An ultra-narrowband photodetector array based on photonic optoelectronic chip integration
By integrating an ultra-narrowband photodetector array on a photonic optoelectronic chip, and utilizing optical gratings and perovskite photodetector structures, the limitations of traditional narrowband photodetectors in multi-wavelength detection and on-chip integration have been overcome, achieving high-resolution, low-cost narrowband photodetection.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- HARBIN INST OF TECH SHENZHEN GRADUATE SCHOOL
- Filing Date
- 2022-11-23
- Publication Date
- 2026-06-02
AI Technical Summary
Traditional narrowband photodetectors suffer from problems such as wide response bandwidth, color artifacts, and high cost in multi-wavelength detection capabilities and on-chip integrated systems. Existing filterless narrowband photodetectors based on emerging materials have limitations in wavelength tuning and integration.
An ultra-narrowband photodetector array integrated on a photonic optoelectronic chip is used. By generating an optical grating at the edge of the perovskite photodetector and forming the optical grating using an electron beam exposure resist, and combining it with a perovskite filter layer, a hole transport layer, an anode metal layer and an electron transport layer, narrowband detection is achieved.
It achieves ultra-narrowband photoelectric detection with a half-width at half-maximum of approximately 7.2 nm, featuring high resolution and multi-wavelength detection capabilities. The process is simple and low-cost, making it suitable for precision detection and integrated optical applications.
Smart Images
Figure CN115835662B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of photodetectors, and in particular to an ultra-narrowband photodetector array based on on-chip photonic optoelectronic integration. Background Technology
[0002] Traditional narrowband photodetectors in semiconductors are typically implemented by adding an input optical filter to a broadband device. While this method achieves narrowband detection, it inevitably increases manufacturing costs and system size. Recently, filterless narrowband photodetectors based on emerging materials (such as organic semiconductors and metal halide perovskites) have been developed, relying on mechanisms such as internal filtering, narrowband absorption, and microcavity resonance.
[0003] While filterless narrowband photodetectors based on emerging materials (such as organic semiconductors and metal halide perovskites) have been developed using mechanisms such as internal filtering, narrowband absorption, and microcavity resonance, the resulting devices respond only within a specific wavelength range and have fixed material composition / thickness or device configurations. This hinders their application in on-chip integrated systems with multi-wavelength detection capabilities. Furthermore, the relatively wide response bandwidth in these devices leads to color artifacts, further limiting their application in advanced systems.
[0004] Given the increasingly stringent requirements for the response bandwidth and wavelength tunability of photodetectors in integrated photonic and optoelectronic systems, there is an urgent need to develop a new generation of filterless narrowband photodetectors on-chip, with performance exceeding that of existing technologies. Summary of the Invention
[0005] This invention provides an ultra-narrowband photodetector array based on on-chip photonic optoelectronic integration, aiming to provide an optoelectronic integration mechanism suitable for ultra-narrowband photodetection, applicable to various optoelectronic materials.
[0006] This invention provides an ultra-narrowband photodetector array based on on-chip photonic optoelectronics, comprising a perovskite photodetector, a substrate, and an electron beam photoresist. The perovskite photodetector covers a portion of the substrate, and an electron beam photoresist layer is deposited on the entire substrate, covering both the perovskite photodetector and the exposed substrate area. An optical grating is generated by exposing the exposed substrate area near the edge of the perovskite photodetector with an electron beam.
[0007] As a further improvement of the present invention, the perovskite photodetector includes a perovskite filter layer, a hole transport layer, and an anode metal layer. The perovskite filter layer is disposed on a substrate, the hole transport layer is disposed on the perovskite filter layer, and the anode metal layer is disposed on the hole transport layer.
[0008] As a further improvement of the present invention, the substrate includes an electron transport layer and a cathode layer, the electron transport layer being disposed on the cathode layer, and the perovskite photodetector being disposed on the electron transport layer.
[0009] As a further improvement of the present invention, the electron transport layer is a tin dioxide coating.
[0010] As a further improvement of the present invention, the cathode layer is a tin-doped indium oxide glass substrate.
[0011] As a further improvement of the present invention, the thickness of the electron transport layer is in the range of 20-100 nm, the thickness of the cathode layer is in the range of 20-100 nm, and the thickness of the electron beam exposure resist is in the range of 120-600 nm.
[0012] As a further improvement of the present invention, the electron beam exposure adhesive is ZEP520A.
[0013] As a further improvement of the present invention, during electron beam exposure, the light resonance of different wavelengths of the electron beam is adjusted to form optical gratings with different grating periods and grating strip widths.
[0014] The beneficial effects of this invention are:
[0015] (1) Small size: The size of the optical grating that achieves the filtering effect is in the tens of micrometers, which is more conducive to the application in integrated optics.
[0016] (2) Half-width of the detection wavelength: The half-width of the detection wavelength is about 7.2 nm, which is much lower than the width currently reported. A narrow half-width means higher resolution and is more conducive to applications in precision detection.
[0017] (3) Simple process, low power consumption and high efficiency: Narrowband detectors are simple to manufacture and are cheaper than other detectors, and have better development prospects.
[0018] (4) Multiple detectable bands and easy integration: The fabricated narrowband detector can realize narrowband detection of all visible light bands and can integrate the full-band detector on the chip, providing a new direction for the integration field.
[0019] (5) Novel narrowband detection mechanism: The fabricated narrowband detector adopts a novel narrowband detection mechanism, which is realized through the optical diffraction filtering principle and waveguide principle. The principle is simple and the fabrication is easy.
[0020] (6) Excellent device performance: Compared with traditional narrowband photodetectors, it has better performance, mainly reflected in power conversion efficiency, response speed and external quantum efficiency. Traditional narrowband implementation methods rely on sacrificing the performance of the device itself, while the new narrowband photodetector improves the original device performance, which is more advantageous than traditional implementation methods. Attached Figure Description
[0021] Figure 1 This is a schematic diagram of the structure of the ultra-narrowband photodetector array in this invention;
[0022] Figure 2 This is a SEM image of the ultra-narrowband photodetector array in this invention;
[0023] Figure 3 This is a schematic diagram of the narrowband principle in this invention;
[0024] Figure 4 This is a top-view SEM image of the optical grating with resonant wavelength in this invention;
[0025] Figure 5 This is the transmission spectrum obtained through simulation and experimentation in this invention;
[0026] Figure 6 This is a schematic diagram of the transmission of resonant light in this invention;
[0027] Figure 7 This is a diagram showing the experimental results of the narrowband detection capability in this invention;
[0028] Figure 8 This is an optical image of the three-wavelength integrated device in this invention. Detailed Implementation
[0029] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments.
[0030] This invention proposes an optoelectronic integration mechanism suitable for ultra-narrowband photodetectors, applicable to various optoelectronic materials. Taking an ultra-narrowband perovskite photodetector as an example, its response bandwidth is as narrow as 7.2 nm, representing the first sub-10 nm narrowband response in a perovskite structure. Simultaneously, this mechanism provides a simplified method for on-chip integration of multi-wavelength narrowband photodetectors. The post-fabrication process of the perovskite photodetector has a negligible impact on device performance, offering advanced application prospects for perovskite optoelectronic chip integration.
[0031] like Figure 1As shown, the present invention discloses an ultra-narrowband photodetector array based on on-chip photonic optoelectronics, comprising a perovskite photodetector 1, a substrate 2, and an electron beam photoresist 3. The perovskite photodetector 1 covers a portion of the substrate 2, and an electron beam photoresist 3 is deposited on the entire substrate 2. The electron beam photoresist 3 covers the perovskite photodetector and the exposed area of the substrate 2. An optical grating 4 is generated by exposure of the exposed area of the substrate 2 near the edge of the perovskite photodetector 1 with an electron beam.
[0032] During electron beam exposure, the resonance of different wavelengths of the electron beam is adjusted to form optical gratings with different grating periods and grating strip widths. While controlling the electron beam wavelength, the half-width at half-maximum (WHM) of the electron beam must be kept within the narrowest possible range, and the coupling efficiency of the formed optical gratings must be maximized.
[0033] The perovskite photodetector 1 includes a perovskite filter layer 11, a hole transport layer 12, and an anode metal layer 13. The perovskite filter layer 11 is disposed on a substrate 2, the hole transport layer 12 is disposed on the perovskite filter layer 11, and the anode metal layer 13 is disposed on the hole transport layer 12. The hole transport layer 12 is preferably made of HTL (Hole Transport Layer) material and is used to transport holes generated by the perovskite layer. The anode metal layer 13 is preferably gold, but other metals can also be used. The energy level of the selected metal is matched with the energy levels of the perovskite filter layer, the hole transport layer, and the substrate.
[0034] Substrate 2 includes an electron transport layer and a cathode layer. The electron transport layer is disposed on the cathode layer, and the perovskite photodetector 1 is disposed on the electron transport layer. The electron transport layer is a tin dioxide coating, and the cathode layer is a tin-doped indium oxide glass substrate.
[0035] This invention presents a photoelectronic integration mechanism for constructing narrowband photodetectors, demonstrating ultra-narrowband response, on-chip integration capability, and wide wavelength tunability. An in-plane optical grating 4 is designed using conjugate modes (BICs) of bound states in a continuous medium, which can generate resonant light with an ultra-narrow linewidth at the desired wavelength. Perovskite, due to its excellent photoelectric properties, is used to fabricate high-performance photodetectors. After rational photonic design and fabrication, the grating is integrated with a high-performance perovskite photodetector. The resonant light is successfully extracted and coupled into a combined waveguide, thus propagating to the perovskite absorber to obtain ultra-narrowband signal detection. This unique design makes the performance variation of the perovskite detector negligible and enables narrowband photodetectors with response bandwidths below 7.2 nm, outperforming state-of-the-art perovskite-based photodetectors. Furthermore, the proposed mechanism provides a unique opportunity to fabricate ultra-narrowband perovskite photodetectors with multi-wavelength responses using simple fabrication processes and device configurations, which will facilitate their on-chip integration for advanced applications of photonic crystals.
[0036] A schematic diagram of an ultra-narrowband perovskite photodetector is shown below. Figure 1 As shown, a grating composed of electron beam spectroscopy resist 3 (ZEP520A) was fabricated onto an indium tin oxide (ITO) glass substrate coated with tin dioxide (SnO2) by electron beam spectroscopy (EBL). In principle, periodic nanostructures can support BIC modes with extremely high Q values, which have been successfully introduced into photonics to significantly improve the performance of lasers and metasurfaces. Due to their relatively low Q values, conjugate modes of BIC have previously been neglected. From a reciprocity perspective, conjugate BIC corresponds to enhanced coupling efficiency of incident light, which is highly advantageous for ultra-narrowband photodetectors. ITO, SnO2, and ZEP520A are used collectively as a combined waveguide, and as electrodes, electron transport layers, and encapsulation layers for the photodetector, respectively. When light is projected onto the grating, resonant light couples to the waveguide mode and is transmitted to the adjacent photodetector. However, non-resonant light is directly transmitted to free space. Thus, an ultra-narrowband photodetector is formed.
[0037] In this study, a perovskite photodetector 1 was fabricated for the first time on an ITO substrate 2 coated with SnO2 by partially covering the substrate 2. A ZEP520A layer was then deposited over the entire substrate 2, covering both the perovskite photodetector and the exposed SnO2-coated ITO substrate 2. An optical grating 4 was then generated in the exposed area near the edge of the photodetector using an EBL patterning process. Scanning electron microscopy (SEM) images of this compact device are shown below. Figure 2 As shown, the magnified SEM image reveals the details of the grating. The overall device size is approximately 100 × 150 μm, making it ideal for ultra-small devices.
[0038] Systematic theoretical and experimental studies were conducted to reveal the functions of integrated photonics, such as... Figure 3 As shown in (a). Figure 3 (a) is a schematic diagram of the incident light onto a quasi-BIC grating. First, the refractive index (n) and extinction coefficient (k) of each layer constituting the system are characterized as input parameters for theoretical research. Here, the thicknesses of ITO, SnO2, and ZEP520A range from 20-100 nm, 20-100 nm, and 120-600 nm, respectively. The grating period and grating strip width can be adjusted for different wavelengths of light resonance. Through grating diffraction, resonant light with a specific wavelength can be coupled into the waveguide to form a standing wave. The light coupled into the waveguide propagates to both sides, propagating in a waveguide mode, such as... Figure 3 As shown in (b) Figure 3(b) shows the incident light coupling mode into the waveguide. Position 5 in the figure represents the light mode in the waveguide, and different gray levels represent different light energy intensities. Therefore, the transmission of resonant light will be suppressed, while non-resonant light of other wavelengths will be transmitted to free space through the grating.
[0039] Based on this ultra-narrowband photodetector array, the spacing and size of the gratings at different resonant wavelengths were systematically studied. By arranging the gratings, resonant wavelengths covering the visible light range can be achieved. After design, the following was obtained: Figure 4 SEM images of gratings at three representative resonant wavelengths of 454 nm, 540 nm, and 654 nm, shown in (a), 4(b), and 4(c).
[0040] like Figure 5 As shown, the transmission spectra of the three different wavelength bands of light were obtained by transmission optical path testing of the prepared sample, and the full width at half maximum (FWHM) of all transmission tilt angles was less than 10 nm, proving that the coupled resonance light is an ultra-narrow band.
[0041] Light coupled into the waveguide propagates through the ITO+SnO2+Zep520A waveguide and eventually reaches the photodetector, generating the photoelectric effect. The propagation direction and process of the resonant light were designed and calculated using optical simulation software. Figure 6 As shown. Figure 6 (a) shows that the resonant light will propagate longitudinally in the plane perpendicular to the grating strips, with the arrow indicating the direction of propagation; Figure 6 (b) Resonant light absorption in a perovskite photodetector. Due to the high refractive index of the perovskite structure, the resonant light propagating through the waveguide will be further transmitted into the perovskite structure layer to obtain a photoelectric signal.
[0042] Experimental measurements were conducted to demonstrate ultra-narrowband detection in an integrated device by projecting light onto a grating. Figure 7(a) shows the wavelength-dependent normalized photocurrent of an ultra-narrowband perovskite photodetector with different grating parameters. Due to the excellent light confinement capability of the conjugate BIC grating, the ultra-narrowband photoresponse of the perovskite photodetector can be significantly reduced to 7.2 nm. This value can be further reduced to match the full width at half maximum (FWHM) of the transmission tilt angle, without being limited by the spectral resolution of the bandpass filter used. Furthermore, the photodetector also exhibits high wavelength selectivity in the visible spectrum. The photocurrent from wavelengths outside the resonant wavelength range is extremely low, averaging 1% compared to the resonant wavelength. This high light selectivity is attributed to the fact that non-resonant light is directly transmitted into free space, rather than being absorbed by the perovskite layer as in conventional perovskite narrowband photodetectors. As previously described, this system utilizes a single device and device fabrication process, providing the conditions for on-chip integration of multi-wavelength ultra-narrowband light detection. In this case, three optical gratings 4 with different resonant wavelengths are integrated into a single perovskite photodetector for demonstration. Figure 7 (b) shows the time-dependent photoelectric response of the three-wavelength integrated device under different illumination conditions. The device successfully responded to three different monochromatic incident lights and white light, demonstrating the ability to achieve multi-wavelength narrowband detection on a single device.
[0043] Figure 8 (a) is an optical image viewed from an oblique angle, showing the optical image of a three-wavelength integrated device, in which a beam of white light is projected onto three parallel-positioned optical gratings 4 with different resonant wavelengths. The three resonant beams corresponding to different wavelengths are clearly visible, illustrating the capability of multi-wavelength integration. Specifically, Figure 8 (a) is an optical image in a horizontal view that reveals resonant light emitted from the top layer at the edge of the device, indicating that the light can be confined in a waveguide located on the surface of substrate 2, rather than leaking into substrate 2.
[0044] The above description, in conjunction with specific preferred embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of the present invention, and all such modifications and substitutions should be considered within the scope of protection of the present invention.
Claims
1. A type of ultra-narrowband photodetector array integrated on a photonic optoelectronic chip, characterized in that, The device includes a perovskite photodetector, a substrate, and an electron beam photoresist. The perovskite photodetector covers a portion of the substrate, and an electron beam photoresist is deposited on the entire substrate. The electron beam photoresist covers both the perovskite photodetector and the exposed substrate area. An optical grating is generated by exposing the exposed substrate area near the edge of the perovskite photodetector with an electron beam. In-plane optical gratings are designed using the conjugate modes of bound states in a continuous medium to generate resonant light with an ultra-narrow linewidth of wavelength. Through diffraction of the optical grating, the resonant light with a specific wavelength is coupled into a waveguide to form a standing wave, which propagates in the mode of the waveguide.
2. The ultra-narrowband photodetector array based on on-chip photonic optoelectronic integration as described in claim 1, characterized in that, The perovskite photodetector includes a perovskite filter layer, a hole transport layer, and an anode metal layer. The perovskite filter layer is disposed on a substrate, the hole transport layer is disposed on the perovskite filter layer, and the anode metal layer is disposed on the hole transport layer.
3. The ultra-narrowband photodetector array based on on-chip photonic optoelectronic integration according to claim 1, characterized in that, The substrate includes an electron transport layer and a cathode layer, with the electron transport layer disposed on the cathode layer and the perovskite photodetector disposed on the electron transport layer.
4. The ultra-narrowband photodetector array based on on-chip photonic optoelectronics as described in claim 3, characterized in that, The electron transport layer is a tin dioxide coating.
5. The ultra-narrowband photodetector array based on on-chip photonics as described in claim 3, characterized in that, The cathode layer is a tin-doped indium oxide glass substrate.
6. The ultra-narrowband photodetector array based on on-chip photonic optoelectronic integration according to claim 3, characterized in that, The thickness of the electron transport layer ranges from 20 to 100 nm, the thickness of the cathode layer ranges from 20 to 100 nm, and the thickness of the electron beam photoresist ranges from 120 to 600 nm.
7. The ultra-narrowband photodetector array based on on-chip photonic optoelectronic integration according to claim 1, characterized in that, The electron beam exposure adhesive is ZEP520A.
8. The ultra-narrowband photodetector array based on on-chip photonic optoelectronic integration according to claim 1, characterized in that, During electron beam exposure, the resonance of light of different wavelengths of the electron beam is adjusted to form optical gratings with different grating periods and grating strip widths.