Unit integrating a light emitter and a sensor, display and method for producing a display

Abstract

A unit for integrated light emitter and sensor for a display, comprising: a thin film photodiode detector, TFPD, comprising a film with an upper side and a lower side configured to absorb light and convert the absorbed light into an electric current; a first thin film light emitting diode, TFLED, comprising a film with an upper side and a lower side configured to convert an electric current into light; a backplane voltage regulation circuit comprising a first and a second TFPD contact, a first TFLED contact and a transistor, wherein the transistor is configured to set the potential of the first TFLED contact and to set the potential of the two TFPD contacts or to measure the potential difference between the two TFPD contacts; wherein the lower side of the film of the first TFLED is electrically connected to the first TFLED contact, and wherein the lower side of the film of the TFPD is electrically connected to the first TFPD contact and the upper side of the film of the TFPD is electrically connected to the second TFPD contact.

Description

TECHNICAL FIELD

[0001] The present invention relates to a unit of integrated light emitter and sensor, a display and a method for producing a display. BACKGROUND

[0002] A display can comprise light emitting diodes arranged to form pixels in which an image can be displayed. By incorporating photodiodes in the display, the display can both present an image and detect objects in the vicinity of the display. This can allow for example to integrate a fingerprint sensor in the display such that a fingerprint can be detected when a finger is pressed against the display. An example of a display with integrated photodiodes is described for example by Akkerman et al. in [Large-area Optical Fingerprint Sensors for Next Generation Smartphones, SID Symposium Digest of Technical Papers. 2019; 50(1): 1000-1003]. Akkerman describes a light detector under a partially transparent display. Light from the display can be reflected from a finger on the display and a light detector array under the display can detect the reflected light. Thereby, light can travel through the display to reach the light detector array. To suppress light scattering when light travels through the display, an optical collimator is placed between the display and the light detector array. SUMMARY

[0003] It is an object of the present invention to enable a display with integrated photodiodes. It is a further object of the present invention to enable an economic production of said display. It is a further object of the present invention to enable an accurate detection of a pattern in the vicinity of the display by the photodiodes. These and other objects of the present invention are at least partially met by the invention as defined in the independent claims.

[0004] According to a first aspect of the present invention, a unit of integrated light emitter and sensor for a display is provided, the unit of integrated light emitter and sensor comprising:

[0005] a thin film photodiode detector (TFPD) comprising a film having an upper side and a lower side, the film being configured to absorb light and to convert the absorbed light into an electrical current;

[0006] a first thin film light emitting diode (TFLED) comprising a film having an upper side and a lower side, the film being configured to convert an electrical current into light;

[0007] a backplane voltage regulation circuit comprising a first and a second TFPD contact, a first TFLED contact and a transistor, wherein the transistor is configured to set the potential of the first TFLED contact and to set the potential of the two TFPD contacts or to measure the potential difference between the two TFPD contacts;

[0008] wherein the lower side of the film of the first TFLED is electrically connected to the first TFLED contact, and wherein the lower side of the film of the TFPD is electrically connected to the first TFPD contact and the upper side of the film of the TFPD is electrically connected to the second TFPD contact.

[0009] The unit of integrated light emitter and sensor for a display can be part of a pixel of the display. The first TFLED can emit light which together with light from other pixels forms an image.

[0010] The light emitted by the first TFLED can also be reflected by an object in the vicinity of the display back to the TFPD. The TFPD can thus be configured to detect the reflected light originating from the first TFLED. Thereby, the TFPD allows for detection of an object in the vicinity of the display.

[0011] The presence of an object, such as a finger, can be detected using one or more units of integrated light emitter and sensor. Alternatively or additionally, a pattern of an object, such as a fingerprint of a finger, can be recorded using a plurality of units of integrated light emitter and sensor. The output, i.e. the voltage or the current, of the TFPD from different pixels can be used to form an image of an object in the vicinity of the display. In the following, as an example, the object will generally be described as a finger, e.g. a finger pressing on the display. However, it should be understood that the object can also be a palm, a document or another object. Thereby, it should be understood that reasoning also applies to detection of another object or recording of a pattern of another object whenever a finger detection or a finger fingerprint recording is mentioned.

[0012] An advantage of the unit of integrated light emitter and sensor is that it enables accurate detection of an object in the vicinity of the unit of integrated light emitter and sensor. Since the first and the second TFPD contact, the first TFLED contact and the transistor can all be comprised in a common backplane voltage regulation circuit, these circuit elements can be arranged underneath the TFPD and the first TFLED. The voltage regulation circuit can thus be arranged in such a way with respect to the TFPD and the first TFLED that occlusion of light travelling from the first TFLED to an object and back to the TFPD can be avoided.

[0013] Because both the underside of the film of the TFPD and the underside of the film of the first TFLED are electrically connected to the same backplane voltage regulation circuit, the TFPD and the first TFLED can be arranged side-by-side, i.e. arranged so as not to overlap or shadow each other as seen along the light propagation path from the first TFLED to the reflective object and back to the TFPD. Thereby, light can travel from the first TFLED to the object and back to the TFPD without being scattered or shadowed. This can facilitate accurate detection of objects in the vicinity of the integrated light emitter and sensor unit.

[0014] Conversely, if the underside of the film of the TFPD and the underside of the film of the first TFLED were electrically connected to different backplane voltage regulation circuits arranged in different planes, side-by-side arrangement of the TFPD and the first TFLED would be difficult to achieve. For example, Akkerman describes an arrangement in which organic photodiodes (OPDs) are arranged underneath an organic light emitting diode (OLED) display. In such an arrangement, light reflected by an object can need to pass through the OLED display and the circuitry associated with the OLED display (e.g. the backplane associated with the OLED display) on its way to the OPD. The light can be scattered as it passes through the OLED display and the circuitry associated with the OLED display, which can reduce the light detected by the OPD and thereby also reduce the signal-to-noise ratio.

[0015] Furthermore, because the top side of the film of the TFPD is also electrically connected to the backplane voltage regulation circuit, the TFPD can be controlled separately via the first and second TFPD contact faces. Thereby, the driving of the TFPD can be decoupled from the driving of the first TFLED. The TFPD need not share any electrical contacts with the first TFLED (or any other TFLED of the integrated light emitter and sensor unit or display). For example, the electrical potential of the top and underside of the film of the TFPD can be set to any value suitable for operating the TFPD independently of the first TFLED. Conversely, if the TFPD and the first TFLED shared electrical contacts, it can be necessary to set the electrical potential of the shared contacts to a value that would be a compromise between the optimal driving of the TFPD and the optimal driving of the first TFLED. Decoupling the driving of the TFPD from the driving of the first TFLED can be particularly advantageous because the TFPD and the first TFLED can be operated at different polarities, e.g. the TFPD is reverse biased and the first TFLED is forward biased. By decoupling the driving of the TFPD from the driving of the first TFLED, noise in the signal detected by the TFPD can be reduced. This can further improve the accuracy of the detection of objects in the vicinity of the integrated light emitter and sensor unit.

[0016] Another advantage is that the unit integrating the light emitter and the sensor can be produced at low cost. When both the TFPD and the first TFLED utilize the same unit integrating the light emitter and the sensor, the process required to generate the unit integrating the light emitter and the sensor can be less, which can facilitate cost savings.

[0017] Furthermore, as facilitated by the present application, when the light scattering along the light path from the first TFLED to the object and back to the TFPD is low, it can not be necessary to use any additional means for reducing the scattering. For example, in the display described by Akkerman, the effect of light scattering on the signal detected by the photodiode is suppressed using an optical collimator. Producing this collimator is expensive, as it can include a small hole requiring an advanced process.

[0018] The TFPD or the TFLED can include a thin film. The lateral extension of the thin film can be greater than the thickness of the thin film. The thickness can range from 1 nanometer to 10 micrometers. However, in some embodiments, the thickness can also be greater, for example ranging from 1 nanometer to 100 micrometers.

[0019] The first TFLED can for example include a light emitting layer between an electron transport layer and a hole transport layer. The light emitting layer can be an electroluminescent layer. Electrons can be transported from the electron transport layer to the light emitting layer. Similarly, holes can be transported from the hole transport layer to the light emitting layer. The electrons and holes can recombine in the light emitting layer to form light, thereby converting electrical current into light. The light emitting layer can include an organic semiconductor. Thereby, the first TFLED can be an organic light emitting diode (OLED). The light emitting layer can alternatively include quantum dots, which are semiconductor nanocrystals. The light emitting layer can alternatively be a perovskite material film.

[0020] The TFPD can for example include a light absorbing layer between an electron transport layer and a hole transport layer. The light absorbing layer can be referred to as an active layer. The light absorbing layer can absorb light and generate electron-hole pairs. The electron-hole pairs can for example be separated by a built-in potential. The electrons can be transported away by the electron transport layer. The holes can be transported away by the hole transport layer. Thereby, the absorbed light can be converted into electrical current. The electrical current can be measured to form a representation of the amount of light that has been absorbed. Thereby, the TFPD can operate in a photoconductive mode. It is noted that if there is no closed circuit between the electron transport layer and the hole transport layer, the generated charge carriers can cause a potential difference. The potential difference can be measured to form a representation of the amount of light that has been absorbed. Thereby, the TFPD can operate in a photovoltaic mode.

[0021] The light absorbing layer can include an organic semiconductor. Thereby, the first TFLED can be an organic photodiode (OPD). The light absorbing layer can alternatively include quantum dots. The light absorbing layer can alternatively be a perovskite material film.

[0022] The materials of the light emitting layer of the TFPD and the light absorbing layer of the TFPD can have a band gap. The band gap of the light emitting layer can define the wavelength of light emitted. The band gap of the light absorbing layer can define the longest wavelength of light that the light absorbing layer is capable of absorbing. The band gap of the light emitting layer of the first TFLED can be greater than the band gap of the light absorbing layer of the TFPD.

[0023] The TFPD can be configured such that the electron transport layer of the TFPD abuts the upper side of the TFPD, while the hole transport layer abuts the lower side of the TFPD. However, the opposite arrangement is also possible, in which the electron transport layer of the TFPD abuts the lower side of the TFPD, while the hole transport layer abuts the upper side of the TFPD.

[0024] The first TFLED can be configured such that the electron transport layer of the first TFLED abuts the upper side of the first TFLED, while the hole transport layer abuts the lower side of the first TFLED. However, the opposite arrangement is also possible, in which the electron transport layer of the first TFLED abuts the lower side of the first TFLED, while the hole transport layer abuts the upper side of the first TFLED.

[0025] The TFPD and the first TFLED can be configured such that the electron transport layer of the TFPD and the electron transport layer of the first TFLED abut the same side of their respective thin films, for example both abut the upper side of their respective thin films. However, the TFPD and the first TFLED can be configured such that the electron transport layer of the TFPD and the electron transport layer of the first TFLED abut opposite sides of their respective thin films, for example the electron transport layer of the TFPD abuts the upper side of the TFPD, while the electron transport layer of the first TFLED abuts the lower side of the first TFLED, or vice versa.

[0026] The thin film of the first TFLED can be at least partially located in the same plane as the thin film of the TFPD. However, it will be appreciated that the thin films can be flexible. As such, they can not necessarily form a plane. The unit of integrated light emitter and sensor can have a nominal shape, for example a shape in which it is produced or a shape to which it reverts when not subject to any external forces. The unit of integrated light emitter and sensor can be configured such that the thin film of the first TFLED is located in the same plane as the thin film of the TFPD when the unit of integrated light emitter and sensor is in its nominal shape.

[0027] The backplane voltage regulating circuit can for example be a thin film transistor (TFT) backplane. The first and second TFPD contact surfaces and the first TFLED contact surface can be electrically conductive surfaces, for example metal surfaces, on the backplane voltage regulating circuit, which are connected to transistors of the backplane voltage regulating circuit. Since the lower side of the membrane of the TFPD is electrically connected to the first TFPD contact surface and the upper side of the membrane of the TFPD is electrically connected to the second TFPD contact surface, a potential difference between the lower and upper side of the membrane of the TFPD can be set or measured via the first and second TFPD contact surfaces. By setting the potential difference between the lower and upper side of the membrane of the TFPD such that the TFPD is reverse biased, the TFPD can operate in photoconductive mode, i.e. the light absorbed by the TFPD can be measured as an electrical current. The light absorbed by the TFPD can alternatively be measured as a potential difference between the lower and upper side of the membrane of the TFPD, i.e. the TFPD can operate in photovoltaic mode.

[0028] Since the lower side of the membrane of the first TFLED is electrically connected to the first TFLED contact surface, the potential of the lower side of the membrane of the first TFLED can be set via the first TFLED contact surface. The potential of the lower side of the membrane of the first TFLED can be set relative to the potential of the upper side of the membrane of the first TFLED such that a potential difference between the lower and upper side of the membrane of the first TFLED can be controlled. The potential difference can be set such that the first TFLED is forward biased and thereby emits light.

[0029] The first TFLED and the TFPD of the unit integrating a light emitter and a sensor can be arranged on top of the backplane voltage regulating circuit. Thereby, the first TFLED and the TFPD can be arranged on the same side of the voltage regulating circuit. This can ensure that the optical path from the first TFLED to the object and from the object to the TFPD is not placed through components which substantially scatter light. The first TFLED and the TFPD can for example be arranged side by side on top of the backplane voltage regulating circuit. The first TFLED and the TFPD can for example be arranged at least partially side by side in the same plane on top of the backplane voltage regulating circuit.

[0030] The unit integrating a light emitter and a sensor can further comprise:

[0031] a bottom TFPD contact protruding from the first TFPD contact surface and electrically connecting the first TFPD contact surface with the lower side of the membrane of the TFPD; and

[0032] a top TFPD contact structure comprising a lower contact portion protruding from the second TFPD contact surface and an upper contact portion extending laterally from the lower contact portion to a position above the upper side of the membrane of the TFPD and connecting with the upper side of the membrane of the TFPD, thereby electrically connecting the upper side of the membrane of the TFPD to the second TFPD contact surface via the upper and lower contact portions.

[0033] Thus, the top TFPD contact structure can access the second TFPD contact surface and electrically connect it to the upper side of the membrane of the TFPD, even if the second TFPD contact surface is located under the TFPD. With the bottom TFPD contact and the top TFPD contact structure, the potential of the lower and upper side of the membrane of the TFPD can be controlled from the backplane voltage regulation circuit.

[0034] Furthermore, the top TFPD contact structure can protect the TFPD during device production: between TFPD membrane deposition and TFPLED membrane deposition, a cleaning step can be required, for example a plasma cleaning. The top TFPD contact structure can cover the TFPD so that it does not degrade during this cleaning. This protection can contribute to a high quality TFPD, for example a TFPD with low leakage current. This protection can additionally or alternatively contribute to a low cost production process, as the need for other protection means can be low. The top TFPD contact structure can protect the TFPD itself or as part of a protective shield during other production processes, the protective shield comprising the top TFPD contact structure and a thin film barrier layer of electrically insulating material (for example SiN or AI2O3). Thus, the top TFPD contact structure and the thin film barrier layer can cover the TFPD so that it does not degrade during cleaning.

[0035] The bottom TFPD contact and the top TFPD contact structure can be made of any conductive material, such as a metal, indium tin oxide (ITO), MoCr, indium gallium zinc oxide (IGZO). The bottom TFPD contact and the top TFPD contact structure can not necessarily be made of the same material.

[0036] At least a portion of the bottom TFPD contact can be reflective. Thus, light that passes through the TFPD without being absorbed can be reflected back so that it can be absorbed on a second pass through the TFPD. The material of the bottom TFPD contact can be, for example, ITO / Ag / ITO, MoCr, ITO, IGZO, IGZO / Ag / ITO, etc.

[0037] The upper contact of the top TFPD contact structure can be at least partially transparent to light of a wavelength that can be detected by the TFPD. Thus, the portion of the upper side of the membrane of the TFPD that is covered by the upper contact of the top TFPD contact structure can still receive detectable light. Thus, the detected signal can be high, which can improve the signal-to-noise ratio and enable accurate detection of objects in the vicinity of the integrated light emitter and sensor cell. The material of the upper contact of the top TFPD contact structure can be, for example, ITO, indium zinc oxide (IZO), aluminum zinc oxide (AZO), a conductive polymer such as PEDOT, PSS, or a thin metal layer such as 10 nm Ag or less than 20 nm Mg:Ag alloy in a ratio of 10:1, etc.

[0038] The unit of integrated light emitter and sensor can further comprise:

[0039] a bottom TFLED contact electrically connecting the first TFLED contact surface with the lower side of the membrane of the first TFLED; and

[0040] a top TFLED contact structure comprising an upper contact portion, wherein the upper side of the membrane of the first TFLED is electrically connected to the upper contact portion of the top TFLED contact structure.

[0041] By the bottom TFLED contact and the top TFLED contact structure, the electrical potential of the lower side and the upper side of the membrane of the first TFLED can be controlled. The electrical potential of the lower side of the membrane of the first TFLED can be controlled from the first TFLED contact surface. The electrical potential of the upper side of the membrane of the first TFLED can be controlled via the top TFLED contact structure.

[0042] The upper contact portion of the top TFLED contact structure can be at least partially transparent for light emitted by the first TFLED. Thereby, the upper contact portion of the top TFLED contact structure can at least not completely obstruct light from underneath the first TFLED. This can result in a large amount of light transmission, which in turn can result in a large amount of light being reflected by an object and detected by the TFPD. Thereby, the detected signal can be high, which can improve the signal-to-noise ratio and enable accurate detection of an object in the vicinity of the unit of integrated light emitter and sensor.

[0043] The upper contact portion of the top TFLED contact structure can be at least partially transparent for light of a wavelength that can be detected by the TFPD. Thereby, the upper contact portion of the top TFLED contact structure can extend above the TFPD and still allow light transmission to the TFPD. Thereby, the upper contact portion of the top TFLED contact structure can be produced in a simple and economic way. The upper contact portion of the top TFLED contact structure can for example be a part of a common and partially lenticular top TFLED contact structure shared by several units of integrated light emitter and sensor of the display.

[0044] The upper contact portion of the top TFPD contact structure can be closer to the backplane voltage regulation circuitry than the upper contact portion of the top TFLED contact structure. Thereby, the top TFLED contact structure can extend above the upper contact portion of the top TFPD contact structure without interfering with the upper contact portion of the top TFPD contact structure. This can facilitate providing a common top TFLED contact structure shared by several units of integrated light emitter and sensor of the display.

[0045] The backplane voltage regulating circuit can be configured to turn on the TFPD by applying a first voltage between the upper side and the lower side of the membrane of the TFPD via the top and bottom TFPD contact structures. The first voltage can be a voltage that reverse biases the TFPD. Thereby, the TFPD can operate in a photoconductive mode.

[0046] Alternatively, the TFPD can be operated in a photovoltaic mode by configuring the backplane voltage regulating circuit to measure the voltage between the upper side and the lower side of the membrane of the TFPD via the top and bottom TFPD contact structures.

[0047] The unit of integrated light emitter and sensor can further comprise:

[0048] a second TFPD comprising a membrane having an upper side and a lower side, the membrane being configured to absorb light and convert the absorbed light into an electrical current.

[0049] wherein the backplane voltage regulating circuit further comprises a second TFPD contact structure, and wherein the transistor of the backplane voltage regulating circuit is further configured to set the potential of the second TFPD contact face.

[0050] The unit of integrated light emitter and sensor comprising more than one TFPLED can enable a display to have good image display properties and / or good object detection properties. Several TFPLEDs can for example increase the intensity of the emitted light.

[0051] The first and second TFPLEDs can be configured to emit light having different spectra. Thereby, the unit of integrated light emitter and sensor can emit different colors. The image display properties can thereby be improved. Color images, for example RGB images, can be displayed. Furthermore, the object detection properties can also be improved. One TFPLED can be used to emit light related to displaying an image on the display, while another TFPLED can be dedicated to detecting objects in the vicinity of the display. The wavelength of the other TFPLED can for example be configured to give high reflectivity or low absorption or scattering of the expected objects in the upper contact of the top TFPD contact structure or the upper contact of the top TFPLED contact structure. Both the first and the second TFPLEDs can emit light in the visible range. Alternatively, at least one of the first and second TFPLEDs can emit light outside the visible range.

[0052] The unit of integrated light emitter and sensor can further comprise:

[0053] a second TFPD comprising a membrane having an upper side and a lower side, the membrane being configured to absorb light and convert the absorbed light into an electrical current.

[0054] The unit of integrated light emitter and sensor comprising more than one TFPD can enable the display to have good object detection properties. For example, one TFPD can detect one color, while another TFPD can detect another color. This can enable, for example, measuring the relative reflectivity of objects of different colors.

[0055] The second TFPD can be connected to third and fourth contact pads on the backplane voltage regulation circuit in a similar way as the TFPD is connected to the first and second TFPD contact pads. Alternatively, the TFPD and the second TFPD can share one contact pad. For example, the top TFPD contact structure can electrically connect both the upper side of the membrane of the TFPD and the upper side of the membrane of the second TFPD to the second TFPD contact pad on the backplane voltage regulation circuit.

[0056] According to a second aspect of the present invention, there is provided a display comprising an array of pixel regions, at least some of the pixel regions comprising a respective unit of integrated light emitter and sensor configured according to the first aspect,

[0057] wherein the units of integrated light emitter and sensor of the display share a common backplane voltage regulation circuit, and

[0058] wherein, within each respective pixel region of the units of integrated light emitter and sensor, the first TFPD contact pad, the second TFPD contact pad and the first TFPLED contact pad of each unit of integrated light emitter and sensor are included in the common backplane voltage regulation circuit.

[0059] The display according to the second aspect can record a pattern or image of an object near the display, for example a pattern or image of a fingerprint of a finger pressing the display.

[0060] In some embodiments, all pixels comprise a unit of integrated light emitter and sensor configured according to the first aspect. In other embodiments, only some of the pixels of the display comprise a unit of integrated light emitter and sensor configured according to the first aspect. For example, some pixels can comprise only a TFPLED, while some pixels comprise both a TFPLED and a TFPD according to the first aspect. The resolution of the pattern recording can not necessarily be as high as the resolution of displaying images. It should also be understood that in certain parts of the display, there can be a higher density of units of integrated light emitter and sensor configured according to the first aspect than in other parts of the display. One area of the display can for example be dedicated to fingerprint recognition. For example, the bottom of a mobile phone display where the home button is typically located can be dedicated to fingerprint recognition and comprise a high density of units of integrated light emitter and sensor configured according to the first aspect.

[0061] The common backplane voltage regulating circuit can be a TFT backplane extending under the TFLEDs and the TFPDs of the display. A display with a common backplane voltage regulating circuit controlling the potential of the upper side and the lower side of the TFPDs and the lower side of the TFLEDs can have several advantages, as discussed in connection with the first aspect above.

[0062] In addition, the second aspect facilitates that the TFPDs and the TFLEDs are arranged side by side or at least partly in the same plane on the common backplane voltage regulating circuit. This can ensure that there are no components in a pixel area that scatter or obstruct light along the light path from the TFLED of said pixel area to the object and further to the TFPD of said pixel area. This can also ensure that light that should be reflected by the object to the TFPD of a particular pixel is not scattered towards the TFPD of another pixel. Scattering of light from one pixel to another pixel can reduce the resolution of the recorded pattern of the object. Thereby, the second aspect provides a display that can accurately record the pattern of an object in the vicinity of the display.

[0063] Furthermore, the second aspect facilitates that each TFPD is controlled individually, since each TFPD of the unit of integrated light emitter and sensor has its own first and second TFPD contact. When the TFPD of one pixel area does not share a contact with the TFPD of another pixel area, TFPD noise and cross-talk between TFPDs can be reduced. This can also facilitate accurate recording of the pattern of an object in the vicinity of the display.

[0064] In addition, the second aspect enables economical production of the display. When all TFPDs and all TFLEDs form part of the common backplane voltage regulating circuit, the number of procedures in the production can be reduced. For example, the display can not need to be assembled from two separate backplanes, one for the TFPDs and one for the TFLEDs.

[0065] The upper contact of the TFLED connected to the array can form part of a common top TFLED contact structure. Thereby, the upper contact of the top TFLED can be produced in a simple and economical way. One large, partly transparent, common top TFLED contact structure can be shared by several or all units of integrated light emitter and sensor of the display.

[0066] The common top TFLED contact structure can further comprise a lower contact. The lower contact can protrude from the common TFLED contact of the backplane voltage regulating circuit to electrically connect the upper contact of the top TFLED contact structure to the TFLED contact. The backplane voltage regulating circuit, e.g. transistors thereof, can be configured to set the potential of the first TFLED contact of each unit of integrated light emitter and sensor and to set the potential of the common TFLED contact. The backplane voltage regulating circuit can thus provide a forward bias driving voltage to the TFLEDs.

[0067] The display can be configured to turn on a TFLED of a pixel area by applying a second voltage between the upper side and the lower side of the film of the TFLED via the common top TFLED contact structure and the bottom TFLED contact of the TFLED. The TFLED of a pixel area can be turned on by setting the second voltage such that the TFLED is forward biased. The intensity of the light emitted from the TFLED can be increased by increasing the forward bias.

[0068] According to a third aspect of the present invention, there is provided a method for producing an intermediate product of a display, the method comprising:

[0069] providing a backplane voltage regulating circuit comprising an array of pixel areas, wherein the backplane voltage regulating circuit comprises, in at least some of the pixel areas, first and second TFPD contact faces and a first TFLED contact face, the backplane voltage regulating circuit further comprising a transistor, wherein the transistor is configured to set the potential of the first TFLED contact face and to set the potential of the two TFPD contact faces or to measure the potential between the two TFPD contact faces;

[0070] forming, within the at least some of the pixel areas:

[0071] a bottom TFPD contact piece protruding from the first TFPD contact face,

[0072] a lower contact portion protruding from the second TFPD contact face, and

[0073] a bottom TFLED contact piece protruding from the first TFLED contact face;

[0074] forming, within the at least some of the pixel areas, a thin film photodiode detector (TFPD) on top of and in electrical contact with the bottom TFPD contact piece, the TFPD comprising a film having an upper side and a lower side, the film being configured to absorb light and to convert the absorbed light into an electrical current; and

[0075] forming, within the at least some of the pixel areas, an upper contact portion extending laterally from the lower contact portion to a position above the upper side of the film of the TFPD and in electrical contact with the upper side of the film of the TFPD, whereby the upper contact portion and the lower contact portion form a top TFPD contact structure electrically connecting the upper side of the film of the TFPD to the second TFPD contact face.

[0076] The intermediate product of a display can be a product in which at least some of the pixel areas have been provided with a TFPD and have been prepared such that a first TFLED can be provided in a subsequent production process.

[0077] The backplane voltage regulating circuit can be provided as an off-the-shelf component. The backplane voltage regulating circuit can also be manufactured as part of the production method.

[0078] Forming the bottom TFPD contact, the lower contact, or the bottom TFLED contact can be done by, for example, depositing an electrically conductive material by evaporation or sputtering. The bottom TFPD contact, the lower contact, and the bottom TFLED contact in one pixel area or in several pixel areas can be deposited simultaneously. The deposition can be done in more than one process, for example, a first deposition of one material and a second deposition of another material. The last deposition or the last few depositions before the TFPD is formed can form the reflective part of the contact or the contact part.

[0079] The bottom TFLED contact can not necessarily be formed only in the at least some pixel areas. The backplane voltage regulation circuit can comprise the first TFLED contact face in each pixel area, i.e. not only in the at least some pixel areas. Thereby, in each pixel area, a bottom TFLED contact protruding from the first TFLED contact face can subsequently be formed. The TFPD can be formed on the bottom TFPD contact by depositing a plurality of layers on the bottom TFPD contact, wherein the plurality of layers form a thin film. The electron transport layer can be deposited on the bottom TFPD contact, followed by the light absorbing layer, and then the hole transport layer. Alternatively, the hole transport layer can be deposited on the bottom TFPD contact, followed by the light absorbing layer, and then the electron transport layer. The deposition can be done by vacuum deposition or solution processing such as slot die coating, spin coating, inkjet printing, or screen printing.

[0080] The upper contact extending laterally from the lower contact to a position above the upper side of the film of the TFPD can be formed by depositing an electrically conductive material, for example by evaporation or sputtering once the TFPD has been formed. The upper contact can be made of a material that is at least partially transparent for light of a wavelength that can be detected by the TFPD. The upper contact in one pixel area or in several pixel areas can be deposited simultaneously.

[0081] This method of producing a display can be an economic production method. Here, all TFPDs can be formed on a common backplane voltage regulation circuit. Furthermore, the bottom TFLED contact can be prepared such that a TFLED can be formed on the same common backplane voltage regulation circuit during other production processes. The other production processes can be the same production processes used for producing a display without a TFPD. Thereby, after performing the method according to the third aspect, additional processes can be completed to complete the display. The additional processes can be completed in the same production facility or at another production facility, for example, a production facility that handles TFLEDs but not TFPDs.

[0082] The additional processes can further comprise:

[0083] a first thin-film photodiode (TFPD) formed within each pixel region and electrically connected to the bottom TFPD contact, the first TFPD comprising a film having an upper side and a lower side, the film configured to convert electrical current into light; and

[0084] a common top TFPD contact structure formed electrically connected to the upper side of the film of the first TFPD of the array of pixel regions.

[0085] The first TFPD can be formed on the bottom TFPD contact by depositing a plurality of layers on the bottom TFPD contact, wherein the plurality of layers form a thin film. An electron transport layer can be deposited on the bottom TFPD contact, followed by a light emitting layer, and then a hole transport layer. Alternatively, a hole transport layer can be deposited on the bottom TFPD contact, followed by a light emitting layer, and then an electron transport layer.

[0086] The common top TFPD contact structure can be formed by depositing a conductive material, for example by evaporation or sputtering once the TFPD has been formed. The common top TFPD contact structure can be made of a material that is at least partially transparent to light emitted by the first TFPD and / or at least partially transparent to wavelengths of light that can be detected by the TFPD.

[0087] A display produced according to the third aspect of the application can have the same or similar advantages as a display according to the second aspect.

[0088] BRIEF DESCRIPTION OF DRAWINGS

[0089] The above and other objects, features and advantages of the inventive concept will be better understood through the following illustrative and non-limiting detailed description taken in conjunction with the accompanying drawings. In the drawings, similar reference numerals will be used to refer to similar elements throughout.

[0090] Figure 1a is a cross-sectional view of a unit integrating a light emitter and a sensor.

[0091] Figure 1b is a top view of a unit integrating a light emitter and a sensor.

[0092] Figure 2 is a cross-sectional view of a unit integrating a light emitter and a sensor.

[0093] Figure 3 is a top view of a display.

[0094] Figure 4 is a flowchart of a method for producing a display. DETAILED DESCRIPTION

[0095] A detailed description of integrated light emitter and sensor cells and displays, in conjunction with the appended drawings, follows. The aspects of the inventive concept can be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; the present disclosure is not limited to the disclosed embodiments; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the inventive concept to those skilled in the art. It should be noted that the relative sizes of the illustrated elements, such as the relative thicknesses of layers, are merely schematic and can differ from actual physical structures, which can be made for illustrative purposes. In the drawings, directions X and Y can be used to indicate first and second horizontal directions, respectively, while direction Z can be used to indicate a vertical direction. Directional qualifiers, such as "horizontal" and "vertical", should thus be understood with respect to a local frame of reference of the sensor cell or display. More specifically, a horizontal direction or orientation can be understood as a direction or orientation parallel to a main extension plane of a planar structure or layer of the structural arrangement or display (e.g., of the backplane regulation circuit discussed below). A vertical direction or orientation can thus be understood as a direction or orientation perpendicular to the main extension plane / upper surface of the backplane regulation circuit. As can be understood, terms such as "above", "over", "below", "on", "under", "top", and the like should be understood as relative positions viewed in the vertical direction.

[0096] Figure 1a is a schematic cross-sectional view of an integrated light emitter and sensor cell 2. The integrated light emitter and sensor cell 2 comprises a TFPD 5 as well as a first TFLED 10. As this drawing represents a schematic view, the different components can not necessarily be drawn to scale. In particular, the thickness of the TFPD 5 and the first TFLED 10 can be smaller relative to their lateral extension than their appearance in this drawing.

[0097] The TFPD 5 comprises a film 6 having a lower side or surface 7 as well as an upper side or surface 8. Figure 1a The film 6 of the TFPD 5 in comprises a light absorbing layer 74 between an electron transport layer 72 and a hole transport layer 78. The light absorbing layer 74 can for example comprise an organic semiconductor, quantum dots or perovskite. For example, the TFPD 5 can have a PbS quantum dot light absorbing layer that absorbs light having a wavelength shorter than 2000 pm.

[0098] The first TFLED 10 comprises a film 16 having a lower side or surface 17 as well as an upper side or surface 18. Figure 1a The film 16 of the first TFLED 10 in comprises a light emitting layer 76 between an electron transport layer 72 and a hole transport layer 78. The light emitting layer 76 can for example comprise an organic semiconductor, quantum dots or perovskite. For example, the first TFLED 10 can have a green-emitting Ir(ppy)3 light emitting layer 76.

[0099] The organic semiconductor can be a small-molecule organic semiconductor or a polymer semiconductor. Examples of quantum dots suitable for the TFPD 5 or the first TFLED 10 are cadmium selenide quantum dots, indium phosphide quantum dots, lead sulfide quantum dots, and silicon quantum dots.

[0100] The first TFLED 10 and the TFPD 5 are arranged on a backplane voltage regulation circuit 30. The backplane voltage regulation circuit 30 can be a TFT backplane. The backplane voltage regulation circuit 30 comprises a first TFPD contact face 31, a second TFPD contact face 32, and a first TFLED contact face 41. As shown, the contact faces 31, 32, 41 can form part of an upper surface 30a of the backplane voltage regulation circuit 30. Further, the backplane voltage regulation circuit 30 comprises transistors (not shown) configured to set the potential of the first TFLED contact face 41 and to set the potential of the two TFPD contact faces 31, 32 or to measure the potential difference between the two TFPD contact faces 31, 32.

[0101] The bottom TFPD contact 34 protrudes from the first TFPD contact face 31 through an opening in the first electrically insulating layer 61 and electrically contacts the first TFPD contact face 31 with the lower side 7 of the film 6 of the TFPD 5.

[0102] The top TFPD contact structure 36 electrically connects the upper side 8 of the film 6 of the TFPD 5 to the second TFPD contact face 32. The top TFPD contact structure 36 comprises a lower contact portion 37 which protrudes from the second TFPD contact face 32 through an opening in the first electrically insulating layer 61. The top TFPD contact structure 36 further comprises an upper contact portion 38 which extends laterally from the lower contact portion 37 to a position on the upper side 8 of the film 6 of the TFPD 5 and electrically connects with the upper side 8 of the film 6 of the TFPD 5. The top TFPD contact structure 36 can be at least partially transparent for light of a wavelength which can be detected by the TFPD 5.

[0103] The bottom TFLED contact 44 electrically connects the first TFLED contact face with the lower side 17 of the film 16 of the first TFLED 10.

[0104] The top TFLED contact structure 46 comprises an upper contact portion 48, wherein the upper side 18 of the film 16 of the first TFLED 10 is electrically connected to the upper contact portion 48 of the top TFLED contact structure 36.

[0105] In Figure 1aIn the embodiment shown in Fig. 1, the top TFLED contact structure 36 is closer to the backplane voltage regulation circuit 30 than the top contact 48 of the top TFLED contact structure 46. Thereby, the top TFLED contact structure 46 is located above the top TFPD contact structure 36. The TFPD 5 and the top TFPD contact structure 36 upper contact 38 can be embedded in a second electrically insulating layer 62 such that the top TFLED contact structure 46 is not electrically connected to the TFPD 5.

[0106] The top TFLED contact structure 46 upper contact 48 can be at least partially transparent to the light emitted by the first TFLED 10. The top TFLED contact structure 46 upper contact 48 can also be at least partially transparent to the wavelengths of light that can be detected by the TFPD 5, as shown in Fig. 1. Thereby, the top TFLED contact structure 46 upper contact 48 can not severely degrade the light emission of the first TFLED 10 or the light detection of the TFPD 5. However, the application is not limited to this and the top TFLED contact structure 46 upper contact 48 can be patterned such that it does not extend laterally over the TFPD 5 (not shown in the figures). Thereby, the top TFLED contact structure 46 upper contact 48 does not obstruct the detection of light by the TFPD 5. This can result in a large amount of light being detected by the TFPD. Thereby, the detected signal can be high, which can improve the signal to noise ratio and enable accurate detection of objects in the vicinity of the integrated light emitter and sensor unit. The patterning of the upper contact 48 can be done, for example, during deposition by lithography or by using a shadow mask. Figure 1a

[0107] There can be a third electrically insulating layer 63 on the top TFLED contact structure 46 upper contact 48, which insulates the top TFLED contact structure 46 upper contact 48 from the surroundings of the integrated light emitter and sensor unit 2.

[0108] The first, second and third electrically insulating layers 61, 62, 63 can be made of, for example, SiN, Si02or AI2O3. The first, second and third electrically insulating layers 61, 62, 63 can be made of different materials. The first, second and third electrically insulating layers 61, 62, 63 can be deposited using, for example, plasma enhanced chemical vapor deposition or atomic layer deposition.

[0109] Figure 1b is a partially transparent top view of certain features in the integrated light emitter and sensor unit 2. Figure 1b The integrated light emitter and sensor unit 2 of Fig. 1 and Figure 1a The integrated light emitter and sensor unit 2 of Fig. 1 and the integrated light emitter and sensor unit 2 of Fig. 2 can be the same integrated light emitter and sensor unit 2. Figure 1b ​The partial transparency of the TFPD 5 and the first TFLED 10 can be for illustration purposes only. However, in embodiments of the application, some features can in fact be partially transparent, as will be discussed further.

[0110] Figure 1b The integrated light emitter and sensor unit 2 has a backplane voltage regulation circuit 30 disposed under the bottom, i.e., the TFPD 5 and the first TFLED 10. The bottom TFPD contact 34, the lower contact 37 of the top TFPD contact structure 36, and the bottom TFLED contact 44 protrude from the backplane voltage regulation circuit 30.

[0111] The TFPD 5 is located over the bottom TFPD contact 34. In this figure, the bottom TFPD contact 34 only adjoins a central portion of the lower surface of the TFPD 5. In other embodiments, the bottom TFPD contact 34 can adjoin a substantial portion of the entire lower surface of the TFPD 5. This can facilitate the collection of created charge carriers.

[0112] The first TFLED 10 is located over the bottom TFLED contact 44. In this figure, the bottom TFLED contact 44 only adjoins a central portion of the lower surface of the first TFLED 10. In other embodiments, the bottom TFLED contact 44 can adjoin a substantial portion of the entire lower surface of the first TFLED 10.

[0113] The upper contact 38 of the top TFPD contact structure 36 extends laterally from the lower contact 37 (and is connected to the upper side 8 of the membrane 6 of the TFPD 5, as shown in Figure 1a In this figure, the upper contact 38 only partially covers the TFPD 5. In other embodiments, the upper contact 38 can completely cover the TFPD 5.

[0114] The upper contact 48 of the top TFLED contact structure 46 extends over the first TFLED 10 (and is electrically connected to the upper side 18 of the membrane 16 of the first TFLED 10, as shown in Figure 1a As seen in this figure, the upper contact 48 of the top TFLED contact structure 46 can extend not only over the first TFLED 10 but also over the TFPD 5. However, the application is not limited to this, and the upper contact 48 of the top TFLED contact structure 46 can be patterned so that it does not laterally extend over the TFPD 5. The upper contact 48 of the top TFLED contact structure 46 can laterally extend away from the TFPD 5 and the first TFLED 10 and be connected to a potential elsewhere, e.g., an additional TFLED contact surface of the backplane voltage regulation circuit area located outside the illustrated area of the integrated light emitter and sensor unit 2.

[0115] Figure 2is a schematic cross-sectional view of a unit 2 of an integrated light emitter and sensor. Figure 2 The unit 2 of an integrated light emitter and sensor of Fig. 2 comprises the same features as the unit 2 of an integrated light emitter and sensor of Fig. 1. In addition, Figure 1a The unit 2 of an integrated light emitter and sensor of Fig. 2 comprises the same features as the unit 2 of an integrated light emitter and sensor of Fig. 1. In addition, Figure 2 The unit 2 of an integrated light emitter and sensor of Fig. 2 comprises a second TFLED 20. As this figure represents a schematic drawing, the different components can not necessarily be drawn to scale. In particular, the thickness of the TFPD 5, the first TFLED 10 and the second TFLED 20 can be smaller relative to their lateral extension than their appearance in this figure.

[0116] Similar to the first TFLED 10, the second TFLED 20 comprises a film 26 having a lower side 27 and an upper side 28. The film 26 of the second TFLED 20 can comprise multiple layers, for example an electron transport layer, a light emitting layer and a hole transport layer. The light emitting layer can for example comprise an organic semiconductor, quantum dots or perovskite. In Figure 2 In Fig. 2, the backplane voltage regulation circuit 30 comprises a second TFLED contact 42 in addition to the first TFLED contact 41 and the first and second TFPD contacts 31, 32.

[0117] The first TFLED 10 and the second TFLED 20 can be configured to emit light having different spectra. For example, the first TFLED 10 can have an ir(ppy)3 light emitting layer emitting green light, while the second TFLED 20 can have an Eu(dbm)3(phen) light emitting layer emitting red light.

[0118] Figure 3 A (partially transparent) top view of a display 1 is shown. The display 1 comprises an array 50 of pixel areas 51. The pixel areas 51 can be arranged in multiple rows and multiple columns. For example, the direction X can correspond to the row direction, while the direction Y can correspond to the column direction. Some of the pixel areas 51 comprise a unit 2 of an integrated light emitter and sensor similar to the unit 2 of an integrated light emitter and sensor shown in Fig. 1. In the shown display 1, half of the pixel areas 51 comprise a unit 2 of an integrated light emitter and sensor. However, the portion of the pixel areas 51 comprising a unit 2 of an integrated light emitter and sensor can be different in different embodiments. For example, all of the pixel areas 51 can comprise a unit 2 of an integrated light emitter and sensor, or a quarter of the pixel areas 51 can comprise a unit 2 of an integrated light emitter and sensor. In this figure, the pixel areas lacking a unit 2 of an integrated light emitter and sensor instead comprise a first TFLED 10.

[0119] In this figure, the integrated light emitter and sensor cells 2 of the display 1 share a common backplane voltage regulation circuit 30. That is, the first TFPD contact surface 31, the second TFPD contact surface 32 and the first TFLED contact surface 41 of each integrated light emitter and sensor cell 2 within each pixel region 51 form part of an upper surface 30a (e.g. can be a TFT plane) of the backplane voltage regulation circuit 30. Furthermore, the integrated light emitter and sensor cells 2 of the display 1 share a common top TFLED contact structure 46 comprising upper contact portions 48 which are electrically connected to the TFLEDs of the integrated light emitter and sensor cells 2, as well as to the TFLEDs of pixels of the display 1 which lack an integrated light emitter and sensor cell 2, as described in combination with Figure 1a The common top TFLED contact structure 46 and the common upper contact portions 48 can also be electrically connected to the TFLEDs of pixels of the display 1 which lack an integrated light emitter and sensor cell 2. In addition to the upper contact portions 48, the common top TFLED contact structure 46 can have lower contact portions 49 which electrically connect the upper contact portions 48 to the common backplane voltage regulation circuit 30. The backplane voltage regulation circuit 30 can for example comprise a common TFLED contact surface 52. The contact surface 52 can form part of the upper surface 30a of the backplane voltage regulation circuit 30. The contact surface 52 can for example be arranged in a peripheral region of the backplane voltage regulation circuit 30 or at a suitable location within the array 50. The lower contact portions 49 can protrude from the contact surface 52 to electrically connect the upper contact portions 48 to the TFLED contact surface 52. Thereby, the common backplane voltage regulation circuit 30 can simultaneously set the potential of the upper side of all TFLEDs of the integrated light emitter and sensor cells 2.

[0120] Figure 4 A flow chart of a method 100 for producing the display 1 is shown.

[0121] The method 100 comprises providing S102 a backplane voltage regulation circuit 30. The backplane voltage regulation circuit 30 can be divided into pixel regions 51 forming the array 50, wherein each pixel region 51 represents a region of the backplane voltage regulation circuit 30 within which a pixel is formed. At least some of the pixel regions 51 can be dedicated to integrated light emitter and sensor cells 2. In such pixel regions 51, the backplane voltage regulation circuit 30 comprises the first TFPD contact surface 31 and the second TFPD contact surface 32 as well as the first TFLED contact surface 41. In some embodiments, the pixel regions 51 of the backplane voltage regulation circuit 30 can also comprise the second TFLED contact surface 42.

[0122] The method 100 further comprises forming S104 a bottom TFPD contact 34 protruding from the first TFPD contact surface 31 within said at least some pixel areas 51 ; forming S106 a lower contact 37 protruding from the second TFPD contact surface 32; and forming S108 a bottom TFLED contact 44 protruding from the first TFLED contact surface 41. The forming S104, S106, S108 of the contacts can be done simultaneously by depositing a first electrically insulating layer 61 on the backplane voltage regulation circuit 30, creating openings (e.g. by lithography and etching) in the first electrically insulating layer 61 on the first TFPD contact surface 31 and the second TFPD contact surface 32 and the first TFLED contact surface 41, after which the contacts can be formed (e.g. evaporated) into the openings. The first electrically insulating layer 61 can be a sandwich layer.

[0123] The method 100 further comprises forming S110 a TFPD 5 on the bottom TFPD contact 34 within said at least some pixel areas 51. A pixel defining layer (e.g. SiN, Si02, AI2O3) can be deposited on the first insulating layer 61 and openings can be formed (e.g. by etching at lithographically defined locations) through this pixel defining layer at locations corresponding to the bottom TFPD contact 34.

[0124] In a first embodiment of the method 100, the openings through the pixel defining layer at locations corresponding to the lower contact 37 of the top TFPD contact structure 36 are formed simultaneously with the openings at the bottom TFPD contact 34.

[0125] In a second embodiment of the method 100, the openings through the pixel defining layer at locations corresponding to the lower contact 37 of the top TFPD contact structure 36 and at locations corresponding to the bottom TFLED contact 44 are formed simultaneously with the openings at the bottom TFPD contact 34.

[0126] After the openings at locations corresponding to the bottom TFPD contact 34 are formed, the TFPD 5 can be deposited into the openings, for example by depositing an electron transport layer, then a light absorbing layer, and subsequently a hole transport layer, so that these three layers form the thin film 6. Deposition into the other openings (e.g. the openings corresponding to the lower contact 37 of the top TFPD contact structure 36 or the openings corresponding to the bottom TFLED contact 44) can be avoided by protecting these openings with photoresist and lithographically defining the deposition area only on the bottom TFPD contact 34.

[0127] The method 100 further comprises forming S112 an upper contact 38 within said at least some pixel areas, the upper contact 38 extending laterally from the lower contact 37 to a position on an upper side of the membrane of the TFPD 5 and being in electrical contact with the upper side of the membrane 6 of the TFPD 5. The upper contact 38 can be deposited, e.g. by evaporation, and the lateral extension of the upper contact 38 can be defined by photolithography.

[0128] After forming S112 the upper contact 38, a thin film barrier layer, e.g. SiN, Si02, AI203, can be deposited, which thin film barrier layer and the pixel defining layer can together form a second electrically insulating layer 62 in which the upper contact 38 is embedded. Thereby, the thin film barrier layer can electrically insulate the upper contact 38 from components deposited on the thin film barrier layer.

[0129] An optional additional step of the method 100 can be forming S114 a first TFLED 10 on a bottom TFLED contact 44 within said at least some pixel areas. An opening can be formed through the thin film barrier layer at a position corresponding to the bottom TFLED contact 44. The opening can also be formed through the pixel defining layer, unless this has not been done (as in the second embodiment of the method). Once the opening is formed, the first TFLED 10 can be deposited into the opening, e.g. by deposition of an electron transport layer, then a light emitting layer, and subsequently a hole transport layer, such that these three layers form a thin film 16. The position of the first TFLED 10 on the bottom TFLED contact 44 can be defined by a photolithography process.

[0130] Another optional additional step of the method 100 can be forming S116 a common top TFLED contact structure 46 electrically connected to the upper side of the membrane 16 of the first TFLED 10 of the array of pixel areas. The common top TFLED contact structure 46 can be evaporated onto the previously formed structure, for example. The common top TFLED contact structure 46 can be separated from the upper contact 38 of the top TFPD contact structure 36 by the previously described thin film barrier layer.

[0131] In the foregoing, the inventive concept has mainly been described with reference to a limited number of examples. However, it will be readily appreciated that other examples than the ones disclosed above are equally possible within the scope of the inventive concept, as defined by the appended claims.

Claims

1. A unit (2) integrating a light emitter and a sensor for a display (1), the unit (2) comprising: A thin-film photodiode detector (TFPD) (5) includes a film (6) having an upper side (8) and a lower side (7), the film (6) being configured to absorb light and convert the absorbed light into an electric current; A first thin-film light-emitting diode (TFLED) (10) includes a film (16) having an upper side (18) and a lower side (17), the film (16) being configured to convert current into light; The backplane voltage regulation circuit (30) includes a first TFPD contact surface (31) and a second TFPD contact surface (32), a first TFLED contact surface (41) and a transistor, wherein the transistor is configured to set the potential of the first TFLED contact surface (41) and set the potential of the two TFPD contact surfaces (31, 32) or measure the potential difference between the two TFPD contact surfaces (31, 32); Bottom TFPD contact (34) protrudes from the first TFPD contact surface (31) and electrically connects the first TFPD contact surface (31) to the lower side (7) of the membrane (6) of the TFPD (5); as well as A top TFPD contact structure (36) includes a lower contact portion (37) and an upper contact portion (38). The lower contact portion (37) protrudes from the second TFPD contact surface (32), and the upper contact portion (38) of the top TFPD contact structure (36) extends laterally from the lower contact portion (37) to a position above the upper side of the film (6) of the TFPD (5) and connects to the upper side (8) of the film (6) of the TFPD (5). Thus, the upper side (8) of the film (6) of the TFPD (5) is electrically connected to the second TFPD contact surface (32) via the upper contact portion (38) and the lower contact portion (37) of the top TFPD contact structure (36). The lower side (17) of the film (16) of the first TFLED (10) is electrically connected to the first TFLED contact surface (41), and the lower side (7) of the film (6) of the TFPD (5) is electrically connected to the first TFPD contact surface (31), and the upper side (8) of the film (6) of the TFPD (5) is electrically connected to the second TFPD contact surface (32).

2. The unit (2) integrating the light emitter and sensor as claimed in claim 1, wherein the first TFLED (10) and the TFPD (5) are arranged on the backplane voltage regulation circuit (30).

3. The unit (2) integrating the light emitter and sensor as described in claim 1, further comprising: A bottom TFLED contact (44) electrically connects the first TFLED contact surface (41) to the lower side (17) of the film (16) of the first TFLED (10); and The top TFLED contact structure (46) includes an upper contact portion (48), wherein the upper side (18) of the film (16) of the first TFLED (10) is electrically connected to the upper contact portion (48) of the top TFLED contact structure (46).

4. The unit (2) of the integrated light emitter and sensor as claimed in claim 1, wherein the backplane voltage regulation circuit (30) is configured to turn on the TFPD (5) by applying a first voltage between the upper and lower sides (7) of the membrane (6) of the TFPD (5) via the top TFPD contact structure and the bottom TFPD contact structure.

5. The unit (2) integrating a light emitter and a sensor as claimed in claim 1, wherein the unit (2) integrating a light emitter and a sensor further comprises: The second TFLED (20) includes a film (26) having an upper side (28) and a lower side (27), the film (26) being configured to convert current into light; The backplane voltage regulation circuit (30) further includes a second TFLED contact surface (42), and the transistor of the backplane voltage regulation circuit (30) is further configured to set the potential of the second TFLED contact surface (42).

6. The unit (2) of the integrated light emitter and sensor as claimed in claim 5, wherein the first TFLED (10) and the second TFLED (20) are configured to emit light with different spectra.

7. A display (1) comprising an array (50) of pixel regions (51), wherein at least some pixel regions (51) include a unit (2) of a corresponding integrated light emitter and sensor configured according to claim 1. The integrated light emitter and sensor unit (2) of the display (1) share a common backplane voltage regulation circuit, and In the corresponding pixel area (51) of each integrated light emitter and sensor unit (2), the first TFPD contact surface (31), the second TFPD contact surface (32) and the first TFLED contact surface (41) of each integrated light emitter and sensor unit (2) are included in the common backplane voltage regulation circuit.

8. The display (1) of claim 7, wherein the display (1) is configured to turn on the TFLED by applying a second voltage between the upper and lower sides of the film of the TFLED via a top TFLED contact structure (46) and a bottom TFLED contact of a TFLED in a pixel region (51).

9. A method (100) for producing an intermediate product of a display (1), the method (100) comprising: A backplane voltage regulation circuit (30) is provided, comprising an array (50) of pixel regions (51), wherein the backplane voltage regulation circuit (30) includes a first TFPD contact surface (31) and a second TFPD contact surface (32) and a first TFLED contact surface (41) in at least some of the pixel regions (51), and the backplane voltage regulation circuit (30) further includes a transistor, wherein the transistor is configured to set the potential of the first TFLED contact surface (41) and set the potential of the two TFPD contact surfaces or measure the potential between the two TFPD contact surfaces; Formed within the at least some pixel regions (51) (S104, S106, S108): The bottom TFPD contact (34) protrudes from the first TFPD contact surface (31). The lower contact portion (37) protruding from the second TFPD contact surface (32), and Bottom TFLED contact (44) protruding from the first TFLED contact surface (41); A thin-film photodiode detector TFPD (5) is formed (S110) in the at least some pixel regions (51) above and in electrical contact with the bottom TFPD contact (34), the TFPD (5) including a film (6) having an upper side (8) and a lower side (7), the film (6) being configured to absorb light and convert the absorbed light into an electric current; as well as An upper contact portion (38) is formed (S112) within the at least some pixel areas (51). The upper contact portion (38) extends laterally from the lower contact portion (37) to a position above the upper side (8) of the film (6) of the TFPD (5) and makes electrical contact with the upper side (8) of the film (6) of the TFPD (5). Thus, the upper contact portion (38) and the lower contact portion (37) form a top TFPD contact structure (36) that electrically connects the upper side (8) of the film (6) of the TFPD (5) to the second TFPD contact surface.

Images