TWI702405B - Photosensitive thin film transistor and electromagnetic wave detection device - Google Patents

Abstract

A photosensitive thin film transistor and an electromagnetic wave detection device. The photosensitive thin film transistor is formed on a substrate and includes a gate electrode, an insulating layer, a channel layer, a drain metal electrode, and a source metal electrode. The gate electrode includes a gate metal electrode and a CIS-based gate p-type semiconductor layer, the gate p-type semiconductor layer is CuIn _x Ga _(1-x) Se _y S _(1-y) , x and y are both It is any real number from 0 to 1, and the gate p-type semiconductor layer also functions as a first light absorbing layer. The channel layer is n-type ZnO or n-type ITO, and has the function of the second light absorption layer. The p-type gate semiconductor layer improves the spectral response of near-infrared light, the channel layer improves the spectral response of ultraviolet light, and the photosensitive thin film transistor has a simple structure and is easy to manufacture.

Description

Photosensitive thin film transistor and electromagnetic wave detection device

The invention relates to a thin film transistor and an electromagnetic wave detection device, in particular to a photosensitive thin film transistor and an electromagnetic wave detection device used for sensing incident electromagnetic waves with a wavelength range of less than 2.5 μm.

Electromagnetic wave detection devices in the visible light band have been widely used in consumer electronic products, such as the camera lens module of a smart phone. The sensor in it is a complementary metal oxide semiconductor (CMOS) image detection device. Based on the production process of silicon wafer integrated circuits, PN junction photodiode array (Photodiode Array) sensing elements driven and scanned based on crystalline silicon CMOS circuits are manufactured. The production of CMOS photodiode arrays is compatible with the manufacturing process of silicon integrated circuits, and has many advantages such as low cost, low power loss, high scanning rate, and wide spectral response.

In addition, after the completion of the CMOS photodiode array manufacturing process, red, blue, and green color filters can be arranged on the respective photodiode sensing pixels, as well as microlenses and other components, with external Digital image processing circuit to achieve low noise, multi-color grayscale, and high resolution characteristics. Therefore, driven by strong market demand, CMOS image detection devices have been widely used in digital cameras, smart phones, computer network camera modules, and IoT sensors.

The above-mentioned crystalline silicon CMOS photodiode array is mainly used in the sensing technology of visible light imaging. For the ultraviolet light band less than 400nm, crystalline silicon has no good spectral response essentially. In addition, crystalline silicon material has a spectral response in the near-infrared light band from 700nm to 1100nm. However, in order to avoid infrared light noise from interfering with visible light imaging, conventional technology will configure infrared in the camera lens module of the CMOS image detection device Optical filter to filter infrared light noise with wavelength greater than 700nm. In fact, because the crystalline silicon material belongs to the indirect band gap (Indirect Band Gap) semiconductor, the thickness of the PN junction photodiode based on crystalline silicon must be thicker to absorb more photon energy; however, it also allows The carriers excited by near-infrared light are more likely to recombine electrons and holes in the thicker diode structure.

Therefore, the photodiode of crystalline silicon in the 700nm to 1100nm wavelength band is limited by the surface carrier binding, fewer carrier transitions, and light reflection from the incident window layer (light-receiving surface). It is inherently difficult to apply in near Electromagnetic wave detection in infrared light band. In recent years, although back-facing CMOS image sensors have changed to amorphous silicon PIN photodiodes, the function of the photodiode can be realized by a thinner PIN thickness (approximately 2μm); however, amorphous silicon is only used in visible light. The band has a spectral response, so it is not suitable for electromagnetic wave detection applications in the near-infrared light band.

Sensing in the near-infrared light band can be applied to technologies such as organic molecular detection and biomedical detection. In the application of organic molecular detection, it is possible to detect the ingredients and content in the diet through the detection of near-infrared light band; in the biomedical detection, it is used in the detection of blood oxygen and the positioning of fluorescent cursor targets.

In the application of biomedical testing, the panel-type electromagnetic wave detection device is helpful for the full-view image reconstruction of a test object. Take Taiwan Patent Certificate No. I415283, I496277, I500926, I570425 and other 4 patents as examples. These patents record X-ray flat panel detectors, which are based on thin film transistors (TFT) driving and scanning amorphous silicon PIN photodiode arrays. Realize planar X-ray sensing. Since the spectral response of amorphous silicon is only in the visible light band, a wavelength conversion film (such as cesium iodide film) must be placed on the light-receiving surface of the PIN photodiode array, which can convert the X-rays that have passed through the object to the visible light band Therefore, it is realized that the X-ray image is incident on the PIN photodiode array with a visible light signal, and the two-dimensional overall view of the X-ray image of the object to be measured is reconstructed through the driving and scanning of the TFT and the external digital image processing circuit. In the past ten years, this type of X-ray flat panel detection device quickly replaced the conventional X-ray film shooting, and then became a popular medical detection equipment.

However, due to the relatively low photoelectric conversion efficiency of the amorphous silicon PIN photodiode, it is not suitable to additionally dispose a phase modulation film on the light-receiving surface of the flat-panel device, which makes the flat-panel detection device applied to biomedical inspections and cannot yet provide The three-dimensional image information of the measured object, and its image resolution is still limited by the line width of the TFT process, and the phase modulation cannot be used to improve its resolution.

Moreover, compared with the structure of crystalline silicon PN diode, the built-in electric field of the amorphous silicon PIN photodiode is very weak, and the amorphous silicon film contains too many dangling bonds, which makes non-crystalline silicon The photoelectric conversion efficiency of crystalline silicon PIN is difficult to exceed 8%, and the phenomenon that the efficiency deteriorates after multiple illuminations (Staebler-Wronski Effect); also because of the low photoelectric conversion efficiency of amorphous silicon PIN photodiodes On the light-receiving surface of this type of flat electromagnetic wave detection device, it is not suitable to configure filters or wavelength conversion films that affect the amount of light transmission, so the application range of amorphous silicon PIN light diodes is limited.

In addition, the manufacturing process based on TFT driving and scanning amorphous silicon PIN photodiode array is quite complicated, and more than 12 masks are required in the manufacturing process. In response to the huge market demand for biomedical sensing, how to simplify the sensor pixel structure in the array and maintain the high photoelectric conversion efficiency of the sensor pixels in order to accurately reconstruct the image from ultraviolet light to near-infrared light with high resolution The whole picture is a very important subject.

Therefore, for sensing pixel arrays and electromagnetic wave detection devices with a wavelength range of less than 2.5μm (including ultraviolet light, visible light, and near-infrared light wavelengths), at least the following points must be improved: (1) Improvements to ultraviolet light and near-infrared light (2) Simplify the manufacturing process and realize large-area full-view electromagnetic wave detection through appropriate structural improvements; (3) Improve the photoelectric conversion efficiency of the sensing pixel array, so that even if additional phases are set on the detection device Modulation components, or wavelength modulation components such as filters and wavelength conversion films, can still maintain the sensitivity required by the detection function.

Therefore, the purpose of the present invention is to provide a photosensitive thin film transistor and electromagnetic wave detection device that can overcome at least one of the disadvantages of the prior art.

Therefore, the photosensitive thin film transistor of the present invention is formed on a substrate, and includes a gate electrode, an insulating layer, a channel layer, a drain metal electrode on the channel layer, and a drain metal electrode on the channel layer The source metal electrode above and spaced from the drain metal electrode.

The gate electrode sequentially includes a gate metal electrode and a gate p-type semiconductor layer from being adjacent to and away from the substrate. The gate p-type semiconductor layer is CuIn _x Ga _(1-x) Se _y S _{(1- y)} , where x is any real number from 0 to 1, and y is any real number from 0 to 1, and the gate p-type semiconductor layer also functions as the first light absorbing layer.

The insulating layer is located above the gate p-type semiconductor layer, and the insulating layer is SiO ₂ or Si ₃ N ₄ . The channel layer is located above the insulating layer, the channel layer is n-type ZnO or n-type ITO, and has the function of a second light absorption layer, and the light absorption band of the channel layer is different from that of the gate p-type semiconductor layer Light absorption band.

The electromagnetic wave detection device of the present invention includes a substrate and a thin film array unit formed on the substrate. The thin film array unit includes a backlight surface facing the substrate, a light-receiving surface opposite to the backlight surface, and MxN sensing pixels, where M and N are both positive integers, and each sensing pixel includes the above The photosensitive thin film transistor is used for scanning drive and data transmission, as well as for detecting electromagnetic wave signals.

The effect of the present invention is that the CIS-based gate p-type semiconductor layer of the photosensitive thin film transistor has the function of the first light absorbing layer to improve the near-infrared light spectral response of the thin film array unit, and by The channel layer of n-ZnO or n-ITO also has the function of the second light absorption layer, which improves the UV spectrum response of the thin film array unit, thereby enhancing the overall photoelectric conversion efficiency. In addition, the photosensitive thin film transistor has the functions of scanning driving, data transmission and electromagnetic wave signal detection, which greatly simplifies the structure of the sensing pixel, makes the thin film array unit easy to manufacture, and can realize large-area full-view electromagnetic wave detection. Furthermore, because the present invention improves the photoelectric conversion efficiency, even if a phase modulation unit or a wavelength modulation unit is additionally arranged on the light-receiving surface of the thin film array unit, the detection sensitivity will not be affected. The variable unit realizes three-dimensional information or high-resolution image reconstruction, and realizes the wavelength multiplexing function of the electromagnetic wave detection device through the wavelength modulation unit.

Before the present invention is described in detail, it should be noted that in the following description, similar elements are represented by the same numbers.

Referring to FIGS. 1 and 2, a first embodiment of the electromagnetic wave detection device of the present invention includes a substrate 1 and a thin film array unit 2 formed on the substrate 1.

The substrate 1 is, for example, but not limited to, a glass substrate, a metal foil flexible substrate, a polyethylene terephthalate (PET), or a polyimide (PI) flexible substrate.

The thin film array unit 2 is formed on the substrate 1, and includes a backlight surface 21 facing the substrate 1, a light receiving surface 22 opposite to the backlight surface 21, and M×N sensing pixels 3, where M, N All are positive integers. The backlight surface 21 and the light receiving surface 22 are formed by matching the top surface and the bottom surface of the sensing pixels 3. Preferably, the electromagnetic wave wavelength range that can be detected by the thin film array unit 2 includes ultraviolet light, visible light, and near-infrared light.

2 and 3, the MxN sensing pixels 3 are arranged in an array, the N sensing pixels 3 in the mth column share a gate drive line 301, and the M sensing pixels 3 in the nth row share a common gate drive line 301. For a data scan line 302, the m is any positive integer from 1 to M, and n is any positive integer from 1 to N.

Each sensing pixel 3 includes a photosensitive thin film transistor (TFT) 4, such as a photosensitive field effect transistor (FET), and includes a gate, a source, and a drain. The photosensitive thin film transistor 4 is controlled by the gate drive line 301, and the drain is connected to the data scan line 302 shared by the pixel array. The source is connected to an operating bias line shared by all M×N sensing pixels 3. The equivalent circuit diagram of a single sensing pixel 3 shown in FIG. 3 is only an embodiment of the present invention, and the scope of implementation of the present invention cannot be limited by this. For example, a single sensing pixel 3 may also include several non-photosensitive types. Thin film transistors, to realize the signal amplification function inside the sensing pixel 3, or additional resistors and capacitors in consideration of the timing of external digital signal processing, are still within the scope of the present invention.

Referring to FIG. 4, the film layer stack structure of the photosensitive thin film transistor 4 in the form of field effect transistors will be described, including a gate electrode 41 formed on the substrate 1, and an insulating layer located above the gate electrode 41 Layer 42, a channel layer 43 located above the insulating layer 42, and a drain metal electrode 44 and a source metal electrode 45 located on the channel layer 43.

The gate electrode 41 includes a gate metal electrode 411 and a gate p-type semiconductor layer 412 in sequence from being adjacent to and away from the substrate 1. The gate metal electrode 411 may be metallic molybdenum (Mo), or a single-layer or multi-layer structure mainly composed of molybdenum alloy. The gate p-type semiconductor layer 412 is made of copper indium selenium (CIS)-based material, and in addition to the function of a gate electrode, it also has the function of a first light absorption layer. The copper indium selenium material may be a ternary or quaternary compound film formed of copper, indium, gallium, and selenium. For example, the gate p-type semiconductor layer 412 may include copper indium selenium, or copper indium gallium selenium, or Copper gallium selenium, the film thickness is about 0.5μm to 1.5μm. The material of the gate p-type semiconductor layer 412 is represented by a chemical formula: CuIn _x Ga _(1-x) Se _y S _(1-y) , where x and y are any real numbers from 0 to 1. The insulating layer 42 is silicon dioxide (SiO ₂ ) or silicon nitride (Si ₃ N ₄ ), and has a thickness of about 0.1 μm to 0.2 μm.

In addition to the channel function of the TFT, the channel layer 43 also has the function of a second light absorption layer, and the light absorption wavelength band of the channel layer 43 is different from that of the gate p-type semiconductor layer 412. It is supplemented that the "first" and "second" of the first light absorbing layer and the second light absorbing layer are not used to limit any order, but to distinguish the channel layer 43 from the gate p-type semiconductor The light absorption wavelength band of the layer 412 is different. The channel layer 43 is made of n-type semiconductor, specifically n-type zinc oxide (n-ZnO) or n-type indium tin oxide (n-ITO). The drain metal electrode 44 and the source metal electrode 45 are spaced apart from each other and are located on the surface of the channel layer 43. The drain metal electrode 44 and the source metal electrode 45 may be aluminum (Al) or aluminum alloy. The main single-layer or multi-layer film structure.

The foregoing description of the layer stack structure and materials of each photosensitive thin film transistor 4 is only an embodiment of the present invention, and should not be used to limit the scope of the present invention. In addition, a protective layer or an anti-static interference layer is disposed on the light-receiving surface of the single sensing pixel 3 (that is, above the channel layer 43 and above the source metal electrode 45 or the drain metal electrode 44), or, on the gate metal A p-type heavily doped CuIn _x Ga _(1-x) Se _y S _(1-y) (referred to as p ⁺ -CIS system) film layer is arranged between the electrode 411 and the CIS gate p-type semiconductor layer 412, or The additional resistors, capacitors, etc., which are configured in consideration of the timing of external digital signal processing, are still within the scope of the present invention.

Referring to FIGS. 1, 3 and 4, when the present invention is used, electromagnetic wave signals including ultraviolet light, visible light and near-infrared light are incident into the thin film array unit 2 from the top to the bottom through the light receiving surface 22 of the thin film array unit 2. The gate driving line 301 operates the photosensitive thin film transistor 4 in an on mode at a fixed frame rate. When the photosensitive thin film transistor 4 detects the electromagnetic wave signal of an object to be measured, the photosensitive thin film transistor 4 can be turned on to transmit the photocurrent data to, for example, a digital image processing circuit (not shown) for analysis The two-dimensional overall picture of the object to be measured is reconstructed. Among them, the CIS-based gate p-type semiconductor layer 412 serves as the first light absorbing layer, which mainly generates photocurrent for signals in the visible light and near-infrared light bands, and the n-type ZnO or n-type ITO channel layer 43 serves as the second light absorbing layer. The photocurrent is generated for the signal in the ultraviolet light band to realize the image sensing function including ultraviolet light, visible light and near-infrared light.

The electromagnetic wave detection device capable of detecting ultraviolet light, visible light waveband and near-infrared light waveband of the present invention can be applied to the lens of smart phone, digital camera, computer network camera module, IoT sensor and other products. In addition, the sensing of ultraviolet light and near-infrared light can be applied to organic molecule detection and biomedical detection technology.

In summary, with the innovative structure of the photosensitive thin film transistor 4, it has the functions of scanning driving, data transmission and detecting electromagnetic wave signals. Therefore, the photosensitive thin film transistor 4 is used to replace the previous crystalline silicon PN light diode. Body, or amorphous silicon PIN photodiode with CMOS circuit, or to replace the conventional amorphous silicon PIN sensing thin film array driven by TFT scanning. The advantage of the present invention is that because the CIS system (including copper indium selenium (CIS) and The copper indium gallium selenide (CIGS) film is a direct energy gap material. The thickness of the CIS gate p-type semiconductor layer 412 is much smaller than that of the crystalline silicon PN photodiode, so that the gate p-type semiconductor layer 412 can be used in the near infrared light band. Have better quantum efficiency. In addition, under the same area, the spectral response of the CIS gate p-type semiconductor layer 412 in near-infrared light is better than that of the amorphous silicon PIN film, and its photoelectric conversion efficiency is at least that of a general amorphous silicon PIN photodiode. More than 2 times. The current world record of photoelectric conversion efficiency of CIS film has reached 22.9%. Therefore, the present invention adopts the CIS-based gate p-type semiconductor layer 412, and the n-ZnO or n-ITO channel layer 43 has a good spectral response to ultraviolet light, which can improve the near-infrared light and ultraviolet light spectral response of the thin film array unit 2 And photoelectric conversion efficiency.

In addition, compared to the conventional amorphous silicon PIN sensing thin film array driven by TFT scanning, which requires more than 12 masks in the production process, the photosensitive thin film transistor 4 of the present invention is itself a photosensitive element, and no additional The photosensitive diode, therefore, greatly simplifies the production process technology, can reduce the number of mask manufacturing processes, makes the thin film array unit 2 easy to manufacture, and can realize large-area full-view electromagnetic wave detection.

Referring to FIG. 5, a second embodiment of the electromagnetic wave detection device of the present invention has substantially the same structure as the first embodiment, except that the second embodiment further includes a light-receiving surface 22 on the thin film array unit 2. The wavelength modulation unit 7 is used to convert the wavelength of the incident electromagnetic wave so that the converted electromagnetic wave wavelength becomes the detectable wavelength range of the thin film array unit 2. The electromagnetic wave signals including ultraviolet light, visible light and near-infrared light are incident from top to bottom, and enter the wavelength modulation unit 7 and the thin film array unit 2 in sequence.

The wavelength modulation unit 7 may be a wavelength conversion film layer that can convert the wavelength band of incident electromagnetic waves to another wavelength band, and the wavelength conversion film layer can convert near-infrared incident light with a wavelength of 1.1 μm to 2.5 μm into a wavelength less than 1.1 μm For example, LiYF ₄ :Er ³⁺ nano-crystalline material, or nano-carbon structure material designed and functionalized by Bandgap Engineering. Although this type of "Up-conversion" material that converts low-energy electromagnetic waves to high-energy electromagnetic waves, its wavelength conversion efficiency is not high, but because the present invention uses a p-type semiconductor layer 412 containing a CIS-based gate electrode (Figure 4) ) The photoelectric conversion efficiency of the CIS-based gate p-type semiconductor layer 412 (FIG. 4) is at least twice that of the known amorphous silicon PIN photodiode. Therefore, the present invention can still be used in conjunction The up-conversion material is used as the wavelength modulation unit 7 to detect electromagnetic wave signals with high signal-to-noise ratio (Signal-to-Noise Ratio) after wavelength conversion.

The wavelength modulation unit 7 can also use a "down-conversion" material that converts high-energy electromagnetic waves to low-energy electromagnetic waves, so as to convert high-energy electromagnetic wave signals into a band with higher CIS spectral response quantum efficiency. Taking the application of X-ray flat panel detection device as an example, the preferred embodiment of the wavelength modulation unit 7 is a cesium iodide (CsI) film, which is matched with the photoelectricity of the CIS-based gate p-type semiconductor layer 412 (FIG. 4) of the present invention The conversion efficiency is at least twice the photoelectric conversion efficiency of the conventional amorphous silicon PIN photodiode. Therefore, the second embodiment can greatly reduce the amount of energy used in the detection process in applications that require wavelength conversion such as X-ray detection. X-ray radiation intensity.

3, 4, and 5, another implementation aspect of the wavelength modulation unit 7 includes a plurality of filters arranged in an array, and the filters are respectively arranged in the sensing pixels 3 according to the needs of the detection function. On the light-receiving surface. For example, the emission wavelength range of known fluorescent targets for biomedical testing can be roughly divided into the first detection band with wavelengths from 650nm to 950nm, and the second detection band with wavelengths from 1000nm to 1350nm. When the function of the electromagnetic wave detection device of the present invention must be able to detect the detection wavebands of the two fluorescent cursor targets at the same time, the wavelength modulation units 7 of the thin film array unit 2 are designed to be bandpasses for these two wavebands. Bandpass Filter, the bandpass filters of these two bands can be interspersed and arranged on the M×N sensing pixels 3 of the present invention. The above-mentioned wavelength modulation unit 7 in the form of a band-pass filter modulates incident electromagnetic waves with a wavelength less than 2.5 μm.

In addition, since the photoelectric conversion efficiency of the CIS-based gate p-type semiconductor layer 412 is at least twice that of the conventional amorphous silicon PIN photodiode, the CIS-based gate can be combined with the present invention. The flat panel detection device of the p-type semiconductor layer 412 maintains high sensitivity, so the wavelength modulation unit 7 of the present invention may not be limited to a single one, but may also have several. For example, in the variation shown in FIG. 6, the light-receiving surface 22 of the thin film array unit 2 is provided with two wavelength modulation units 7 stacked one above the other, the lower wavelength modulation unit 7 includes a filter, and the upper The wavelength modulation unit 7 includes a wavelength conversion film layer. During implementation, the order of the filter and the wavelength conversion film can also be changed. Or, the two wavelength modulation units 7 are both filters, but the filtered wavelength bands are different. Or, the two wavelength modulation units 7 are both wavelength conversion films, and the wavelength bands obtained after conversion are different.

Referring to FIG. 7, a third embodiment of the electromagnetic wave detection device of the present invention has substantially the same structure as the first embodiment, except that the third embodiment further includes a light-receiving surface 22 located on the thin film array unit 2.的phase modulation unit 8. The electromagnetic wave signals including ultraviolet light, visible light and near-infrared light are incident from top to bottom, and enter the phase modulation unit 8 and the thin film array unit 2 in sequence.

The phase modulation unit 8 refers to the use of light-transmissive or semi-transmissive diaphragm materials to produce spatially variable microstructures to modulate the spatial light after electromagnetic waves are incident on each photosensitive thin film transistor 4 (Figure 4) The path difference achieves the function of phase modulation. The phase modulation unit 8 can be a microstructure film with a periodic change in refractive index, including but not limited to: microlens, phase grating, or coded aperture. Next, the phase modulation units 8 of these three different implementations are respectively described.

Wherein, when the phase modulation unit 8 adopts microlenses, it mainly achieves the function of condensing and imaging. Therefore, in terms of the entire electromagnetic wave detection device, the phase modulation unit 8 includes several microlenses arranged in an array. The spatial period of the array is exactly the same as the spatial period of the array of sensing pixels 3 (Figure 2), achieving one-to-one condensing imaging.

When the phase modulation unit 8 adopts a phase grating, it can detect three-dimensional information of an object to be detected. For example, the electromagnetic wave detection device of the present invention can be used to detect near-infrared light waveband (>650nm) biomedical detection, and the corresponding phase grating belongs to the precision of micron line width processing, and it is easy to use the current semiconductor processing technology or the conventional Know the optical microstructure processing technology (for example: laser engraving, or micro-nano stamping technology) to achieve. Application of phase grating is to reconstruct (decode) the three-dimensional image of the object under test by using an algorithm that matches the design rule of the phase grating to reconstruct (decode) the three-dimensional information of the object under test that has been modulated (encoded) by the phase grating. .

When the phase modulation unit 8 adopts an encoded aperture (ie, an encoded pinhole array), it can be used to change the optical path difference of the electromagnetic wave to improve the spatial resolution of the entire electromagnetic wave detection device. Similarly, the corresponding coded aperture size is the same as the accuracy of micron line width processing, and it is easy to use current semiconductor processing technology or conventional optical microstructure processing technology (for example: laser engraving, or micro-nano stamping technology) )to fulfill.

The phase modulation unit 8 of the present invention may not be limited to a single one, and there may be several. For example, in the variation shown in FIG. 8, the light-receiving surface 22 of the thin film array unit 2 is provided with two phase modulation units 8 stacked one above the other.

Referring to FIG. 9, a fourth embodiment of the electromagnetic wave detection device of the present invention has substantially the same structure as the second embodiment (FIG. 5), except that: the fourth embodiment also includes the wavelength modulation unit 7 The phase modulation unit 8 of the fourth embodiment is the same as the phase modulation unit 8 of the third embodiment (FIG. 7). The electromagnetic wave signals including ultraviolet light, visible light and near-infrared light are incident from top to bottom, and enter the phase modulation unit 8, the wavelength modulation unit 7 and the thin film array unit 2 in sequence. By arranging the wavelength modulation unit 7 and the phase modulation unit 8 at the same time, the functions and advantages of the two can be combined, and the wavelength of the incident electromagnetic wave can be converted to the wavelength band that the invention can detect, and it can be applied to 3D image detection. . In implementation, the upper and lower positions of the wavelength modulation unit 7 and the phase modulation unit 8 can also be reversed.

The substrate 1, the thin film array unit 2, the wavelength modulation unit 7, and the phase modulation unit 8 described in the above embodiments of the present invention may adopt vacuum or non-vacuum manufacturing processes and processing methods. The wavelength modulation unit 7 and the phase modulation unit 8 can also be different films and use optical adhesive (OCA) to glue the film array unit 2. There are a variety of structures, materials, and manufacturing methods during implementation, all of which can form the laminated structure required by the present invention, so there is no need to limit the implementation.

In summary, the present invention has the following advantages: (1) The structural innovation of the photosensitive thin film transistor 4 includes a gate p-type semiconductor layer 412 and an n-type channel layer 43, which serve as the first light absorption layer and the second light absorption layer, respectively. The light absorption layer can enhance the spectral response of near-infrared light and ultraviolet light. (2) Use the driving and scanning functions of the photosensitive thin film transistor 4 array to detect electromagnetic wave signals to realize large-area full-view electromagnetic wave detection, and the structure is simple and the production process is simplified. (3) Improve the photoelectric conversion efficiency of the thin film array unit 2, so that the phase modulation unit 8 (Figure 7), or wavelength modulation units such as filters, wavelength conversion films, etc., are additionally arranged on the light receiving surface 22 of the thin film array unit 2 7 (Figure 5, Figure 6), the sensitivity required by the detection function can still be maintained. The configuration of the phase modulation unit 8 can realize three-dimensional information or high-resolution image reconstruction, and the configuration of the wavelength modulation unit 7 can realize the wavelength multiplexing function of the electromagnetic wave detection device. (4) The substrate 1, the thin film array unit 2, the wavelength modulation unit 7 and the phase modulation unit 8 are all films or sheets, so that the device of the present invention is a flat plate as a whole. This is a flat plate electromagnetic wave detection device with Thin and light advantages. The invention can realize a high-photoelectric conversion efficiency, low-cost, large-area flat-plate electromagnetic wave detection device, and can be applied to an image detection device with an electromagnetic wave wavelength range of less than 2.5 μm (including ultraviolet light, visible light, and near-infrared light band). When the phase modulation unit 8 is provided in combination, the present invention can further refer to a three-dimensional image detection device, which has a good effect on three-dimensional image reconstruction and improvement of spatial resolution.

However, the above are only examples of the present invention. When the scope of implementation of the present invention cannot be limited by this, all simple equivalent changes and modifications made in accordance with the scope of the patent application of the present invention and the content of the patent specification still belong to This invention patent covers the scope.

1: substrate 2: Thin film array unit 21: Backlight 22: Light-receiving surface 3: Sensing pixels 301: Gate drive line 302: Data scan line 4: Photosensitive thin film transistor 41: gate electrode 411: gate metal electrode 412: gate p-type semiconductor layer 42: insulating layer 43: channel layer 44: Drain metal electrode 45: source metal electrode 7: Wavelength modulation unit 8: Phase modulation unit

Other features and effects of the present invention will be clearly presented in the embodiments with reference to the drawings, in which: 1 is a schematic side view of a first embodiment of the electromagnetic wave detection device of the present invention; 2 is a schematic top view of the first embodiment, illustrating that a thin film array unit of the first embodiment includes a plurality of sensing pixels arranged in an array; FIG. 3 is a schematic diagram of an equivalent circuit of any one of the sensing pixels; 4 is a schematic diagram illustrating the laminated structure of a photosensitive thin film transistor of the sensing pixel; 5 is a schematic side view of a second embodiment of the electromagnetic wave detection device of the present invention; 6 is a schematic side view of a modified aspect of the second embodiment; 7 is a schematic side view of a third embodiment of the electromagnetic wave detection device of the present invention; FIG. 8 is a schematic side view of a modified aspect of the third embodiment; FIG. 9 is a schematic side view of a fourth embodiment of the electromagnetic wave detection device of the present invention.

1: substrate

3: Sensing pixels

4: Photosensitive thin film transistor

41: gate electrode

411: gate metal electrode

412: gate p-type semiconductor layer

42: insulating layer

43: channel layer

44: Drain metal electrode

45: source metal electrode

Claims (7)

A photosensitive thin film transistor is formed on a substrate and includes: a gate electrode, which sequentially includes a gate metal electrode and a gate p-type semiconductor layer from being adjacent to and away from the substrate. The gate p The type semiconductor layer is CuIn _x Ga _(1-x) Se _y S _(1-y) , where x is any real number from 0 to 1, and y is any real number from 0 to 1, and the gate p-type semiconductor layer has both The function of the first light absorbing layer; an insulating layer located above the gate p-type semiconductor layer, the insulating layer being SiO ₂ or Si ₃ N ₄ ; a channel layer located above the insulating layer, the channel layer being n-type ZnO or n-type ITO, and also has the function of the second light absorption layer, and the light absorption band of the channel layer is different from that of the gate p-type semiconductor layer; a drain metal electrode is located on the channel layer And a source metal electrode located on the channel layer and spaced from the drain metal electrode. An electromagnetic wave detection device, including: A substrate; and A thin film array unit is formed on the substrate and includes a backlight surface facing the substrate, a light receiving surface opposite to the backlight surface, and M×N sensing pixels, where M and N are both positive integers Each sensing pixel includes a photosensitive thin film transistor as described in claim 1, and the photosensitive thin film transistor is used for scanning drive and data transmission, and for detecting electromagnetic wave signals. The electromagnetic wave detection device according to claim 2, further comprising a wavelength modulation unit arranged on the light-receiving surface of the thin film array unit and used for converting the wavelength of incident electromagnetic waves. The electromagnetic wave detection device according to claim 3, wherein the wavelength modulation unit is a wavelength conversion film or a filter. The electromagnetic wave detection device according to claim 3, further comprising a phase modulation unit which is provided on the wavelength modulation unit and is used to adjust the phase of the incident electromagnetic wave. The electromagnetic wave detection device according to claim 2, further comprising a phase modulation unit arranged on the light-receiving surface of the thin film array unit and used for adjusting the phase of incident electromagnetic waves. The electromagnetic wave detection device according to claim 5 or 6, wherein the phase modulation unit includes a microlens, a phase grating, or an encoded aperture.

Images