13 and 14 of the first radiation detector 1, preferably have different conductivity types (n-type or p-type). The semiconductor bodies of the radiation detectors are furthermore preferably each arranged on a carrier 15, 25 or 35. The carrier advantageously mechanically stabilizes the respective semiconductor body arranged thereon. By way of example, the carrier may comprise the growth substrate on which the semiconductor body arranged on the carrier has grown, in particular epitaxially, or the carrier may be formed by this growth substrate. The supports 15, 25 and 35 preferably contain a same material or are formed from the same materials.

The radiation detectors of the detector arrangement are preferably different, in particular different in pairs, Detection areas, ie areas in which the radiation detectors generate a significant signal assigned. If the detector arrangement is designed to detect radiation over the visible spectral range, for example the first radiation detector 1 is assigned a detection area which comprises the blue spectral range, the second radiation detector 2 is assigned a detection area comprising the green spectral range, and the third radiation detector 3 Assigned detection range, which includes the red spectral range. The detection areas are preferably matched to one another in such a way that a detection area comprising a smaller wavelength overlaps with, in particular only, the adjacent longer-wavelength detection area. In this way, the detection of radiation over a coherent detection wavelength range, for example the visible spectral range, can be achieved in a simplified manner with signal generation that is significant over substantially the entire detection wavelength range. The detection range of the respective radiation detector can be determined by the formation of the functional layer of the active region. Expediently, the functional layers of radiation detectors which have different detection areas are designed differently.

Preferably, the functional layers of

Radiation detectors, which are intended for different detection areas, different band gaps and / or thicknesses. The band gap essentially defines the wavelength range absorbed by the incident radiation. In particular, the bandgap defines an upper limit of this wavelength range. The detection range, in particular an upper limit wavelength of the detection range, can thus be set via the band gap of the functional layer. By selecting the thickness of the functional layer, the proportion of radiation power absorbed by the incident radiation 40 and thus the signal strength generated in the respective radiation detector can be set in a targeted manner. The radiation detectors are preferably such -. -

coordinated so that their respective spectral sensitivity distributions assume the same maximum values. The comparison in the individual radiation detectors generated signals and the determination of different spectral components in the incident on the detector array 10 radiation 40 can be facilitated.

In order to be able to detect the electrical signals generated in the active regions 12, 22 and 32, the radiation detectors preferably have a first electrical contact 16, 26 or 36 and a second electrical contact 17, 27 and 37, respectively. The first and second contacts are particularly preferably arranged on opposite sides of the carrier 15, 25 and 35, respectively. The first and second contacts are electrically connected to the respective active region. The active region is preferably arranged between the first and the second contact. For this purpose, if the carrier contains a semiconductor material, such as GaAs, it may be doped to increase the conductivity.

The radiation detectors are preferably arranged laterally next to one another. In particular, the radiation detectors 1, 2 and 3 can be arranged on a common carrier element 100. The carrier element 100 can be designed, for example, as part of a housing body, in particular a plastic housing body of an optoelectronic component, or as a printed circuit board. A housing body protects the radiation detector chips (a carrier with the semiconductor body arranged thereon) from harmful external influences. On a circuit board, the

Radiation detectors are electrically contacted, for example, by the contacts 17, 27 and 37 and 16, 26 and 36 are electrically connected to the conductor tracks of the circuit board.

Proportions of the radiation 40 entering the semiconductor body 11, 21, or 31 of the respective radiation detector 1, 2, or 3 on a radiation entrance side 18, 28, or 38 of the respective radiation detector can correspond to the band gap of FIG - -

Functional layer of the respective area are absorbed. The subsequently generated electron-hole pairs contribute to the signal of the radiation detectors. The wavelength dependence of the generated signal determines the spectral

Sensitivity distribution of the respective radiation detector. The sensitivity distribution of the individual radiation detectors preferably has a maximum at a maximum wavelength, which expediently lies in the detection area assigned to the respective radiation detector.

FIG. 1B qualitatively shows the dependence of the spectral sensitivity distribution R on the wavelength λ of the incident radiation for a single radiation detector. The spectral sensitivity distribution 101 has a maximum 106 at the maximum wavelength λ _m and a short-wave limit λ _a and a long-wavelength cut-off wavelength X] ₃ . The detection range of the radiation detector is limited by the wavelengths λ _a and X] ₃ .

High-energy short-wave radiation can also be absorbed in active regions or functional layers provided for detection of longer-wave radiation and accordingly generate a signal. By means of a filter layer structure which comprises at least one filter layer and absorbs radiation having a wavelength smaller or smaller than the maximum wavelength corresponding to the band gap of the functional layer of the active region, signal generation due to short-wave radiation can be reduced in accordance with the short-wave radiation fraction absorbed in the filter layer. The detection range of the respective radiation detector can, if appropriate in combination with a functional layer of a suitable band gap, be adapted to a spectral component to be determined. Preferably, the filter layer structure is monolithically integrated in the semiconductor body and arranged between the radiation entrance side of the semiconductor body and the active region of the radiation detector. _ -

In the present exemplary embodiment, the second radiation detector 2 and the third radiation detector 3 have a filter layer structure 29 and 39, respectively. The filter layer structure 39 of the third radiation detector has a first filter layer 391 and a second filter layer 392, which preferably have different band gaps and thicknesses. The filter layer structure makes it easier to reduce signal generation in active regions of radiation detectors provided for longer-wave radiation in the short-wave range-smaller than the maximum wavelength. Shortwave radiation is increasingly absorbed in the filter layer structure and thus can only generate signals in the active region to a reduced extent.

On the part of the first contact of the respective radiation detector, which is arranged on the side of the semiconductor body opposite the carrier, the semiconductor body can be terminated by a contact layer 160, 260 or 360. The contact layer has advantageous electrical contact properties for the first contact.

For III-V semiconductor materials

Due to the easily achievable high internal quantum efficiency, radiation detectors for the visible spectral range are particularly suitable for the material system In _x Ga _y Ali_ _x . _y P. This material system is particularly suitable for the active area.

For the detection of differently colored spectral components, in particular components of the primary colors red, green and blue, in the incident radiation, semiconductor bodies which have elements which are formed according to the table shown in FIG. 1C are particularly suitable for the radiation detectors. The carrier 15, 25 and 35 can each be provided by an n-GaAs growth substrate on which the semiconductor bodies 11, 21 and 31 are grown epitaxially. Preferably, the semiconductor body is based on the material system _0, ₅ (Ga _x Al _x) _0, sp 0 <x <1, which is characterized by good lattice matching to a GaAs growth substrate. About the Al content x, the Band gap of a semiconductor layer can be adjusted from this material system.

In the table according to FIG. 1C, D denotes the thickness, E _G the band gap relevant for the absorption, in particular the direct band gap, and λ _G the wavelength corresponding to this band gap.

The filter layer structure 29 has a filter layer which is formed in thickness and composition corresponding to the active region 12 of the first radiation detector. The same applies to the first filter layer 391 of the third radiation detector 3. The second filter layer 392 of the filter layer structure 39 of the third radiation detector 3 is formed in thickness and composition corresponding to the active region 22 of the second radiation detector. A filter layer of a radiation detector having a detection region which, compared to that of a further radiation detector, comprises larger wavelengths, is accordingly designed in terms of composition and thickness in accordance with the functional layer of the further radiation detector.

The spectral sensitivity distribution of the individual radiation detectors of a detector arrangement formed in this way is shown schematically in FIG. For the ID, the spectral sensitivity distribution of a detector arrangement according to FIG. 1A was simulated, the simulation of the table in FIG. IC being based on corresponding data. In FIG. 1D, the wavelength dependence of the responsivity of the generated photocurrent in amps per watt of the incident radiation power on the wavelength of the radiation incident on the detector array is plotted in nm.

In Figure ID, the spectral sensitivity distribution 101 of the first radiation detector 1, the spectral

Sensitivity distribution 102 of the second radiation detector 2 and the spectral sensitivity distribution 103 of the third radiation detector 3 shown. -

The detection range of the first radiation detector 1 ranges from including λ _a] _ «400 nm up to and including X] ₃ 1 ^Ä 600 nm, that of the second radiation detector 2 by including λ _a, 2 ^{ö 480 nm} b ^ ¹³ including X] ₃ ^ * ⁶⁵ ° ^{nm and} d that of the third radiation detector 3 from including Xa 3 * 550 nm up to and including Xj ₃ 3 «675 nm.

Thus, apart from the range between 675nm and 700nm, the detector array substantially covers the entire visible spectral range, which is illustrated by curve 104, which represents the sensitivity of a brightly adapted human eye according to the CIE standard. The detection areas of the radiation detectors overlap with each other. In particular, the detection range of the longest wavelength radiation detector 3 overlaps that of the radiation detector 1 provided for the shortest wavelength radiation. This overlap can optionally be avoided by otherwise forming the active zone of the radiation detector 1 or suitable filtering. The determination of spectral components in the incident radiation 40 can thus be facilitated.

The spectral sensitivity distributions 101, 102 and 103 each have a maximum at a maximum wavelength λ _m , i (i = 1, 2, 3). The first radiation detector 1 is assigned to the blue spectral range, the second radiation detector 102 to the green spectral range and the third radiation detector 103 to the red spectral range. In particular, the maximum wavelengths with λ _{TO /} i = 490 nm, λ _{m / 2} = 555 nm and λ _{m / 3} «610 nm are in the spectral or detection ranges assigned to the respective radiation detectors. The short-wave edge of the spectral sensitivity distributions of the second radiation detector 2 and the third radiation detector 3 is shaped for wavelengths smaller than the respective maximum wavelength by absorbing wavelengths from the incident radiation smaller than the maximum wavelength in the filter layer structure of these radiation detectors. Preferably, the spectral sensitivity distributions are formed through the filter layer such that two spectral sensitivity distributions with adjacent ones Cut maximum latencies at a value less than half the maximum value. This is the case in the present training example. Half the maximum value is about 0.15 A / W. In particular, the filter layer structure determines the short-wave limit of the detection range of the respective radiation detector. Since in the material system In _x Ga ₇ Al ₁ . _x . _y P only comparatively low sensitivities can be achieved in the blue spectral range, an additional filter layer structure for shaping the short-wave edge of the sensitivity distribution can be dispensed with in the case of the first radiation detector.

Due to the coordination of the radiation detectors on different-colored spectral regions can be obtained directly from the signals detected by the discrete radiation detectors on color components in the radiation incident on the detector array. Further, the color impression can be determined.

Furthermore, the radiation detectors of the detector arrangement are preferably matched to one another such that they have substantially the same maximum values. This can be achieved by suitable design of the active region, in particular the functional layer of the respective radiation detector. In the present exemplary embodiment, the three radiation detectors essentially have the common maximum value of 0.3 A / W.

The semiconductor body 31 of the radiation detector 3 provided for the long-wave radiation has, according to the table above, a considerable thickness of approximately 5 μm. This considerable thickness is due to the filter layer structure which serves to tune the detection areas and which absorbs wavelengths from wavelength ranges which are undesirable for signal generation.

It should be noted that not only the filter layer structure alone can serve to shape the short-wave edge of the spectral sensitivity distribution of the radiation detector. Rather, the barrier layers arranged with respect to the active region on the radiation inlet side can also be provided for filtering. For this purpose, the barrier layers of the radiation detectors of the detector arrangement have different thicknesses (compare the table in FIG. 1C). With the radiation detectors 2 and 3 designed for longer-wave radiation, short-wave radiation is thus increasingly absorbed in the respective barrier layers.

FIG. 2 shows in FIG. 2A a schematic sectional view of a second exemplary embodiment of a detector arrangement according to the invention, in FIG. 2C the spectral

The detector arrangement according to the second exemplary embodiment again comprises a first radiation detector 1, a second radiation detector 2 and a third radiation detector 3. The embodiment according to FIG. 2A essentially corresponds to the first exemplary embodiment.

In contrast to the first exemplary embodiment, the second radiation detector 2 and the third radiation detector 3 do not have the filter layer structures 29 or 39. The third radiation detector 3 is sensitive over the detection range of the second and the first radiation detector. The second radiation detector in turn is sensitive over the detection range of the first radiation detector, but insensitive in the detection range of the third. The detection regions of the first, the second and the third radiation detector can in particular have a common lower limit wavelength.

In order to determine spectral components from the incident radiation 40 by means of such a detector arrangement, differences can be formed from the spectral sensitivity distributions of the first, the second and the third radiation detector _ _

become. From the signal of the first radiation detector can advantageously directly the information about a first spectral component, from the difference of the spectral

Sensitivity distribution of the second radiation detector and the first radiation detector that over a second spectral component and from the difference of the spectral sensitivity distribution of the third radiation detector with the spectral sensitivity distribution of the second radiation detector that are obtained over a third spectral component.

In the table shown in FIG. 2B, elements which are particularly suitable for semiconductor bodies of radiation detectors according to the second exemplary embodiment are specified. D denotes the thickness, E _G the absorption, in particular direct, band gap, and λ _G the wavelength corresponding to this band gap.

The spectral sensitivity distribution of the individual radiation detectors of a detector arrangement designed according to this table is shown schematically in FIG. 2C. For FIG. 2C, the spectral sensitivity distribution of a detector arrangement according to FIG. 2A was simulated, the simulation of FIG. 2B being based on corresponding data. In FIG. 2C, the wavelength dependence of the responsivity of the generated photocurrent in amperes per watt of the incident radiation power on the wavelength of the radiation incident on the detector array is plotted in nm.

In Figure 2C, the spectral sensitivity distribution 101 of the first radiation detector, the spectral

Sensitivity distribution 102 of the second radiation detector and the spectral sensitivity distribution 103 of the third radiation detector of a detector arrangement shown in Figure 2A. Furthermore, the sensitivity distribution of the brightly adapted human eye 104 is shown with a maximum at about 555 nm. - -

The first radiation detector 1 for the blue spectral region has the same spectral sensitivity distribution as the detector of FIG. ID, since it is manufactured in accordance with that of FIG. 1D. In the case of the second and the third radiation detector, the filter layer structure was dispensed with, so that these detectors are sensitive to short-wavelength wavelength ranges compared to FIG.

In particular, the sensitivity distributions of the first, the second and the third radiation detector for wavelengths smaller than the maximum wavelength λ _m , i of the first radiation detector overlap. Furthermore, the spectral sensitivity distributions of the first, the second and the third radiation detector for wavelengths smaller than λ _m , i are congruent in the region 105 of the spectral sensitivity distribution of the detector arrangement 10.

The detection range of the first radiation detector extending from including the common short wavelength cutoff wavelength of the three radiation detectors λ _a "400 nm to λj-, ^« 600 nm, that of the second radiation detector by including λ _a to including XT ₀ 2 "650 nm and that of the third radiation detector of including λ _a up to and including X] ₃ 3 '675 nm. the peak wavelength of the spectral sensitivity distribution of the first radiation detector λ _m, i is nm at about 490, the peak wavelength λ _m, ₂ of the spectral

Sensitivity distribution 102 of the second radiation detector at approximately 525 nm and the maximum wavelength λ _{m, 3 of} the spectral sensitivity distribution 103 of the third radiation detector at approximately 570 nm. Λ _m , ₃ is therefore in the green spectral region, the detection region for which the second radiation detector is provided.

The individual radiation detectors thus have significant overlapping or even overlapping ones

Sensitivity distributions or detection areas, which complicates the assignment of spectral components to the respective detector signal. From a detector arrangement with the _{9 R}

Although the sensitivity distribution according to FIG. 2C makes it more difficult to obtain information about spectral components in the simple radiation directly from the detector signals, such radiation detectors can be manufactured more cost-effectively because of the absence of filter layer structures and consequently reduced growth times.

The determination of color components from the incident radiation can be carried out in the detector arrangement according to FIG. 2A by means of the formation of differences of the signals generated in the radiation detectors on the basis of the incident radiation. In this case, it is preferred to subtract from a spectral sensitivity distribution of a radiation detector, in particular exclusively that of a further radiation detector with a shorter-wavelength detection range. Preferably, the shorter-wavelength detection range of that of the radiation detector wavelength-related, in particular on the long-wavelength side of the two sensitivity distributions, the closest detection range.

FIG. 2D shows curves resulting from such a difference formation. The curve 101 corresponds to the spectral sensitivity distribution of the first radiation detector 1. In order to obtain the curve 112, the spectral sensitivity distribution of the first radiation detector 101 has been changed from the spectral

Sensitivity distribution of the second radiation detector 102 subtracted from Figure 2C. To obtain the curve 123, the spectral sensitivity distribution 102 of the second radiation detector was determined from the spectral

Sensitivity distribution 103 of the third radiation detector deducted. From the signal of the first radiation detector 101, a blue spectral component can be determined. The difference curve 112 has a maximum at λ _{D / 2} «540 nm and is provided for determining spectral components in the green spectral range. The difference curve 123 has a maximum at λ _{D / 2} * 595 nm and is for determining spectral components in _OQ

- 2, 3 -

red spectral range provided. The difference curve 123 overlaps with the difference curve 112.

The spectral sensitivity distribution 101 of the first radiation detector for the short-wave radiation overlaps with the difference curve 112. The wavelength range covered by the spectral sensitivity distribution 101 extends from 400 nm to 600 nm, the area covered by the difference curve 112 approximately from 450 nm to 665 nm, and Wavelength range of approximately 540 nm to 650 nm covered by the difference curve 123. Apart from the range between 655 nm and 700 nm, the entire visible spectral range is coherently covered by means of the difference curves and the detection range of the first radiation detector.

This patent application claims the priorities of German patent applications DE 10 2005 024 660.5 of May 30, 2005 and DE 10 2005 043 918.7 of September 14, 2005, the entire disclosure content of which is hereby explicitly incorporated by reference into the present patent application.

The invention is not limited by the description with reference to the embodiments. Rather, the invention encompasses any novel feature as well as any combination of features, including in particular any combination of features in the claims, even if this feature or combination itself is not explicitly stated in the patent claims or exemplary embodiments.

Claims

_ 3 Q _Patent claims

A detector array comprising a plurality of discrete radiation detectors (1, 2, 3), wherein

a first radiation detector (1, 2, 3) and a second radiation detector (1, 2, 3) of the detector arrangement (10) each have a semiconductor body (11, 21, 31) with an active region (12, 12) provided for radiation reception and signal generation; 22, 32) and in each case have a detection area assigned to the respective radiation detector,

- Wherein the semiconductor body of at least one radiation detector contains a III-V semiconductor material and / or

- Wherein the active region of the first radiation detector is designed differently from the active region of the second radiation detector.

2. A detector arrangement according to claim 1, characterized in that a band gap and / or a thickness of a functional layer of the active region (12, 22, 32) of the first radiation detector (1,

2, 3) is different from a band gap or a thickness of a functional layer of the active region (12, 22, 32) of the second radiation detector (1, 2, 3).

3. A detector arrangement according to claim 2, characterized in that the band gap of the functional layer of the active region (12, 22, 32) of the first radiation detector (1, 2, 3) corresponding wavelength and / or the band gap of the functional layer of the active region ( 12, 22, 32) of the second radiation detector (1, 2, 3) corresponding wavelength in the visible spectral range.

4. A detector arrangement according to claim 2 or 3, characterized in that the band gap of the functional layer of the active region (12,

22, 32) of the first radiation detector (1, 2, 3) corresponding

Wavelength and the band gap of the functional layer of the _

active region (12, 22, 32) of the second radiation detector (1, 2, 3) corresponding wavelength in different-colored spectral ranges.

5. Detector arrangement according to one of the preceding claims, characterized in that the detector arrangement (10) over a continuous predetermined detection wavelength range is sensitive.

6. A detector arrangement according to one of the preceding claims, characterized in that the first radiation detector and the second radiation detector each having a respective radiation detector associated predetermined spectral sensitivity distribution (101, 102, 103) having a maximum at a predetermined maximum wavelength.

7. Detector arrangement according to claim 6, characterized in that

at least one radiation detector (2, 3) of the detector arrangement has a filter layer structure (29, 39) which is monolithically integrated in the semiconductor body (21, 31) of this radiation detector and has at least one filter layer (29, 391, 392),

- The filter layer structure absorbs radiation in a wavelength range, the wavelengths smaller than the maximum wavelength of the spectral sensitivity distribution

(102, 103) of this radiation detector, and

the filter layer structure between a

Radiation inlet side (18, 28, 38) of the semiconductor body and the active region is arranged.

8. A detector arrangement according to claim 7, characterized in that the filter layer structure (39) has a plurality of filter layers (391, 392).

9. A detector arrangement according to claim 8, characterized in that the filter layers (391, 392) of the filter layer structure (39) - -

have different band gaps and / or thicknesses.

10. A detector arrangement according to one of claims 2 to 9, characterized in that the detection range of a radiation detector (1, 2, 3) of the detector arrangement includes the band gap of the functional layer of a further radiation detector (1, 2, 3) of the detector array corresponding wavelength.

11. A detector arrangement according to one of claims 6 to 10, characterized in that the maximum wavelength of the sensitivity distribution (102, 103) of a radiation detector (2, 3) of the detector arrangement (10) within the detection range of a further radiation detector (1, 2) of the detector array is located ,

12. A detector arrangement according to one of the preceding claims, characterized in that the detection area of a radiation detector (1, 2, 3) of the detector arrangement (10) the detection area of a further radiation detector (1, 2, 3) of the detector arrangement (10) only partially or completely covered.

13. A detector arrangement according to one of claims 6 to 12, characterized in that the spectral sensitivity distribution (101, 102, 103) of a radiation detector (1, 2, 3) of the detector arrangement (10) with the spectral sensitivity distribution (101, 102, 103) a further radiation detector (1, 2, 3) of the detector arrangement, in particular only partially or completely, overlaps.

14. Detector arrangement according to one of claims 6 to 13, characterized in that

the maximum wavelength of the spectral sensitivity distribution (101, 102, 103) of a

Radiation detector (1, 2, 3) of the detector arrangement (10) is different from the maximum wavelength of the spectral sensitivity distribution (101, 102, 103) of a further radiation detector (1, 2, 3) of the detector arrangement, - The spectral sensitivity distribution of the radiation detector of the detector arrangement having the larger maximum wavelength with that spectral sensitivity distribution of the radiation detector of the detector arrangement with the smaller maximum wavelength at least in sections is congruent.

15. A detector arrangement according to one of the preceding claims, characterized in that the detector arrangement (10) for determining color components, in particular on the primary colors red, green and blue, provided in the detector array incident radiation (40) and / or is formed.

16. A detector arrangement according to one of the preceding claims, characterized in that the detector arrangement (10) has a third radiation detector, wherein the first radiation detector (1) for detecting radiation in the blue spectral range, the second radiation detector (2) for detecting radiation in the green Spectral range and the third radiation detector (3) provided for detecting radiation in the red spectral range and / or is formed.

17. A detector arrangement according to one of the preceding claims, characterized in that the semiconductor body (11, 21, 31), in particular the active region (12, 22, 32), the functional layer and / or the filter layer structure (29, 39), of the first Radiation detector and / or the second radiation detector, a III-V semiconductor material, in particular a material of the III-V semiconductor material system In _x Ga _y Al _1-xy P with O≤x≤l, O≤y≤l and x + y≤ l, contains.

18. A method for determining various spectral components in a radiation incident on a detector arrangement (10) having a plurality of radiation detectors (1, 2, 3), wherein a first radiation detector of the detector arrangement has a detection area assigned to it, a second one _

Radiation detector of the detector array has a detection area associated therewith and at least one of the radiation detectors of the detector array comprises a semiconductor body with an active region for signal generation characterized by the steps of a) defining a first wavelength range for a first spectral portion to be determined and setting a second wavelength range for a second spectral component to be determined which is different from the first spectral component, wherein the detection range of the first radiation detector (1) comprises the first wavelength range, the detection range of the second radiation detector (2) comprises the second wavelength range and the detection range of the second radiation detector overlaps with the first wavelength range , b) detecting the signal generated by the first radiation detector and the signal generated by the second radiation detector, c) forming the D d) determining the first spectral component in the incident radiation by means of the signal generated by the first radiation detector and / or determining the second spectral component in the incident radiation by means of the difference formed in step c).

19. The method according to claim 18, characterized in that the detection range of the second radiation detector (2) completely covers the first wavelength range.

20. The method according to claim 18 or 19, characterized in that the Halbleiterkδrper (11, 21, 31), in particular the active region (12, 22, 32), the first radiation detector (1, 2, 3) and / or the second Radiation detector (1, 2, 3) a III-V semiconductor material, in particular a material of the III-V semiconductor material system In _x Ga _y Ali_ _xy P with O≤x≤l, O≤y≤l and x + y≤l.

21. The method according to any one of claims 18 to 20, characterized in that the detector arrangement is a detector arrangement (10) according to one of claims 1 to 17.