Radiation emitting semiconductor device

Abstract

A radiation emitting semiconductor device (1) comprising a semiconductor body with a semiconductor layer sequence (2) is specified, wherein the semiconductor layer sequence (2) comprises an active region configured to emit radiation with a peak emission wavelength in the near-infrared spectral range, and wherein the semiconductor layer sequence (2) comprises an absorber (3) configured to at least partially absorb a shortwave radiation component, the absorber (3) having a cut-off wavelength that is shorter than the peak emission wavelength.

Description

[0001] Description

[0002] RADIATION EMITTING SEMICONDUCTOR DEVICE

[0003] The present application relates to a radiation emitting semiconductor device .

[0004] Driver monitoring systems ( DMS ) may be used to detect occupants and locate them spatially within a vehicle . These systems typically use infrared light to illuminate the scene . However, light emitting diodes ( LEDs ) emitting in the infrared spectral range may also produce a low amount of visible light that may be perceived by sensitive eyes or under low lighting conditions , for example during night operation . This perceived red light may distract the driver and pose a safety risk .

[0005] An obj ect of the present application is to facilitate illumination in the infrared spectral range .

[0006] This obj ect is achieved inter alia by a radiation emitting semiconductor device according to claim 1 . Further developments and expediencies are the subj ect of the dependent claims .

[0007] A radiation emitting semiconductor device comprising a semiconductor body with a semiconductor layer sequence is speci fied . For example , the radiation emitting semiconductor device is configured to emit incoherent radiation . For example , the radiation emitting semiconductor device is an LED semiconductor chip, wherein the term light is not limited to visible light , but also includes electromagnetic radiation in the infrared spectral range . In particular the semiconductor layer sequence forming the semiconductor body is formed by an epitaxial semiconductor material . For example , the semiconductor layer sequence is epitaxially grown by metal organic chemical vapor phase deposition (MOCVD) or metal organic chemical vapor phase epitaxy (MOVPE ) or molecular beam epitaxy (MBE ) . In particular, all layers of the semiconductor layer sequence are epitaxially formed layers .

[0008] According to at least one embodiment of the radiation emitting semiconductor device , the semiconductor layer sequence comprises an active region configured to emit radiation with a peak emission wavelength in the near infrared spectral range . For example , the peak emission wavelength is at least 820 nm or at least 850 nm and / or at most 1 . 2 pm or at most 1 . 1 pm or at most 1 pm .

[0009] For example , the active region is arranged between a first semiconductor layer of a first conductivity type and a second semiconductor layer of a second conductivity type di f ferent from the first conductivity type so that the active region is located in a pn-j unction .

[0010] According to at least one embodiment of the radiation emitting semiconductor device , the semiconductor layer sequence comprises an absorber configured to at least partially absorb a shortwave radiation component of the radiation . In other words , the photons having the highest energy within the spectral emission distribution of the emitted radiation can be absorbed by the absorber whereas the absorber is transmissive to photons having a lower energy . For example , the absorber is configured to absorb at least radiation with wavelengths shorter than or equal to 800 nm . In particular, the absorber has a cutof f wavelength that is shorter than the peak emission wavelength . For example , the cutof f wavelength is by at least 10 nm or at least 20 nm or at least 50 nm shorter than the peak emission wavelength .

[0011] For example , the cutof f wavelength of the absorber is at least 750 nm or at least 780 nm or at least 800 nm and / or at most 820 nm or at most 850 nm or at most 900 nm .

[0012] In at least one embodiment of the radiation emitting semiconductor device , the radiation emitting semiconductor device comprises a semiconductor body with a semiconductor layer sequence wherein the semiconductor layer sequence comprises an active region configured to emit radiation with a peak emission wavelength in the near infrared spectral range . The semiconductor layer sequence comprises an absorber configured to at least partially absorb a shortwave radiation component of the radiation, wherein the absorber has a cutof f wavelength that is shorter than the peak emission wavelength .

[0013] By means of the absorber, the high energy tail of the emitted radiation can be limited or at least strongly suppressed . In particular, the absorber can be integrated into the semiconductor layer sequence so that external filters blocking the shortwave radiation component can be dispensed with .

[0014] In particular, the absorber can be produced from the same material system as the other layers of the semiconductor layer sequence , in particular the layers of the active region . According to at least one embodiment of the radiation emitting semiconductor device , the absorber is arranged within the active region . For example , the absorber is undoped or slightly doped . For example , a maximum doping concentration of the absorber is at most l * 1017 / cm3or at most 5* 1016 / cm3.

[0015] Electron hole pairs produced in the absorber by the absorption of the unintended shortwave component of the radiation can be recycled in the active region so that ef ficiency loses can be kept low, in particular compared to the case where a filter arranged downstream of the radiation emitting semiconductor device is used to block the shortwave radiation component of the radiation .

[0016] According to at least one embodiment of the radiation emitting semiconductor device , the absorber comprises a plurality of absorber layers that are spaced apart from one another . In particular, the absorber layers are spaced apart from one another when seen along a vertical direction ( i . e . a direction that extends perpendicular to a main extension direction of the layers of the semiconductor layer sequence . In other words , the absorptive material of the absorber is split into several portions when seen along a growth direction of the semiconductor layer sequence . The individual absorber layers may have the same thickness or at least partly di f fer from one another with respect to the thickness .

[0017] For example , the absorber comprises at least five or at least ten or at least twenty absorber layers and / or at most 200 or at most 100 absorber layers . Splitting the absorber into separate absorber layers may help to enhance recycling ef fects to improve the ef ficiency of the radiation emitting semiconductor device .

[0018] According to at least one embodiment of the radiation emitting semiconductor device , at least some of the absorber layers or all of the absorber layers have a thickness of at least 2 nm or at least 4 nm or at least 5 nm and / or at most 20 nm or at most 10 nm or at most 8 nm .

[0019] According to at least one embodiment of the radiation emitting semiconductor device , the absorber has or the absorber layers taken together have a thickness of at least 50 nm or at least 80 nm or at least 100 nm and / or at most 300 nm or at most 200 nm or at most 150 nm .

[0020] According to at least one embodiment of the radiation emitting semiconductor device , the active region comprises a plurality of quantum layers wherein a barrier layer is arranged between adj acent quantum layers . Thus , the active region comprises a multi quantum well structure (MQW) . Alternatively a single quantum layer may also be suf ficient . Thus , the active region may be formed as a single quantum well structure ( SQW) . Within a quantum layer, charge carriers undergo a quanti zation of their energy states by confinement .

[0021] According to at least one embodiment of the radiation emitting semiconductor device , at least one absorber layer is arranged between two adj acent quantum layers . Charge carriers produced in the absorber layer by absorption of the shortwave radiation component of the radiation produced by the active region can be trapped by the quantum layers and recombine there with the emission of radiation . Thus , the ef ficiency of the radiation emitting semiconductor device is improved .

[0022] For example , a bandgap of the absorber layer is smaller than a bandgap of the barrier layer . For example , the bandgap of the absorber layer is by at least 5 meV or at least 10 meV or at least 20 meV larger than the bandgap of the quantum layer .

[0023] Further, an electronic bandgap of the absorber layer may be larger than an electronic bandgap of the quantum layer, in particular larger than a transition energy between the ground state energy levels within the quantum well . For example , the bandgap of the absorber layer is by at least 20 meV or at least 50 meV or at least 100 meV larger than the bandgap of the quantum layer .

[0024] For example , the quantum layers are the only layers within the active region or within the entire semiconductor layer sequence that have a smaller bandgap than the absorber or the absorber layers .

[0025] According to at least one embodiment of the radiation emitting semiconductor device , at least one of the absorber layers is arranged between the quantum layer and the barrier layer . Thus , the absorber layer is arranged closer to the quantum layer than the barrier layer .

[0026] According to at least one embodiment of the radiation emitting semiconductor device , the absorber layer directly adj oins the quantum layer . This helps to enhance fast carrier relaxation of electron hole pairs produced in the absorber layer into the associated quantum layer . According to at least one embodiment of the radiation emitting semiconductor device , two absorber layers directly adj oin the same quantum layer on opposite sides of the quantum layer . In other words , the quantum layer is embedded between two absorber layers .

[0027] In particular, the number of absorber layers may be larger than the number of quantum layers within the active region .

[0028] According to at least one embodiment of the radiation emitting semiconductor device , an intermediate barrier layer is arranged between the absorber layer and the quantum layer located closest to the absorber layer . Thus , the absorber layer does not directly adj oin the closest quantum layer . In particular, the intermediate barrier layer may directly adj oin both the associated quantum layer and the associated absorber layer .

[0029] For example , a thickness of the intermediate barrier layer is at most 5 nm and / or at least 2 nm .

[0030] The intermediate barrier layer may have the same material composition as the barrier layer or a material composition di f ferent from the barrier layer . A comparably thin intermediate barrier layer may help to maintain the interface quality of the interfaces of the quantum layer and still allow ef ficient carrier recapture of absorbed electron hole pairs in the absorber layer into the quantum layer .

[0031] According to at least one embodiment of the radiation emitting semiconductor device , the absorber is arranged between the active region and a radiation exit area of the semiconductor body . In this case the absorber is located outside the active region .

[0032] For example , the absorber is a single absorber layer located within the first semiconductor layer or the second semiconductor layer .

[0033] According to at least one embodiment of the radiation emitting semiconductor device , the absorber has a doping concentration of at least 5* 1016 / cm3. In particular, the absorber may have a high doping concentration that is at least as high as the doping concentration of the directly adj oining semiconductor material , for example material of the first semiconductor layer .

[0034] By means of a comparably strongly doped absorber, forward voltage disadvantages may be avoided . Further, unintended radiative recombination within the absorber may be avoided by stimulating fast Auger processes by a high background carrier density .

[0035] The active region and / or the absorber and / or the entire semiconductor layer sequence may be based on the same semiconductor material system . For example , the active region and / or the absorber and / or the entire semiconductor layer sequence is based on arsenide compound semiconductor material .

[0036] The term "based on arsenide compound semiconductor material" means in the present context that the semiconductor material is a compound semiconductor material with arsenic as group V element , preferably comprising AlxInyGai-x-yAs or consisting thereof , where 0 < x < 1 , 0 < y < 1 , and x + y < 1 . The material does not necessarily have to have a mathematically exact composition according to the above formula. Rather, it may comprise, for example, one or more dopants as well as additional constituents. For the sake of simplicity, however, the above formula includes only the essential constituents of the crystal lattice (Al, Ga, In, As) , even if these may be partially replaced and / or supplemented by small amounts of other substances.

[0037] According to at least one embodiment of the radiation emitting semiconductor device, the absorber comprises AlxInyGai-x-yAs with 0 < x < 1, 0 < y < 1, and x + y < 1, in particular with 0 < x < 0.1 and 0 < y < 0.1.

[0038] According to at least one embodiment of the radiation emitting semiconductor device, the cutoff wavelength is at most 900 nm. If, for example, the peak emission wavelength is 940 nm, a cutoff wavelength of at most 900 nm, such as a cutoff wavelength of 850 nm, can be used to efficiently transmit the radiation to be emitted and to block the shortwave radiation component in the visible spectral range. If the peak emission wavelength is shorter, the cutoff wavelength may be reduced to a shorter wavelengths in order to avoid too strong absorption losses.

[0039] As radiation components with wavelengths shorter than 800 nm are efficiently reduced, the radiation emitting semiconductor device is particularly suited as a light source in a driver monitoring system or in any other application where shortwave components in the visible spectral range need to be avoided. At the same time, the peak emission wavelength can be short enough to ensure that the radiation can be efficiently detected by a silicon-based detector as silicon typically has a cutof f wavelength of about 1 . 1 pm .

[0040] Features described above in connection with at least one embodiment of the radiation emitting semiconductor device can be combined with other features described in connection with at least one embodiment of the radiation emitting semiconductor device unless they are contradictory .

[0041] Further configurations and expediencies will become apparent from the subsequent description of exemplary embodiments in connection with the figures .

[0042] In the exemplary embodiments and figures similar or similarly acting constituent parts are provided with the same reference signs . Generally, only the di f ferences with respect to the individual exemplary embodiments are described . Unless speci fied otherwise , the description of a part or feature in one exemplary embodiment applies to a corresponding part or feature in another exemplary embodiment as well .

[0043] In the Figures :

[0044] Figure 1A shows an exemplary embodiment of a radiation emitting semiconductor device in a cross-sectional view;

[0045] Figures IB, 1C, ID and IE show schematic band gap profiles of exemplary embodiments of an active region of a radiation emitting semiconductor device as illustrated in Figure 1A;

[0046] Figure 2A shows an exemplary embodiment of radiation emitting semiconductor device in a cross-sectional view; and Figure 2B schematically shows a schematic bandgap profile of a portion of the radiation emitting semiconductor device of Figure 2A.

[0047] The elements illustrated in the figures and their si ze relationships among one another are not necessarily true to scale . Rather, individual elements or layer thicknesses may be represented with an exaggerated si ze for the sake of better representability and / or for the sake of better understanding .

[0048] Figure 1A illustrates an exemplary embodiment of a radiation emitting semiconductor device 1 comprising a semiconductor body with a semiconductor layer sequence 2 . The semiconductor layer sequence 2 comprises an active region 20 configured to emit radiation with a peak emission wavelength in the near infrared spectral range . The semiconductor layer sequence 2 further comprises an absorber 3 configured to at least partially absorb a shortwave radiation component of the radiation emitted by the active region during operation of the radiation emitting semiconductor device 1 . The absorber 3 has a cutof f wavelength that is shorter than the peak emission wavelength .

[0049] The active region 20 is located between a first semiconductor layer 21 of a first conduction type and a second semiconductor layer 22 of a second conduction type di f ferent from the first conduction type so that the active region 20 is located in a pn-j unction .

[0050] For example , the first semiconductor layer 21 is n-conductive and the second semiconductor layer 22 is p-conductive or vice versa . Typically, the active region 20 , the first semiconductor layer 21 , and the second semiconductor layer 22 are formed from multiple layers .

[0051] Details of the active region are not explicitly shown in Figure 1A. As illustrated by means of a dotted line , the absorber 3 is arranged within the active region 20 in this exemplary embodiment .

[0052] Exemplary configurations of the active region 20 will be described below in connection with Figures IB to IE .

[0053] In the exemplary embodiment shown in Figure 1A, the radiation emitting semiconductor device 1 is embodied as a thin film chip where a growth substrate for the epitaxial growth of the semiconductor layer sequence 2 has been removed, so that it is not present in the finished device .

[0054] The semiconductor body with the semiconductor layer sequence 2 is arranged on a carrier 4 . The carrier 4 mechanically stabili zes the semiconductor layer sequence 2 so that the growth substrate is not required for this purpose .

[0055] For example , the semiconductor layer sequence 2 is connected to the carrier 4 by means of a connection layer 6 such as a solder layer or an in particular electrically conductive adhesive layer .

[0056] A mirror layer 7 is arranged on a side of the semiconductor body with the semiconductor layer sequence 2 that faces the carrier 4 . Radiation emitted in the active region 20 during operation of the radiation emitting semiconductor device 1 towards the carrier 4 may be reflected by the mirror layer 7 and exit from the semiconductor layer sequence 2 through a radiation exit area 25 that is formed on the side of the semiconductor layer sequence 2 that faces away from the carrier 4 .

[0057] The radiation emitting semiconductor device 1 further comprises a first contact 51 electrically connected to the first semiconductor layer sequence 21 and a second contact 52 connected to the second semiconductor layer 22 . By applying an external electrical voltage between the first contact 51 and the second contact 52 , charge carriers may be inj ected from opposite sides into the active region 20 to recombine there with the emission of radiation .

[0058] The active region 20 may comprise a multi quantum well structure with quantum layers 201 and barrier layers 202 arranged between adj acent quantum layers 201 . In the examples of Figures IB to IE , a schematic representation of a bandgap diagram is illustrated for a period 29 of the multi quantum well structure . The figures illustrate a conduction band edge 91 and a valence band edge 92 .

[0059] For example , the multi quantum well structure comprises at least two or at least five or at least ten and / or at most 50 or at most 30 periods 29 .

[0060] The quantum layers 201 are the layers of the semiconductor layer sequence 2 having the smallest bandgap .

[0061] The absorber 3 is split into a plurality of absorber layers 30 . For example , each period 29 of the multi quantum well structure comprises at least one absorber layer 30 . The bandgap of the absorber layer 30 is larger than the bandgap of the quantum layer 3 , in particular larger than a transition energy between the ground state energy levels 2010 schematically illustrated as hatched lines for the conduction band and for the valence band .

[0062] For example , the bandgap of the absorber layers 30 is by at least 20 meV or at least 50 meV or at least 100 meV larger than the bandgap of the quantum layers 201 .

[0063] Further, the bandgap of the absorber layers 30 is smaller than the bandgap of the barrier layers 202 . For example , the bandgap of the absorber layers 30 is by at least 10 meV or at least 20 meV or at least 50 meV smaller than the bandgap of the barrier layers 202 .

[0064] During operation of the radiation emitting semiconductor device , the shortwave radiation component of the radiation produced in the quantum layers 201 can be absorbed by the absorption layers 30 of the absorber 3 . The electron hole pairs generated in the absorber layers 30 by absorption of the shortwave component of the radiation can be trapped by the quantum layer 201 and recombine with emission of radiation again .

[0065] Thus , the ef ficiency of radiation emission can be increased, in particular compared to a device where the unintended shortwave radiation component of the radiation is absorbed by an optical component such as a filter that is arranged in a beam path downstream of the radiation emitting semiconductor device . For example , the cutof f wavelength of the absorber 3 may be 850 nm for an LED having a peak emission wavelength of 940 nm . I f the peak emission wavelength of the radiation emitting semiconductor device 1 is shorter, a shorter cutof f wavelength may also be used .

[0066] For example , GaAs can be used as material of the absorber 3 for a semiconductor layer sequence comprising InGaAs quantum layers 201 and AlGaAs barrier layers 202 . At room temperature , GaAs has a band gap of about 1 . 42 eV corresponding to a cutof f wavelength of about 870 nm . The cutof f wavelength can be reduced by adding aluminum to the absorber 3 , for instance with an aluminum content of at most 10% , or increased by adding indium to the absorber 3 , for instance with an indium content of at most 10% .

[0067] In particular, the absorber 3 may have the same lateral extent as the active region 20 and / or the radiation exit area 25 . Thus , an ef ficient absorption of the shortwave component over the entire area of the active region 20 and / or the radiation exit area 25 can be obtained .

[0068] In the exemplary embodiment of Figure IB, the absorber layer 30 directly adj oins the quantum layer 201 . In particular the absorber layer 30 follows the quantum layer 201 seen along a growth direction 27 during epitaxial growth of the semiconductor layer sequence 2 .

[0069] For example , the absorber layers 30 have a thickness along the growth direction 27 in a range from 5 nm to 10 nm .

[0070] In particular, the di f fusion length of the electron hole pairs produced within the absorber layer 30 may large enough for the electron hole pairs to reach the quantum layers 201 . Thus , ef ficient recycling processes can be obtained, where carriers produced in the absorber layer 30 may be trapped by the closest quantum well and radiatively recombine there .

[0071] Furthermore , the proximity of the entire material of the absorber layer 30 to the closest quantum layer 201 allows for a fast carrier relaxation into the quantum wells . This carrier relaxation helps to avoid non-intended radiative recombination within the absorber layer 30 .

[0072] The exemplary embodiment of Figure 1C essentially corresponds to that of Figure IB . In departure therefrom, the period 29 comprises two absorber layers 30 directly adj oining the quantum layer 201 on opposite sides of the quantum layer 201 . By means of this configuration, the number of absorber layers within the active region 20 can be increased while maintaining a high ef ficiency of recycling ef ficiency .

[0073] Consequently, the same overall thickness of absorber material can be obtained with smaller thicknesses of the individual absorber layers 30 . Alternatively, the overall thickness of the absorber material can be increased without having to increase the thickness of the individual absorber layers 30 .

[0074] The exemplary embodiment of Figure ID di f fers from the exemplary embodiment of Figure IB only with respect to the relative arrangement of the absorber 30 and the associated quantum layer 201 . In Figure ID, the absorber layer 30 has been grown prior to the closest quantum layer 201 .

[0075] The exemplary embodiment of Figure IE essentially corresponds to the exemplary embodiment of Figure IB . Unlike in Figure IB, the absorber layer 30 does not directly adj oin the closest quantum well 201 . An intermediate barrier layer 205 is arranged between the absorber layer 30 and the closest quantum layer 201 . The intermediate barrier layer 205 directly adj oins one quantum layer 201 and the absorber layer 30 closest to the quantum layer 201 .

[0076] Such an intermediate barrier layer 205 may be used to obtain a high interface quality of the quantum layer 201 . For example , the intermediate barrier layer 205 is formed from the same material as the barrier layer 202 .

[0077] For example , the intermediate barrier layer 205 has a thickness in a range from 1 nm to 5 nm . A comparably thin intermediate barrier layer 205 helps to increase the probability of electron hole pairs produced in the absorber layer 30 to reach the quantum layer 201 and recombine there with emission of radiation .

[0078] The intermediate barrier layer 205 illustrated in Figure IE may also be used in the exemplary embodiment of Figure ID or the exemplary embodiment of Figure 1C . In the exemplary embodiment of Figure 1C, the intermediate barrier layer 205 may be arranged on one side of the quantum layer 201 or on both sides of the quantum layer 201 .

[0079] In the exemplary embodiments of Figure IB to IE , the required total thickness of the absorber 3 can be split into a plurality of absorber layers 20 . For example , the absorber layers 30 taken together have a thickness of at least 50 nm or at least 80 nm or at least 100 nm and / or at most 300 nm or at most 200 nm or at most 150 nm . The absorber layers 30 can be arranged with respect to the quantum layers 201 such that photons absorbed in the absorber 30 produce electron hole pairs that may reach the quantum layers 201 and recombine there . Thus , the ef ficiency of the radiation emitting semiconductor device 1 is increased .

[0080] For example , the radiation emitting semiconductor device 1 may be embodied as a light-emitting diode emitting infrared radiation with a peak emission wavelength of at least 820 nm or at least 850 nm and / or at most 1 . 2 pm or at most 1 . 1 pm or at most 1 pm .

[0081] The entire semiconductor layer sequence 2 may be based on the same semiconductor material system . For example , the semiconductor layer sequence 2 is based on arsenide compound semiconductor material .

[0082] Forming the absorber 3 from the same material system as the quantum layers 201 allows for integration of the absorber 3 into the active region 20 without negatively af fecting the crystal quality of the quantum layers 201 .

[0083] However, the absorber 3 does not necessarily have to be located within the active region 20 .

[0084] Figures 2A and 2B illustrate an exemplary embodiment where the absorber 3 is located outside the active region 20 , for example in the first semiconductor layer 21 .

[0085] In this case , the absorber 3 may be a single layer having a suf ficient thickness . For example , the single layer may have a thickness of at least 80 nm and at most 200 nm . The absorber 3 is arranged on a side of the active region 20 that faces the radiation exit area 25 .

[0086] In this case , the absorber 3 may have the same doping concentration as or a higher doping concentration than the directly adj oining material of the first semiconductor layer 21 . This helps to avoid forward voltage disadvantages and to avoid radiative recombination within the absorber 3 by stimulating fast Auger processes by a high background carrier density .

[0087] Like in the previous embodiments , the absorber 3 may have the same lateral extent as the active region 20 and / or the radiation exit area 25 .

[0088] Consequently, the radiation generated in the active region 20 has to pass the absorber 3 on its way to the radiation exit area 25 .

[0089] An absorber 3 outside the active region 20 as described in connection with Figures 2A and 2B may also be combined with an absorber within the active region 20 as described in connection with Figures 1A to IE .

[0090] In the exemplary embodiments described above , an ef ficient suppression of shortwave radiation components visible to the human eye can be ef ficiently suppressed without signi ficant impact on the epitaxial growth time .

[0091] Further, the insertion of the absorber 3 does not require any additional process steps . Consequently, the performance of the radiation emitting semiconductor device can be improved in a cost-ef ficient manner . Further, the absorber does not have a signi ficant negative impact on the charge carrier transport properties within the semiconductor layer sequence 2 so that a high ef ficiency in light generation can be maintained .

[0092] This patent application claims the priority of German patent application 10 2024 113 924 . 2 , the disclosure content of which is hereby incorporated by reference . The invention described herein is not restricted by the description given with reference to the exemplary embodiments . Rather, the invention encompasses any novel feature and any combination of features , including in particular any combination of features in the claims , even i f this feature or this combination is not itsel f explicitly indicated in the claims or exemplary embodiments .

[0093] References

[0094] 1 radiation emitting semiconductor device

[0095] 2 semiconductor body with semiconductor layer sequence

[0096] 20 active region

[0097] 201 quantum layer

[0098] 2010 ground state energy level

[0099] 202 barrier layer

[0100] 205 intermediate barrier layer

[0101] 21 first semiconductor layer

[0102] 22 second semiconductor layer

[0103] 25 radiation exit area

[0104] 27 growth direction

[0105] 29 period

[0106] 3 absorber

[0107] 30 absorber layer

[0108] 4 carrier

[0109] 51 first contact

[0110] 52 second contact

[0111] 6 connection layer

[0112] 7 mirror layer

[0113] 8 arrow

[0114] 91 conduction band edge

[0115] 92 valence band edge

Claims

Claims1. A radiation emitting semiconductor device (1) comprising a semiconductor body with a semiconductor layer sequence (2) , wherein :- the semiconductor layer sequence (2) comprises an active region (20) configured to emit radiation with a peak emission wavelength in the near-infrared spectral range;- the semiconductor layer sequence (2) comprises an absorber(3) configured to at least partially absorb a shortwave radiation component of the radiation, the absorber (3) having a cut-off wavelength that is shorter than the peak emission wavelength .

2. The radiation emitting semiconductor device according to claim 1, wherein the absorber (3) is arranged within the active region (20) .

3. The radiation emitting semiconductor device according to claim 1 or 2, wherein the absorber (3) comprises a plurality of absorber layers (30) that are spaced apart from one another.

4. The radiation emitting semiconductor device according to claim 3, wherein at least some of the absorber layers (30) have a thickness of at least 2 nm and at most 10 nm.

5. The radiation emitting semiconductor device according to claim 3 or 4, wherein the absorber layers (30) taken together have a thickness of at least 50 nm.

6. The radiation emitting semiconductor device according to any one of claims 3 to 5, wherein the active region (20) comprises a plurality of quantum layers (201) , wherein a barrier layer (202) is arranged between adjacent quantum layers (201) .

7. The radiation emitting semiconductor device according to claim 6, wherein at least one absorber layer (30) is arranged between two adjacent quantum layers (201) .

8. The radiation emitting semiconductor device according to claim 6 or 7, wherein at least one of the absorber layers (30) is arranged between the quantum layer (201) and the barrier layer (202) .

9. The radiation emitting semiconductor device according to any one of claims 6 to 8, wherein the absorber layer (30) directly adjoins the quantum layer (201 ) .

10. The radiation emitting semiconductor device according to any one of claims 6 to 9, wherein two absorber layers (30) directly adjoin the same quantum layer (201) on opposite sides of the quantum layer (201) .

11. The radiation emitting semiconductor device according to any one of claims 6 to 9, wherein an intermediate barrier layer (205) is arranged between the absorber layer (30) and the quantum layer (201) located closest to the absorber layer (30) .

12. The radiation emitting semiconductor device according to claim 1, wherein the absorber (3) is arranged between the active region (20) and a radiation exit area (25) of the semiconductor body.

13. The radiation emitting semiconductor device according to claim 12, wherein the absorber (3) has a doping concentration of at least 5 * 1016cm-3.

14. The radiation emitting semiconductor device according to any one of the preceding claims, wherein the absorber (3) comprises AlxInyGai-x-yAs with 0 < x < 0.1 and 0 < y < 0.1.

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