Tandem perovskite single crystal, high-resolution, flexible color image sensor

Abstract

A method of fabricating a perovskite single crystal image sensor is provided. The method includes providing a perovskite single crystal wafer; transferring the perovskite single crystal wafer onto a first flexible encapsulation layer to form a first structure; patterning the perovskite single crystal wafer to form an array of perovskite single crystal pixel elements using a lithography process; forming an array of electrode elements on a second flexible encapsulation layer to form a second structure; and stacking the first structure on the second structure such that each individual perovskite single crystal pixel element of the array of perovskite single crystal pixel elements is aligned to a respective pair of adjacent electrode elements of the array of electrode element to form a multilayer stacked structure.

Description

Tandem Perovskite Single Crystal, High-Resolution, Flexible Color Image SensorTECHNICAL FIELD

[0001] The present disclosure is generally related to semiconductor structures and electronics and, in particular embodiments, to image sensors for electronic devices.BACKGROUND

[0002] An image sensor is a device that captures light and converts the captured light into electrical signals to be used for forming an image or a video. A typical image sensor has an image sensing portion that includes a photosensitive area for collecting a charge in response to incident light. In an example, an image sensor may include light-sensitive pixels arranged in a uniform or regular pattern (e.g., in rows and columns). Each pixel may include a photosensor that produces an electrical signal corresponding to the intensity of light that falls on that pixel. Image sensors are widely used in various electronic devices, such as wearable devices, smartphones, medical imaging devices, digital cameras, automotive cameras, computer vision systems, etc.SUMMARY

[0003] The disclosed aspects / embodiments of the present disclosure provide systems and / or devices that include high-resolution, flexible color image sensors. More specifically, an image sensor includes an array of pixel elements (e.g., light-sensitive elements) fabricated from a high- quality perovskite single crystal wafer using lithography. A high-quality perovskite single crystal wafer may refer to a thin, flat piece of perovskite material, where the entire structure is a single, continuous crystal lattice without grain boundaries or other defects. Perovskite materials have a high photosensitivity, allowing for smaller sized and / or thinner pixel elements compared to silicon sensors. Lithography can provide precise patterning of elements with high-accuracy and precise controls of shapes, sizes, and / or spacings, thus allowing for uniform small-sized (e g., less than 20 micrometers (pm) by 20 pm), uniformly shaped, uniformly and closely spaced pixel elements in the array. Using perovskite single crystal material as light-sensitive elements and lithography for patterning may together provide high-resolution, high-sensitivity image sensors. Additionally, the array of perovskite single crystal pixel elements may be formed on a flexible encapsulation or substrate layer to provide a flexible image sensor suitable for various devices (e.g., wearableelectronics and / or non-flat image sensors). Further, multiple pixel element arrays, each made of a perovskite material tuned to absorb a different color light (e.g., red, blue, and green lights), may be stacked to form a tandem color image sensor, eliminating the need for a complex color fdter and / or additional micro-lens as in silicon sensors.

[0004] A first aspect of the embodiments of the present disclosure relates to an integrated circuit (IC) structure comprising an image sensor structure comprising one or more multilayer stacked structures, each of the multilayer stacked structures comprising a pixel array layer comprising a plurality of pixel elements, each comprising a perovskite single crystal material; an electrode layer adjacent to the pixel array layer, the electrode layer comprising a plurality of electrode elements, wherein each pair of adjacent ones of the plurality of electrode elements corresponds to a respective one of the plurality of pixel elements; a first flexible encapsulation layer, wherein the pixel array layer is between the first flexible encapsulation layer and the electrode layer; and a second flexible encapsulation layer, wherein the electrode layer is disposed between the second flexible encapsulation layer and the pixel array layer.

[0005] Optionally, in any of the preceding aspects, another implementation of the aspect provides that the plurality of pixel elements are formed from a perovskite single crystal wafer.

[0006] Optionally, in any of the preceding aspects, another implementation of the aspect provides that each of the first flexible encapsulation layer and the second flexible encapsulation layer comprises a flexible material comprising at least one of parylene-C, polymethyl methacrylate (PMMA), polyimide, polyester, silicon rubbers, urethane rubbers, epoxy resins, epoxy-based photoresist, or amorphous fluoropolymer.

[0007] Optionally, in any of the preceding aspects, another implementation of the aspect provides that a first pixel element and a second pixel element of the plurality of pixel elements in the pixel array layer have the same dimensions.

[0008] Optionally, in any of the preceding aspects, another implementation of the aspect provides that at least one of a width or a length of an individual pixel element of the plurality of pixel elements is less than 25 micrometers (pm).

[0009] Optionally, in any of the preceding aspects, another implementation of the aspect provides that a thickness of an individual pixel element of the plurality of pixel elements is between 0.1 micrometers (pm) and 2 pm.

[0010] Optionally, in any of the preceding aspects, another implementation of the aspect provides that the plurality of pixel elements are uniformly spaced from one another.

[0011] Optionally, in any of the preceding aspects, another implementation of the aspect provides that a pitch between adjacent pixel elements of the plurality of pixel elements is between 0.3 micrometers (pm) and 20 pm.

[0012] Optionally, in any of the preceding aspects, another implementation of the aspect provides that the perovskite single crystal material in an individual pixel element of the plurality of pixel elements comprises a chemical compound represented by a chemical formula: ABX3, A in the chemical formula comprises at least one of methylammonium ion (MA+), formamidinium cation (FA+), caesium ion (Cs+), calcium ion (Ca2+), or strontium ion (Sr2+), B in the chemical formula comprises at least one of lead (II) ion (Pb2+), tin (II) ion (Sn2+), titanium(IV) cation (Ti4+), niobium(V) ion (Nb5+), or manganese (IV) cation (Mn4+), and C in the chemical formula comprises at least one of oxygen (O2), fluoride ion (F ), chloride ion (Cl'), bromide ion (Br), or iodide ion (I').

[0013] Optionally, in any of the preceding aspects, another implementation of the aspect provides that the one or more multilayer stacked structures comprise a first multilayer stacked structure and a second multilayer stacked structure, and the second flexible encapsulation layer of the first multilayer stacked structure is adjacent to the first flexible encapsulation layer of the second multilayer stacked structure.

[0014] Optionally, in any of the preceding aspects, another implementation of the aspect provides that each of the plurality of pixel elements in the second multilayer stacked structure is aligned to a respective one of the plurality of pixel elements in the second multilayer stacked structure.

[0015] Optionally, in any of the preceding aspects, another implementation of the aspect provides that the perovskite single crystal material in the plurality of pixel elements in the first multilayer stacked structure is formed from a first perovskite chemical compound that absorbs an optical signal in a first wavelength range, and the perovskite single crystal material in the plurality of pixel elements in the second multilayer stacked structure is formed from a second perovskite chemical compound that absorbs an optical signal in a second wavelength range different than the first wavelength range.

[0016] Optionally, in any of the preceding aspects, another implementation of the aspect provides that a first electrode element and a second, adjacent electrode element of the plurality ofelectrode elements corresponding to an individual pixel element of the plurality of pixel elements comprise the same semiconductor material.

[0017] Optionally, in any of the preceding aspects, another implementation of the aspect provides that a first electrode element and a second, adjacent electrode element of the plurality of electrode elements corresponding to an individual pixel element of the plurality of pixel elements comprise different semiconductor materials.

[0018] Optionally, in any of the preceding aspects, another implementation of the aspect provides that an individual multilayer stacked structure of the one or more multilayer stacked structures further comprises a second electrode layer between the pixel array layer and the first flexible encapsulation layer, the second electrode layer comprising a plurality of second electrode elements, each corresponds to a respective one of the plurality of pixel elements.

[0019] Optionally, in any of the preceding aspects, another implementation of the aspect provides that the individual multilayer stacked structure further comprises a dielectric layer between the pixel array layer and the second electrode layer, the second electrode layer comprising a plurality of dielectric elements, each disposed between a respective one of the plurality of second electrode elements and a respective one of the plurality of pixel elements.

[0020] Optionally, in any of the preceding aspects, another implementation of the aspect provides that the plurality of electrode elements comprises a transparent electrode material comprising at least one of an indium tin oxide (ITO) or a transparent conductive oxide (TCO), conducting polymers, or carbon-based nanomaterials.

[0021] A second aspect of the embodiments of the present disclosure relates to an electronic device comprising a tandem color image sensor structure comprising a plurality of multilayer structures stacked along a first direction, wherein each of the plurality of multilayer structures comprises a first encapsulation layer, a pixel array layer, an electrode layer, a second encapsulation layer stacked in order along the first direction, the pixel array layer comprising an array of pixel elements, each comprising a perovskite single crystal material, and the electrode layer comprising an array of electrode elements, wherein each pair of adjacent electrode elements of the array of electrode elements is coupled to a respective pixel element of the array of pixel elements, and a lens to direct an optical signal to the tandem color image sensor structure.

[0022] Optionally, in any of the preceding aspects, another implementation of the aspect provides that the perovskite single crystal material in the array of pixel elements in a first multilayerstructure of the plurality of multilayer structures and the perovskite single crystal material in the array of pixel elements in a second multilayer structure of the plurality of multilayer structures absorb optical signals of different light colors.

[0023] Optionally, in any of the preceding aspects, another implementation of the aspect provides that the array of pixel elements in a first multilayer structure of the plurality of multilayer structures absorbs blue color light, the array of pixel elements in a second multilayer structure of the plurality of multilayer structures absorbs green color light, the array of pixel elements in a third multilayer structure of the plurality of multilayer structures absorbs red color light, and the second multilayer structure is between the first multilayer structure and the third multilayer structure.

[0024] Optionally, in any of the preceding aspects, another implementation of the aspect provides that each of the first encapsulation layer and the second encapsulation layer comprises a flexible material comprising at least one of parylene-C, polymethyl methacrylate (PMMA), polyimide, polyester, silicon rubbers, urethane rubbers, epoxy resins, epoxy-based photoresist, or amorphous fluoropolymer.

[0025] Optionally, in any of the preceding aspects, another implementation of the aspect provides that each individual pixel element of the array of pixel elements in a first multilayer structure of the plurality of multilayer structures is aligned to a respective individual pixel element of the array of pixel elements in a second multilayer structure of the plurality of multilayer structures.

[0026] Optionally, in any of the preceding aspects, another implementation of the aspect provides that at least a first and a second pixel elements in the array of perovskite single crystal pixel elements have the same dimensions.

[0027] Optionally, in any of the preceding aspects, another implementation of the aspect provides that the pixel elements in the array of pixel elements in an individual multilayer structure of the plurality of multilayer structures are uniformly spaced from one another.

[0028] Optionally, in any of the preceding aspects, another implementation of the aspect provides that a first electrode element and a second, adjacent electrode element of the array of electrode elements coupled to an individual pixel element of the array of pixel elements comprise the same semiconductor material.

[0029] Optionally, in any of the preceding aspects, another implementation of the aspect provides that a first electrode element and a second, adjacent electrode element of the array ofelectrode elements coupled to an individual pixel element of the array of pixel elements comprise different semiconductor materials.

[0030] Optionally, in any of the preceding aspects, another implementation of the aspect provides that an individual multilayer structure of the plurality of multilayer structures further comprises a second electrode layer between the pixel array layer and the first encapsulation layer, the second electrode layer comprising a plurality of second electrode elements, each coupled to a respective pixel element of the array of pixel elements.

[0031] Optionally, in any of the preceding aspects, another implementation of the aspect provides that the individual multilayer structure further comprises a dielectric layer between the pixel array layer and the second electrode layer, the dielectric layer comprising a plurality of dielectric elements, each disposed between a respective one of the plurality of second electrode elements and a respective pixel element of the array of pixel elements.

[0032] A third aspect of the embodiments of the present disclosure relates to a method of fabricating a perovskite single crystal image sensor. The method comprises providing a perovskite single crystal wafer; transferring the perovskite single crystal wafer onto a first flexible encapsulation layer to form a first structure; patterning the perovskite single crystal wafer to form an array of perovskite single crystal pixel elements using a lithography process; forming an array of electrode elements on a second flexible encapsulation layer to form a second structure; and stacking the first structure on the second structure such that each individual perovskite single crystal pixel element of the array of perovskite single crystal pixel elements is aligned to a respective pair of adjacent electrode elements of the array of electrode element to form a multilayer stacked structure.

[0033] Optionally, in any of the preceding aspects, another implementation of the aspect provides that each of the first and second flexible encapsulation layers comprises a flexible material comprising at least one of parylene-C, polymethyl methacrylate (PMMA), polyimide, polyester, silicon rubbers, urethane rubbers, epoxy resins, epoxy-based photoresist, or amorphous fluoropolymer.

[0034] Optionally, in any of the preceding aspects, another implementation of the aspect provides that the stacking the first structure on the second structure comprises orienting the first structure such that the array of perovskite single crystal pixel elements faces towards the array of electrode elements.

[0035] Optionally, in any of the preceding aspects, another implementation of the aspect provides that the method further comprises forming the first flexible encapsulation layer on a first substrate layer before transferring the perovskite single crystal wafer onto the first flexible encapsulation layer; forming the second flexible encapsulation layer on a second substrate layer before transferring the array of electrode elements onto the second flexible encapsulation layer; and. removing the first and second substrate layers from the multilayer stacked structure.

[0036] Optionally, in any of the preceding aspects, another implementation of the aspect provides that at least one of the forming the first flexible encapsulation layer or the forming the second flexible encapsulation layer is based on a film deposition technique including at least one of chemical vaporization deposition (CVD) or physical vapor deposition (PVD).

[0037] Optionally, in any of the preceding aspects, another implementation of the aspect provides that the method further includes providing a second perovskite single crystal wafer; transferring the second perovskite single crystal wafer onto a third flexible encapsulation layer to form a third structure; patterning the second perovskite single crystal wafer to form a second array of perovskite single crystal pixel elements using a lithography process; forming a second array of electrode elements on a fourth flexible encapsulation layer to form a fourth structure; stacking the third structure on the fourth structure such that each individual perovskite single crystal pixel element of the second array of perovskite single crystal pixel elements is aligned to a respective pair of adjacent electrode elements of the second array of electrode elements to form a second multilayer stacked structure; and stacking the multilayer stacked structure on the second multilayer stacked structure such that the fourth flexible encapsulation layer of the second multilayer stacked structure is adjacent to the first flexible encapsulation layer of the multilayer stacked structure.

[0038] Optionally, in any of the preceding aspects, another implementation of the aspect provides that the providing the perovskite single crystal wafer is based on a selection of a first perovskite chemical compound to absorb an optical signal in a first wavelength range, and the providing the second perovskite single crystal wafer is based on a selection of a second perovskite chemical compound to absorb an optical signal in a second wavelength range different than the first wavelength range.

[0039] Optionally, in any of the preceding aspects, another implementation of the aspect provides that the method further includes forming an electrode layer on the first flexible encapsulation layer before transferring the perovskite single crystal wafer, wherein the perovskitesingle crystal wafer is transferred onto the electrode layer; and patterning the electrode layer to form a second array of electrode elements, wherein the electrode layer and the perovskite single crystal wafer are patterned using the same lithography process such that each electrode element in the second array of electrode elements is aligned to a respective perovskite single crystal pixel element of the array of perovskite single crystal pixel elements.

[0040] Optionally, in any of the preceding aspects, another implementation of the aspect provides that the method further includes forming an electrode layer on the first flexible encapsulation layer; forming a dielectric layer on the electrode layer before transferring the perovskite single crystal wafer, wherein the perovskite single crystal wafer is transferred onto the dielectric layer; and patterning the electrode layer and the dielectric layer to respectively form a second array of electrode elements and an array of dielectric elements, wherein the electrode layer, the dielectric layer, and the perovskite single crystal wafer are patterned using the same lithography process such that each electrode element in the second array of electrode elements is aligned to a respective dielectric element of the array of dielectric elements and a respective perovskite single crystal pixel element of the array of perovskite single crystal pixel elements.

[0041] For the purpose of clarity, any one of the foregoing embodiments may be combined with any one or more of the other foregoing embodiments to create a new embodiment within the scope of the present disclosure.

[0042] These and other features will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings and claims.BRIEF DESCRIPTION OF THE DRAWINGS

[0043] For a more complete understanding of this disclosure, reference is now made to the following brief description, taken in connection with the accompanying drawings and detailed description, wherein like reference numerals represent like parts.

[0044] FIG. 1 illustrates a side cross-sectional view of a tandem perovskite single crystal, high- resolution, flexible color image sensor structure according to an embodiment of the present disclosure.

[0045] FIGS. 2A-2C illustrates top views of pixel array layers in a tandem perovskite single crystal, high-resolution, flexible color image sensor structure according to an embodiment of the present disclosure.

[0046] FIG. 3 illustrates a side cross-sectional view of another tandem perovskite single crystal, high-resolution, flexible color image sensor structure according to an embodiment of the present disclosure.

[0047] FIG. 4 illustrates a side cross-sectional view of yet another tandem perovskite single crystal, high-resolution, flexible color image sensor structure according to an embodiment of the present disclosure.

[0048] FIG. 5 illustrates an example method of providing a perovskite single crystal image sensor structure according to an embodiment of the present disclosure.

[0049] FIGS. 6A-6C illustrate an example method of providing a tandem perovskite single crystal, high-resolution, flexible color image sensor structure according to an embodiment of the present disclosure.

[0050] FIG. 7 illustrates another example method of providing a perovskite single crystal image sensor structure according to an embodiment of the present disclosure.

[0051] FIGS. 8A-8B illustrate yet another example method of providing a perovskite single crystal image sensor structure according to an embodiment of the present disclosure.

[0052] FIG. 9 illustrates a side cross-sectional view of an electronic device including a tandem perovskite single crystal, high-resolution, flexible color image sensor structures according to an embodiment of the present disclosure.

[0053] FIG. 10 is a flowchart of an example method of providing a tandem perovskite single crystal, high-resolution, flexible color image sensor structures according to an embodiment of the present disclosure.DETAILED DESCRIPTION

[0054] It should be understood at the outset that although an illustrative implementation of one or more embodiments is provided below, the disclosed systems and / or methods may be implemented using any number of techniques, whether currently known or in existence. The disclosure should in no way be limited to the illustrative implementations, drawings, and techniques illustrated below, including the exemplary designs and implementations illustrated and described herein, but may be modified within the scope of the appended claims along with their full scope of equivalents.

[0055] The following terms are defined as follows unless used in a contrary context herein. Specifically, the following definitions are intended to provide additional clarity to the presentdisclosure. However, terms may be described differently in different contexts. Accordingly, the following definitions should be considered as a supplement and should not be considered to limit any other definitions of descriptions provided for such terms herein.

[0056] The digital image processing technology market is experiencing significant growth, driven by the increasing adoption of computer vision, artificial intelligence (Al), and machine learning across various industries (e.g., healthcare, security, manufacturing, retail, e-commerce, entertainment, education, etc.). As such, there is an increasing demand for high-resolution, high- quality color imaging devices and / or systems. One type of image sensor that is commonly used in electronic devices is complementary metal oxide semiconductor (CMOS) image sensors. In a CMOS image sensor, the light-sensing semiconductor material that converts light (e.g., photons) into electrical charge (e.g., electrons) may be made of silicon. To provide color image sensing, a CMOS image sensor may include a color filter that detects different colors of light. A commonly used color filter is Bayer filter, which may include a mosaic or checkerboard pattern of red, green, and blue color filters with twice as many green filters as red or blue (e.g., due to human vision being more sensitive to green light). As such, a group of four-color filters (e.g., two green, one red, and one blue) is needed to sense the different light colors. In an example, each color filter may correspond to a single pixel. That is, four pixels are needed to sense the different light colors, thereby limiting the resolution of color image sensing. Further, because a group of four pixels is required for color sensing, a CMOS color image sensor may further include a micro-lens to focus incoming light onto the light-sensitive element within each pixel to maximize light capture.

[0057] Recent studies show that perovskite materials have desirable optoelectronic properties, such as a high or large photo response (e.g., providing high photosensitivity) and tunable optical bandgaps (e.g., tuned to absorb light in a particular wavelength range in a visible or invisible light spectrum). As such, it may be desirable to use perovskite materials as an alternative to silicon for image sensors. Perovskite may refer to calcium titanate mineral (CaTiCh), or generally, to a class of chemical compounds having the same type of crystal structure as CaTiCh. That is, a perovskite material may be composed of a chemical compound described by a general chemical formula: ABX3, where A and B may be cations and X may be anions.

[0058] While it may be desirable to use perovskite materials as light-sensitive elements in an image sensor, there are various challenges in fabricating an array of perovskite single crystal elements that can provide high-resolution, high-quality image sensing. For instance, a solutionprocess is widely used for fabricating perovskite material (e.g., for solar cells and other optoelectronic devices). The solution process may involve dissolving perovskite pre-cursor chemicals into a solution, coating the solution onto a substrate, and then drying and annealing the solution-coated substrate to form a perovskite fdm on the substrate. However, perovskite fabricated from a solution process may generally have grainy boundaries where multiple small crystals are joined together, voids, and / or surface imperfections. These defects and recombination sites may result in a significant efficiency loss (e.g., in terms of photosensitivity) and thus may not provide high-quality image sensing.

[0059] Various approaches have attempted to form perovskite crystal arrays. For instance, one approach forms a perovskite single crystal array by defining an array of cavities in a substrate for dropping or depositing the perovskite solution. However, the resulting single crystal perovskite material is formed near the corners and / or edges of the defined locations or cavities instead of evenly distributed throughout the defined cavities or locations (that are needed for high-quality imaging). Another approach forms an array of perovskite pixels on a flexible substrate using solution-processed multi-crystalline perovskite, not single crystal perovskite. Another approach forms a perovskite single crystal array by spin-coating a pre-patterned glass substrate with a perovskite solution but the perovskite material in the pixels is not in a single crystal structure and the array is not flexible. Generally, it may be difficult and complicated to control the locations, the sizes, and / or the quality of each single piece of perovskite in an array. Thus, it may be challenging to grow an array of high- quality small perovskite single crystal elements using the solution process. More recently, one approach is successful in forming a large piece of perovskite single crystal wafer by applying a well- controlled temperature and top-seeded solution growth process.

[0060] With the proliferation of wearable electronics devices and the continued emerging imaging applications, it may be desirable to have flexible image sensors on those devices (e.g., especially those that are focused on health and wellness monitoring, such as smartwatches, fitness trackers, smart glasses, etc., and / or medically related, such as electronic skin patches, etc.). While a large perovskite single crystal wafer can be fabricated, the large perovskite single crystal wafer is not flexible. Furthermore, there is a growing demand for smaller-sized and higher-performance image sensors for electronic devices. Accordingly, there is a need to improve image sensor technology.

[0061] Disclosed herein are techniques for providing high-resolution, high-sensitivity, flexible color image sensors using perovskite single crystal materials. More specifically, an image sensor array may include an array of pixel elements (e.g., light-sensitive elements) fabricated from a high- quality perovskite single crystal wafer using lithography. A high-quality perovskite single crystal wafer may refer to a thin, flat piece of perovskite material, where the entire structure is a single, continuous crystal lattice without grain boundaries or other defects. Perovskite materials have a high photosensitivity, allowing for smaller sized and / or thinner pixel elements compared to CMOS image sensors. Lithography can provide precise patterning of elements with high-accuracy and precise controls of shapes, sizes, and / or spacings, thus allowing for uniform small-sized (e.g., less than 20 micrometers (pm) by 20 pm), uniformly shaped, uniformly and closely spaced pixel elements in the array. Using perovskite single crystal material as the light-sensitive elements and lithography for patterning may together provide high-resolution, high-sensitivity image sensors (e g., a greater number of pixel elements in the same area). Additionally, the array of perovskite single crystal pixel elements may be formed on a flexible encapsulation or substrate layer to provide a flexible image sensor suitable for various electronic devices (e.g., wearable electronics or non-flat image sensors). Further, multiple pixel element arrays, each made of a perovskite material tuned to absorb a different color light (e.g., red, blue, and green lights), may be stacked to form a tandem color image sensor, eliminating the need for a complex color filter and additional micro-lens as in CMOS image sensors. The pixel elements in the arrays may be aligned so that different colors of light (e.g., red, blue, and green) may be sensed within a single pixel region rather than requiring multiple pixel regions as in the Bayer color filter, thereby allowing for high- resolution (e.g., 20 or more megapixels) color image sensing.

[0062] FIG. 1 illustrates a side cross-sectional view of a tandem perovskite single crystal, high- resolution, flexible color image sensor structure 100 according to an embodiment of the present disclosure. The side cross-sectional view is in a y-z plane along line A-A of FIG. 2A. In an embodiment, the color image sensor structure 100 (e.g., an integrated circuit (IC) structure) is part of an electronic device (e.g., as shown in FIG. 9). At a high level, the color image sensor structure 100 may capture light 101 (e.g., reflected off an object or a scene) and convert the captured light into electrical signals for forming a digital color image. As shown in FIG. 1, the color image sensor structure 100 may include a plurality of multilayer stacked structures 112 (individually shown as 112a, 112b, and 112c) stacked along the direction of the z-axis (e.g., the propagation direction ofthe light 101). Each multilayer stacked structure 112 may include a pixel array layer 1 14 and an electrode layer 116 between two encapsulation layers 102 (e.g., which also be referred to as barrier layers or substrate layers). More specifically, the pixel array layer 114 may be between a first encapsulation layer 102-1 (e.g., atop encapsulation layer 102) and the electrode layer 116, and the electrode layer 116 may be between the pixel array layer 114 and a second encapsulation layer 102-2 (e.g., a bottom encapsulation layer 102). Stated differently, each multilayer stacked structure 112 may include a first encapsulation layer 102-1, a pixel array layer 114, an electrode layer 116, and a second encapsulation layer 102-2 arranged in order along the direction of the z-axis. For simplicity, FIG. 1 only illustrates the encapsulation layer 102-1, the pixel array layer 114, the electrode layer 116, and the second encapsulation layer 102-2 with their respective reference numerals for the multilayer stacked structure 112a.

[0063] Each pixel array layer 114 may include a plurality of pixel elements 104. For instance, the pixel array layer 114 in the multilayer stacked structure 112a may include a plurality of pixel elements 104a, the pixel array layer 114 in the multilayer stacked structure 112c may include a plurality of pixel elements 104b, and the pixel array layer 114 in the multilayer stacked structure 112c may include a plurality of pixel elements 104c. Each pixel element 104 may include a perovskite single crystal material. As will be discussed more fully below with reference to FIGS. 5, 6A-6C, 7, and 8A-8B, the pixel elements 104 in each pixel array layer 114 are formed from a perovskite single crystal wafer using lithography. For simplicity, FIG. 1 only illustrates two pixel elements 104 along the y-axis in each pixel array layer 1 12. However, each pixel array layer 1 12 may include any suitable number of pixel elements 104 (e.g., 64, 128, 1024, 4096 or more) along the y-axis.

[0064] As discussed above, a perovskite material may include a chemical compound described by a general chemical formula: ABX3. In an example, A in the chemical formula comprises at least one of methylammonium ion (MA+), formamidinium cation (FA+), caesium ion (Cs+), calcium ion (Ca2+), or strontium ion (Sr2), B in the chemical formula comprises at least one of lead (II) ion (Pb2+), tin (II) ion (Sn2+), titanium(IV) cation (Ti4+), niobium(V) ion (Nb5+), or manganese (IV) cation (Mn4+), and C in the chemical formula comprises at least one of oxygen (O2), fluoride ion (F‘ ), chloride ion (O'), bromide ion (Br ), or iodide ion (F).

[0065] As further discussed above, the composition or chemical compound (e.g., represented by a chemical formula ABX3) in a perovskite material can be tuned or adjusted to provide differentwavelengths or bands of light absorption. In an embodiment, the color image sensor structure 100 provides color image sensing by using perovskite materials with different wavelengths of light absorption for the pixel elements 104 in different pixel array layers 114 or different multilayer stacked structures 112. That is, the perovskite single crystal material in the plurality of pixel elements 104a in the multilayer stacked structure 112a may include a first perovskite chemical compound that absorbs an optical signal in a first wavelength range. The perovskite single crystal material in the plurality of pixel elements 104b in the multilayer stacked structure 112b may include a first perovskite chemical compound that absorbs an optical signal in a second wavelength range different than the first wavelength range. The perovskite single crystal material in the plurality of pixel elements 104c in the multilayer stacked structure 112c may include a first perovskite chemical compound that absorbs an optical signal in a third wavelength range different than the first and second wavelength ranges. FIG. 1 illustrates the different perovskite materials or different perovskite chemical compounds in the pixel elements 104a, 104b, and 104c by using different patterned boxes.

[0066] In an embodiment, the pixel elements 104a in the multilayer stacked structure 112a may be tuned to absorb blue color light (e.g., with wavelengths between about 450 nanometers (nm) and 495 nm). The pixel elements 104b in the multilayer stacked structure 112b may be tuned to absorb green color light (e.g., with wavelengths between about 495 nm and 570 nm), and the pixel elements 104c in the multilayer stacked structure 112c may be tuned to absorb red color light (e.g., with wavelengths between about 620 nm and 750 nm). As an example, the pixel elements 104a may include methylammonium lead chloride bromide (MAPb(Cli,5Bri,5)) to absorb blue color light, the pixel elements 104b may include methylammonium lead bromide (MAPb(Br3)) to absorb green color light, and the pixel elements 104c may include methylammonium lead bromideiodide (MAPb(Brl2)) to absorb red color light. Generally, the perovskite materials in the pixel elements 104 may be selected to provide light absorption in the visible light spectrum or the invisible light spectrum. As will be discussed more fully below with reference to FIG. 9, the pixel elements 104 may be aligned across the pixel array layers 114 to provide color image sensing per pixel instead of per 4 pixels as in the Bayer color filter discussed above, thereby providing a higher color image sensing resolution than when using the Bayer color filter.

[0067] Each electrode layer 116 is coupled to a corresponding pixel array layer 114. More specifically, each electrode layer 116 may include a plurality of transparent electrode elements 110,where each adjacent pair of transparent electrode elements 110 may correspond, align, and coupled to a respective one of the pixel element 104. A more detailed view is shown by 109. For instance, a pair of adjacent transparent electrode elements 110 may include a first transparent electrode element 110-1 and a second transparent electrode element 110-2 aligned to opposite sides 106-1 and 106-2 of a corresponding pixel element 104-1. The transparent electrode elements 110-1 and 110-2 may be in physical contact with the corresponding pixel element 104-1. The pixel element 104-1 may act as a channel between the transparent electrode elements 110-1 and 110-2.

[0068] In the illustrated example of FIG. 1, the transparent electrode elements 110 may include the same semiconductor materials, where the pixel element 104-1 and the pair of adjacent transparent electrode elements 110-1 and 110-2 together form a photoconductor device 118 (shown by the thick dash-lined box) for light sensing. In a photoconductor, light-generated carriers (e.g., generated by the perovskite single crystal material in the pixel element 104-1 responsive to the light 101) are separated by an externally applied bias voltage and then collected at each of the electrode elements 110-1 and 110-2. In this device structure, one type of carrier (e.g., holes) is typically trapped in the trap center with a longer lifetime. Meanwhile, another type of carrier (e.g., electrons) can be recirculated through an external circuit until it recombines with the opposite carrier, thus yielding a photoconductive gain. That is, the electrical conductivity provided by the pixel elements 104 in the photoconductor device 118 may be proportional to the intensity of the incident light 101. Generally, the transparent electrode elements 110 may include a transparent electrode material, for example, including, but not limited to, indium tin oxide (ITO), transparent conductive oxide (TCO), conducting polymers, carbon-based nanomaterials (e.g., including carbon nanotube and graphene or conducting nanowire networks and / or metal mesh). The transparent electrode material may allow incident light 101 to pass through from one multilayer stacked structure 112 to another multilayer stacked structure 112.

[0069] The encapsulation layer 102 may act as a barrier and a substrate for each multilayer stacked structure 112. To provide a flexible or bendable device structure, the first encapsulation layer 110-1 and the second encapsulation layer 110-2 may include a flexible or soft material, for example, including, but not limited to, parylene-C, PMMA, polyimide, polyester, silicon rubbers, urethane rubbers, epoxy resins, epoxy-based photoresist (e.g., SU-8 photoresist), or amorphous fluoropolymer (e.g., CYTOP® where the chemical name may be poly 1,1, 2, 4, 4, 5, 5, 6, 7, 7 - decafluor -3 -oxa- 1 ,6-heptadiene) .

[0070] In an embodiment, each pixel element 104 may have a thickness 120 between about 0.1 pm and 2 pm or between about 0.3 pm and 0.5 pm. In some embodiments, the pixel elements 104 in the different pixel array layers 114 may have the same thickness 120. In other embodiments, the pixel array layer in the different pixel array layers 114 may have different thicknesses 120. In an embodiment, each transparent electrode element 110 may have a thickness 122 between about 0.01 pm and 0.5 pm. In an embodiment, each encapsulation layer 102 may have a thickness 124 between about 0.05 pm and 2 pm.

[0071] FIGS. 2A-2C illustrates top views of the pixel array layers 114 in the tandem perovskite single crystal, high-resolution, flexible color image sensor structures 100 according to an embodiment of the present disclosure. The top views are in an x-y plane. FIG. 2A illustrates an array 210a of perovskite single crystal pixel element 104a in the pixel array layer 114 of the multilayer stacked structure 112a. FIG. 2B illustrates an array 210b of perovskite single crystal pixel element 104b in the pixel array layer 114b of the multilayer stacked structure 112b. FIG. 2C illustrates an array 210c of perovskite single crystal pixel element 104c in the pixel array layer 114 of the multilayer stacked structure 112c. The pixel elements 104 in each array 210 may generally be arranged in a regular or uniform pattern of rows and columns (e.g., a matrix array or a grid) corresponding to an image to be generated. Each pixel element 104 (e.g., the light-sensitive elements) may correspond to a pixel in the generated image.

[0072] To provide a high-resolution and high-quality image sensing, the pixel elements 104 in an array 210 may have the same size, same dimensions, and same shape and a high pixel density. For simplicity, FIGS. 2A-2C illustrate each array 210 including eight pixel elements 104. However, each array 210 may include any suitable number of pixel elements 104 (e.g., each row and each column may have 1024, 2048, 2096 or more number of pixel elements 104). In an embodiment, each pixel element 104 may have a square shape and may be less than about 25 pm*25 pm, 22 pm*22 pm, or 20 pm*20 pm. Generally, the pixel element 104 can be in any suitable shape. In an embodiment, each pixel element 104 may have a width 202 and / or a length 204 that is less than about 25 pm. Further, the pixel elements 104 in each pixel array layer 114 may be uniformly spaced from one another. In an embodiment, a pitch 206 between two adjacent pixel elements 104 may be between about 0.2 pm and 25 pm or between about 0.3 pm and 20 pm.

[0073] As discussed above, each pair of adjacent transparent electrode elements 110 correspond to a respective pixel element 104 in the same multilayer stacked structure 112. As such,the transparent electrode elements 110 in each electrode layer 1 16 may also be arranged in a matrix array or grid similar to the arrays 210. However, the number of transparent electrode elements 110 in each electrode layer 116 may have twice the number of pixel elements 104 in a corresponding pixel array layer 114.

[0074] FIG. 3 illustrates a side cross-sectional view of another tandem perovskite single crystal, high-resolution, flexible color image sensor structure 300 according to an embodiment of the present disclosure. The color image sensor structure 300 may be substantially similar to the color image sensor structure 100. However, the color image sensor structure 300 may use photodiode devices (e.g., a photodiode device 318 shown by the thick dash-lined box) for light sensing instead of photoconductor devices 118 as in color image sensor structure 100. The side cross-sectional view in FIG. 3 is in a y-z plane similar to the side cross-sectional view of FIG. 1. For simplicity, FIG. 3 only shows one photodiode device with the reference numeral 318. Further, FIG. 3 may use the same reference numerals to refer to the same layers and / or elements as in FIG. 1 and FIGS. 2A-2B.

[0075] As shown in FIG. 3, the color image sensor structure 300 may include a plurality of multilayer stacked structures 312 (individually shown as 312a, 312b, and 312c) stacked along the direction of the z-axis (e.g., the propagation direction of the light 101). Each multilayer stacked structure 312 may include a pixel array layer 114 and an electrode layer 316 between two encapsulation layers 102 (e g., a top encapsulation layer 102-1 and a bottom encapsulation layer 102-2). The electrode layer 316 may include a plurality of alternating transparent electrode elements 110 and 310. To provide a photodiode device 318, the transparent electrode elements 110 and 310 may include different semiconductor materials. Example electrode materials may include gold (Au), platinum (Pt), titanium (Ti), copper (Cu), graphene, and / or ITO. The electrical signal (e.g., photocurrent) generated by the photodiode device 318 may be proportional to the intensity of the incident light 101. Generally, the transparent electrode elements 110 and 310 may have the same dimensions as the transparent electrode element 110 discussed above with reference to FIG. 1.

[0076] FIG. 4 illustrates a side cross-sectional view of yet another tandem perovskite single crystal, high-resolution, flexible color image sensor structure 400 according to an embodiment of the present disclosure. The color image sensor structure 400 may be substantially similar to the color image sensor structure 100. However, the color image sensor structure 400 may use phototransistor devices (e.g., a phototransistor device 418 shown by the thick dash-lined box) forlight sensing instead of photoconductor devices 118 as in color image sensor structure 100. The side cross-sectional view in FIG. 4 is in a y-z plane similar to the side cross-sectional view of FIG. 1. For simplicity, FIG. 4 only shows one phototransistor device with reference numeral 418. Further, FIG. 4 may use the same reference numerals to refer to the same layers and / or elements as in FIG. 1 and FIGS. 2A-2B.

[0077] As shown in FIG. 4, the color image sensor structure 400 may include a plurality of multilayer stacked structures 412 (individually shown as 412a, 412b, and 412c) stacked along the direction of the z-axis (e.g., the propagation direction of the light 101). Each multilayer stacked structure 412 may include a pixel array layer 114 and an electrode layer 116 between two encapsulation layers 102 (e.g., a top encapsulation layer 102-1 and a bottom encapsulation layer 102-2). In contrast to the color image sensor structure 100, the color image sensor structure 400 may further include a gate electrode layer 402 and a gate dielectric layer 404 between the pixel array layer 114 and the encapsulation layer 102-1 in each multilayer stacked structure 412 to provide phototransistor devices 418. More specifically, the gate electrode layer 402 may be between the encapsulation layer 102-1 and the gate dielectric layer 404, and the gate dielectric layer 404 may be between the gate electrode layer 402 and the pixel array layer 114.

[0078] The gate electrode layer 402 may include a plurality of gate electrode elements 406, each corresponding to and aligned to a corresponding pixel element 104. In some embodiments, the gate electrode elements 406 may include the same semiconductor material as the transparent electrode elements 110. In other embodiments, the gate electrode elements 406 may include a different semiconductor material than the transparent electrode elements 110. Example gate electrode materials may include chromium (Cr), Cr / Aluminum (Al), indium (III) selenide (In2Sea), strontium molybdenum oxides (S MosOio), and / or hafnium dioxide (HfCh) In an embodiment, each gate electrode element 406 may have a thickness 420 between about 10 and 200 nanometers (nm). In contrast to the photoconductor device 118 of FIG. 1, an external voltage can be applied to the gate electrode element 406 to modulate the semiconductor channel provided by the respective pixel element 104, thus regulating the channel conductivity and suppressing the dark current. As such, the phototransistor device 418 may provide lower noise and a higher conductivity gain compared to the photoconductor device 118, thereby providing a higher photosensitivity than the photoconductor device 118.

[0079] The gate dielectric layer 404 may include a plurality of dielectric elements 408, each corresponding to and aligned to a corresponding pixel element 104. Each dielectric element 408 may be in contact with a corresponding pixel element 104 and a corresponding gate electrode element 406. The gate dielectric elements 408 are a thin insulating layer for separating the respective gate electrode element 406 from the respective pixel element 104 (e.g., to prevent direct current flow from gate electrode element 406 to the pixel element 104). In an embodiment, each dielectric element 408 may have a thickness 422 between about 1 and 150 nm. In an embodiment, each dielectric element 408 may include a semiconductor material, for example, including, but not limited to, silicon dioxide (SiCh), polyvinylpyrrolidone (PVP), HfCh, aluminum oxide (AI2O3). In some embodiments, the gate dielectric layer 404 may be optional. That is, the gate electrode layer 402 may be adjacent to and in contact with the pixel array layer 114.

[0080] FIG. 5 illustrates an example method 500 of fabricating a perovskite single crystal image sensor structure 528 according to an embodiment of the present disclosure. The perovskite single crystal image sensor structure 528 includes photoconductor devices (e.g., photoconductor device 118) for light sensing. In an embodiment, the perovskite single crystal image sensor structure 528 may correspond to a single multilayer stacked structure 112 that senses light in a particular wavelength range. The perovskite single crystal image sensor structure 528 may be used to form a tandem color image sensor structure 100 as will be discussed more fully below with reference to FIGS. 6A-6C. In another embodiment, the perovskite single crystal image sensor structure 528 may be used alone as a perovskite monochromatic image sensor. The method 500 is illustrated using cross-sectional side views of IC structures at various fabrication steps in a z-y plane. For simplicity, FIG. 5 may use the same reference numerals to refer to the same layers and / or elements as in FIG. 1.

[0081] As shown in FIG. 5, the method 500 includes a perovskite single crystal array (e.g., the arrays 210) fabrication process 504 and an electrode array fabrication process 506. In the process 504, a carrier substrate layer 502-1 may be provided. The carrier substrate layer 502-1 may operate as a support substrate for fabricating a perovskite single crystal array (e.g., the array 210). In some examples, the carrier substrate layer 502-1 may include silicon. The carrier substrate layer 502-1 may generally include any suitable semiconductor material. At operation 530, a flexible encapsulation layer 102-1 is formed on the substrate layer 502-1 (e.g., using a chemical vaporization deposition (CVD) process, a physical vapor deposition (PVD) process, or any othersuitable semiconductor fabrication process) to form a structure 512. At operation 532, a perovskite single crystal wafer 508 is transferred onto the structure 512, or more specifically, on a plane or surface of the flexible encapsulation layer 102-1 in an x-y plane (e.g., using a wafer transfer process) to form a structure 514. The perovskite single crystal wafer 508 may be formed using any suitable process (e.g., a temperature-controlled and top-seeded growth solution process. At operation 534, the perovskite single crystal wafer 508 is patterned into an array of perovskite single crystal pixel elements 104 (e.g., similar to the arrays 210) using a lithography process (e.g., photolithography or electron-beam lithography) to form a structure 516. Generally, the perovskite single crystal pixel elements 104 in the array may have a regular, uniform pattern of rows and columns (e.g., similar to the arrays 210 shown in FIG. 2). In some examples, the array may include between about 460 and 12000 number of rows and between about 3000 and 9000 number of columns to allow for a high-resolution digital image to be generated.

[0082] In the process 506, a carrier substrate layer 502-2 may be provided. The carrier substrate layers 502-1 and 502-2 may be collectively referred to as 502 in the discussions below. At operation 540, a flexible encapsulation layer 102-2 is formed on the substrate layer 502-2 (e.g., using a CVD or PVD process) to form a structure 522. At operation 542, an array of transparent electrode elements 110 is formed on the encapsulation layer 102-2 (e.g., using an electrode patterning process, such as lithography, or any other suitable semiconductor fabrication process) to form a structure 524.

[0083] Next, at operation 550, the structure 516 and the structure 524 are combined to form a structure 526. For instance, the structure 516 (with the perovskite single crystal pixel elements 104) is flipped (e.g., along the z-axis) and transferred onto a surface (e.g., an x-y plane) of the structure 524 such that the perovskite single crystal pixel elements 104 are facing (e.g., in contact with) and in alignment with corresponding transparent electrode elements 110. At operation 552, the carrier substrate layers 502 (e.g., 502-1 and 502-2) of the structure 526 are removed or delaminated (e.g., using a chemical solution or a mechanical process) to form the perovskite single crystal image sensor structure 528 (e.g., a free-standing flexible image sensor).

[0084] FIGS. 6A-6C illustrate an example method 600 of fabricating a tandem perovskite single crystal, high-resolution, flexible color image sensor structure 642 according to an embodiment of the present disclosure. In an embodiment, the color image sensor structure 642 may correspond to the color image sensor structure 100. The method 600 is illustrated using cross-sectional sideviews of IC structures at various steps in a z-y plane. For simplicity, FIG. 6 may use the same reference numerals to refer to the same layers and / or elements as in FIGS. 1 and 5.

[0085] Turning now to FIG. 6A, various perovskite single crystal image sensor structures 610, 612, and 614 similar to the perovskite single crystal image sensor structure 528 may be provided. For example, each of the perovskite single crystal image sensor structures 610, 612, and 614 may be fabricated using the method 500. Each perovskite single crystal image sensor structures 610, 612, and 614 may include pixel elements 104 patterned from a perovskite single crystal wafer (e.g., the perovskite single crystal wafer 508) composed of a different perovskite chemical compound for absorption of a different color light. For example, the perovskite single crystal image sensor structure 610 may include pixel elements 104c patterned from a perovskite single crystal wafer including a perovskite chemical compound that absorbs red color light. The perovskite single crystal image sensor structure 612 may include pixel elements 104b patterned from a perovskite single crystal wafer including a perovskite chemical compound that absorbs green color light. The perovskite single crystal image sensor structure 614 may include pixel elements 104a patterned from a perovskite single crystal wafer including a perovskite chemical compound that absorbs blue color light.

[0086] At operation 601, the carrier substrate layer 502-1 (e.g., the top carrier substrate layer) of the structure 610 is removed or delaminated to form a structure 620. At operation 602, the carrier substrate layer 502-2 (e.g., the bottom carrier substrate layer) of the structure 612 is removed or delaminated to form a structure 622. At operation 603, the carrier substrate layer 502-2 (e.g., the bottom carrier substrate layer) of the structure 614 is removed or delaminated to form a structure 624.

[0087] Turning now to FIG. 6B, at operation 604, the structure 620 is flipped (e.g., along the z-axis) and transferred onto a surface (e.g., an x-y plane) of the structure 622 such that the flexible encapsulation layer 102-2 of the structure 622 is adjacent to (e.g., in contact with) the flexible encapsulation layer 102-1 of the structure 620 to form a structure 630. At operation 605, the top carrier substrate layer 502-2 of the structure 630 (e.g., the carrier substrate layer 502-1 of the structure 620) is removed or delaminated to form a structure 632.

[0088] Turning now to FIG. 6C, at operation 606, the structure 624 is transferred onto a surface (e.g., an x-y plane) of the structure 632 such that the flexible encapsulation layer 102-2 of the structure 624 is adjacent to (e.g., in contact with) the flexible encapsulation layer 102-1 of thestructure 632 to form a structure 640. At operation 607, the carrier substrate layers 502-1 and 502-2 of the structure 640 is removed or delaminated to form a tandem perovskite single crystal, high- resolution, flexible color image sensor structure 642.

[0089] FIGS. 6A-6C are merely an example of method 600 for fabricating a color image structure 628, and variations are contemplated to be within the scope of the present disclosure. In some embodiments, the structure 612 and 614 may be combined before combining the structure 610. In such embodiments, the removals of the carrier substrate layer 502 in the structures 610, 612, and 614 may occur in a different order than the method 600 illustrated in FIGS. 6A-6C. Such and other embodiments are contemplated to be within the scope of the present disclosure.

[0090] FIG. 7 illustrates an example method 700 of providing a perovskite single crystal image sensor structure 728 according to an embodiment of the present disclosure. The perovskite single crystal image sensor structure 728 includes photodiode devices (e.g., photodiode device 318) for light sensing. In an embodiment, the perovskite single crystal image sensor structure 728 may correspond to a single multilayer stacked structure 312 that senses light in a particular wavelength range. The perovskite single crystal image sensor structure 728 may be used to form a tandem color image sensor structure 300 (e.g., using the method 600 of FIGS. 6A-6C). In another embodiment, the perovskite single crystal image sensor structure 728 may be used alone as a perovskite monochromatic image sensor. The method 700 is illustrated using cross-sectional side views of IC structures at various steps in a z-y plane. For simplicity, FIG. 7 may use the same reference numerals to refer to the same layers, elements, and / or structures as in FIGS. 1 , 3 and 5.

[0091] The method 700 includes a perovskite single crystal array fabrication process 704 and an electrode array fabrication process 706. Generally speaking, the method 700 includes features similar to method 500 in many respects. For instance, the operations 730, 732, 734, 740, 750, and 752 may be similar to the operations 530, 532, 534, 540, 550, and 552, respectively. Accordingly, for brevity, details of those operations will not be repeated here.

[0092] As discussed above, the color image sensor structure 300 is similar to the color image sensor structure 100 but may include photodiode devices 318 instead of photoconductor devices 118 as in the color image sensor structure 100. As further discussed above, the two electrode elements (e.g., the transparent electrode elements 110) in a photoconductor device 118 may include the same semiconductor materials, whereas the two electrode elements (e.g., the transparent electrode elements 110 and 310) in a photodiode device 318 may include differentsemiconductor materials. Accordingly, at operation 742, an array of alternating transparent electrode elements 110 and 310 are formed on the flexible encapsulation layer 102-2 (e.g., using an electrode patterning process, such as lithography, or any other suitable semiconductor fabrication process) to form a structure 724. In an example, each row in the electrode element array may include alternating transparent electrode elements 110 and 310, and each column may include transparent electrode elements 110 or 310. In another example, each column in the electrode element array may include alternating transparent electrode elements 110 and 310, and each row may include transparent electrode elements 110 or 310.

[0093] Subsequently, at operation 750, the structure 516 and the structure 724 are combined to form a structure 726. For instance, the structure 516 (with the perovskite single crystal pixel elements 104) is flipped (e.g., along the z-axis) and transferred onto a surface (e.g., an x-y plane) of the structure 724 such that the perovskite single crystal pixel elements 104 are facing (e.g., in contact with) and in alignment with corresponding transparent electrode elements 110 and 310. At operation 752, the carrier substrate layers 502 (e.g., 502-1 and 502-2) of the structure 726 are removed or delaminated (e.g., using a chemical solution or a mechanical process) to form the perovskite single crystal image sensor structure 728 (e.g., a free-standing flexible image sensor).

[0094] In an embodiment, each of the multilayer stacked structures 312a, 312b, and 312c of the color image structure 300 of FIG. 3 may be fabricated using the method 700. The pixel elements 104c in the multilayer stacked structure 312c may be patterned from a perovskite single crystal wafer including a perovskite chemical compound that absorbs red color light. The pixel elements 104b in the multilayer stacked structure 312b may be patterned from a perovskite single crystal wafer including a perovskite chemical compound that absorbs green color light. The pixel elements 104a in the multilayer stacked structure 312a may be patterned from a perovskite single crystal wafer including a perovskite chemical compound that absorbs blue color light. The multilayer stacked structures 312a, 312b, and 312c may be stacked using the method 600 as discussed above with reference to FIGS. 6A-6C to form the color image sensor structure 300.

[0095] FIGS. 8A-8B illustrate an example method of providing a perovskite single crystal image sensor structure 828 according to an embodiment of the present disclosure. The perovskite single crystal image sensor structure 828 includes phototransistor devices (e.g., phototransistor device 318) for light sensing. In an embodiment, the perovskite single crystal image sensor structure 828 may correspond to a single multilayer stacked structure 412 that senses light in aparticular wavelength range. The perovskite single crystal image sensor structure 828 may be used to form a tandem color image sensor structure 400 (e.g., using the method 600 of FIGS. 6A-6C). In another embodiment, the perovskite single crystal image sensor structure 828 may be used alone as a perovskite monochromatic image sensor. The method 800 is illustrated using cross-sectional side views of IC structures at various steps in a z-y plane. For simplicity, FIGS. 8A-8B may use the same reference numerals to refer to the same layers, elements, and / or structures as in FIGS. 1, 4 and 5.

[0096] The method 800 includes a perovskite single crystal array fabrication process 804 and an electrode array fabrication process 806. Generally speaking, the method 800 includes features similar to method 500 in many respects. For instance, the operations 830, 840, and 842 may be similar to the operations 530, 540, and 542, respectively. Accordingly, for brevity, details of those operations will not be repeated here.

[0097] Turning now to FIG. 8A, at operation 832, a gate electrode layer 806 is deposited on the structure 512, or more specifically, on a surface of the flexible encapsulation layer 102-1 in an x-y plane (e.g., using an electrodeposition or electroplating process) to form a structure 814. The gate electrode layer 806 may include any suitable semiconductor conductive material. At operation 834, a gate dielectric layer 808 is formed on the structure 814, or more specifically, on a surface of the gate electrode layer 806 in an x-y plane (e.g., using an electrodeposition or electroplating process) to form a structure 815. The gate dielectric layer 808 may include any suitable semiconductor dielectric material. At operation 836, a perovskite single crystal wafer 508 is transferred onto the structure 815, or more specifically, on a surface of the gate dielectric layer 808 in an x-y plane (e.g., using a wafer transfer process) to form a structure 816. At operation 838, the perovskite single crystal wafer 508, the gate dielectric layer 808, and the gate electrode layer 806 may be patterned respectively into an array of perovskite single crystal pixel elements 104, an array of gate dielectric elements 408, and an array of gate electrode elements 406 using a lithography process (e.g., photolithography or electron-beam lithography) to form a structure 817. As shown, each gate electrode element 406 is aligned to a respective one of the gate dielectric elements 408 and a respective one of the pixel elements 408.

[0098] Turning now to FIG. 8B, at operation 850, the structure 817 and the structure 524 are combined to form a structure 826. For instance, the structure 817 (with the perovskite single crystal pixel elements 104) is flipped (e.g., along the z-axis) and transferred onto a surface (e.g., an x-yplane) of the structure 524 such that the perovskite single crystal pixel elements 104 are facing (e.g., in contact with) and in alignment with corresponding transparent electrode elements 110. At operation 852, the carrier substrate layers 502 (e.g., 502-1 and 502-2) of the structure 826 are removed or delaminated (e.g., using a chemical solution or a mechanical process) to form the perovskite single crystal image sensor structure 828 (e.g., a free-standing flexible image sensor).

[0099] In an embodiment, each of the multilayer stacked structures 412a, 412b, and 412c of the color image structure 400 of FIG. 4 may be fabricated using the method 800. The pixel elements 104c in the multilayer stacked structure 412c may be patterned from a perovskite single crystal wafer including a perovskite chemical compound that absorbs red color light. The pixel elements 104b in the multilayer stacked structure 412b may be patterned from a perovskite single crystal wafer including a perovskite chemical compound that absorbs green color light. The pixel elements 104a in the multilayer stacked structure 412a may be patterned from a perovskite single crystal wafer including a perovskite chemical compound that absorbs blue color light. The multilayer stacked structures 412a, 412b, and 412c may be stacked using the method 600 as discussed above with reference to FIGS. 6A-6C to form the color image sensor structure 400.

[0100] FIG. 9 illustrates a side cross-sectional view of an electronic device 900 including a tandem perovskite single crystal, high-resolution, flexible color image sensor structure 100 according to an embodiment of the present disclosure. The side cross-sectional view is in a y-z plane. In some examples, the electronic device 900 may be a wearable device, a health and / or wellness monitoring device, a smartphone, a gaming device, etc. As shown in FIG. 9, the electronic device 900 may further include lens 910 and CMOS digital circuitry 920. The lens 910 may direct and / or focus incoming light 902 onto the color image sensor structure 100. The light 902 may be reflected off external object(s) and / or an external scene. The light 902 may propagate in the direction of the z-axis. For simplicity, electrode layers 116 and the flexible encapsulation layer 102 of the color image sensor structure 100 are not shown in FIG. 9.

[0101] The color image sensor structure 100 may receive the light 902. The array of pixel elements 104a in the multilayer stacked structure 112a may absorb a portion (e.g., a first light portion) of the light 902 in the wavelengths of blue color light and a remaining light portion 904 may be passed to the next multilayer stacked structure 112b. The first light portion (e.g., the blue color light) may be converted into first electrical signals (e.g., by the electrode elements 110 in the multilayer stacked structure 112a) and transmitted to the CMOS digital circuitry 920. In anexample, each first electrical signal may correspond to a respective one of the pixel elements 104a and the magnitude of the first electrical signal may be representative of (e.g., directly proportional to) the intensity of the detected blue color light.

[0102] Next, the array of pixel elements 104b in the multilayer stacked structure 112b may absorb a portion (e.g., a second portion) of the light portion 904 in the wavelengths of green color light and a remaining light portion 906 may be passed to the next multilayer stacked structure 112c. The second light portion (e.g., the green color light) may be converted into second electrical signals (e.g., by the electrode elements 110 in the multilayer stacked structure 112b) and transmitted to the CMOS digital circuitry 920. In an example, each second electrical signal may correspond to a respective one of the pixel elements 104b and the magnitude of the second electrical signal may be representative of (e.g., directly proportional to) the detected green color light.

[0103] Next, the array of pixel elements 104c in the multilayer stacked structure 112c may absorb a portion (e.g., a third portion) of the light portion 906 in the wavelengths of red color light. The third light portion (e.g., the red color light) may be converted into third electrical signals (e.g., by the electrode elements 110 in the multilayer stacked structure 112c) and transmitted to the CMOS digital circuitry 920. In an example, each third electrical signal may correspond to a respective one of the pixel elements 104c and the magnitude of the third electrical signal may be representative of (e.g., directly proportional to) the detected red color light. The CMOS digital circuitry 920 may generate a digital color image based on the electrical signals received from the multilayer stacked structure 112a, 112b, and 112c.

[0104] While FIG. 9 illustrates the electronic device 900 using the color image sensor structure 100 for color image sensing, an electronic device 900 may generally include the color image sensor structures 100, 300, and / or 400. In contrast to a CMOS color image sensor, the color image sensor structures 100, 300, and / or 400 discussed herein may eliminate the need for an additional color filter and / or micro-lens as in the CMOS color image sensor, thereby allowing for a smaller-sized, thinner, and more compact image sensor.

[0105] Generally, a high-resolution, flexible image sensor structure and / or device (e.g., the image sensor structures 100, 300, and / or 400) may include any suitable number multilayer stacked structures 112, 312, and / or 412 (e.g., 1, 2, 3 or more). Further, the pixel elements 104 in each multilayer stacked structure 112, 312, and / or 412 may be made of a perovskite single crystalmaterial tuned to absorb light of any suitable wavelength range in a visible light spectrum and / or an invisible light spectrum.

[0106] Compared to CMOS image sensors, the high-resolution, flexible color image sensor structures 100, 300, and 400 discussed herein use signal crystal perovskite as the semiconductor material for light-sensing, realize color-filter free color sensing in a tandem device structure, and realize high-density flexible sensor compatible with any non-flat surface. The desirable properties (e.g., high-resolution, flexible, and color sensing) of the image sensor structures 100, 300, and 400 discussed herein are attributed to using a perovskite single crystal wafer to form a pixel array, ensuring the perovskite single crystal material is of high quality. In this way, the image sensor structures 100, 300, and 400 discussed herein can take advantage of the full potential of perovskite material (e.g., including large photo response and tunable bandgap). Additionally, arranging the multilayer stacked structures 112, 312, or 412 in tandem with pixel elements 104 made of different perovskite compositions in each multilayer stacked structure 112, 312, or 412 allows for the realization of a color-filter free image sensor device. Further, using flexible substrates as the support structure for the electrodes (e.g., the electrode elements 110) and the corresponding pixels (e g., the pixel elements 104) allows for a flexible device. Further still, using lithography patterning technology ensures that the creation of the high-density sensor arrays is compatible with current semiconductor fabrication processes.

[0107] FIG. 10 is a flowchart of an example method 1000 of providing a tandem perovskite single crystal, high-resolution, flexible color image sensor structures according to an embodiment of the present disclosure. The method 1000 may use substantially similar mechanisms as discussed above with reference to FIGS. 5, 6A-6C, 7, and / or 8A-8B. As illustrated, FIG. 10 includes a number of enumerated operations, but embodiments of the operations in FIG. 10 may include additional operations before, after, and in between the enumerated operations. In some embodiments, one or more of the enumerated operations may be omitted or performed in a different order.

[0108] At operation 1002, a perovskite single crystal wafer (e.g., the perovskite single crystal wafer 508) is provided. At operation 1004, the perovskite single crystal wafer is transferred onto a first flexible encapsulation layer (e.g., the flexible encapsulation layer 102-1) to form a first structure (e.g., the structure 512). At operation 1006, the perovskite single crystal wafer is patterned to form an array of perovskite single crystal pixel elements (e.g., the perovskite single crystal pixel elements104) using a lithography process. At operation 1008, an array of electrode elements (e.g., the transparent electrode elements 110 and / or 310) is formed on a second flexible encapsulation layer (e.g., the flexible encapsulation layer 102-2) to form a second structure (e.g., the structure 524 or 724). In an embodiment, the electrode elements may include a transparent electrode material including at least one of ITO, TCO, conducting polymers, and / or carbon-based nanomaterials. In an embodiment, each of the first and second flexible encapsulation layers includes a flexible material including at least one of parylene-C, PMMA, polyimide, polyester, silicon rubbers, urethane rubbers, epoxy resins, epoxy-based photoresist, or amorphous fluoropolymer.

[0109] At operation 1010, the first structure is stacked on (a surface of) the second structure such that each individual perovskite single crystal pixel element of the array of perovskite single crystal pixel elements is aligned to a respective pair of adjacent electrode elements of the array of electrode element to form a multilayer stacked structure (e.g., the multilayer stacked structure 112, 312, and / or 412, the image sensor structures 528, 728, and / or 828). In an embodiment, stacking the first structure on (a surface of) the second structure at operation 1010 includes orienting the first structure (e.g., flipping along the z-axis) such that the array of perovskite single crystal pixel elements faces towards the array of electrode element.

[0110] In an embodiment, the method 1000 further includes forming the first flexible encapsulation layer on a first substrate layer (e.g., the carrier substrate layer 502-1) before transferring the perovskite single crystal wafer onto the first flexible encapsulation layer (e.g., as discussed above with reference to the perovskite single crystal array fabrication processes 504, 704, and / or 804). The method 1000 further includes forming the second flexible encapsulation layer on a second substrate layer (e.g., the carrier substrate layer 502-2) before transferring the array of electrode elements onto the second flexible encapsulation layer (e.g., as discussed above with reference to the electrode array fabrication processes 506, 706, and / or 806). In an embodiment, at least one of forming the first flexible encapsulation layer or forming the second flexible encapsulation layer is based on a film deposition technique including CVD or PVD. The method 1000 further includes removing the first and second substrate layers from the multilayer stacked structure.[0U1] In an embodiment, the method 1000 further includes providing a second perovskite single crystal wafer (e.g., the perovskite single crystal wafer 508) and transferring the second perovskite single crystal wafer onto a third flexible encapsulation layer to form a third structure. Themethod 1000 further includes patterning the second perovskite single crystal wafer to form a second array of perovskite single crystal pixel elements using a lithography process. The method 1000 further includes forming a second array of electrode elements on a fourth flexible encapsulation layer to form a fourth structure. The method 1000 further includes stacking the third structure on (a surface of) the fourth structure such that each individual perovskite single crystal pixel element of the second array of perovskite single crystal pixel elements is aligned to a respective pair of adjacent electrode elements of the second array of electrode elements to form a second multilayer stacked structure. The method 1000 further includes stacking the multilayer stacked structure on (a surface of) the second multilayer stacked structure such that the fourth flexible encapsulation layer of the second multilayer stacked structure is adjacent to the first flexible encapsulation layer of the multilayer stacked structure (e.g., as shown in FIG. 6B and / or 6C). In an embodiment, the perovskite single crystal wafer is provided based on a selection of a first perovskite chemical compound to absorb an optical signal in a first wavelength range (e.g., for one of red, blue, or green color light), and the second perovskite single crystal wafer is provided based on a selection of a second perovskite chemical compound to absorb an optical signal in a second wavelength range (e.g., for a different one of red, blue, or green color light) different than the first wavelength range.

[0112] In an embodiment, the method 1000 further includes forming an electrode layer (e.g., the gate electrode layer 402) on the first flexible encapsulation layer before transferring the perovskite single crystal wafer, where the perovskite single crystal wafer is transferred onto the electrode layer at operation 1004. The method 1000 further includes patterning the electrode layer to form a second array of electrode elements (e.g., the gate electrode elements 406), where the electrode layer and the perovskite single crystal wafer are patterned using the same lithography process (e.g., at operation 1006) such that each electrode element in the second array of electrode elements is aligned to (e.g., in contact with) a respective perovskite single crystal pixel element of the array of perovskite single crystal pixel elements (e.g., as discussed above with reference to the method 800).

[0113] In an embodiment, the method 1000 further includes forming an electrode layer (e.g., the gate electrode layer 402) on the first flexible encapsulation layer. The method 1000 further includes forming a dielectric layer (e.g., the gate dielectric layer 404) on the electrode layer before transferring the perovskite single crystal wafer, where the perovskite single crystal wafer is transferred onto the dielectric layer at operation 1004. The method 1000 further includes patterning the electrode layer and the dielectric layer to respectively form a second array of electrode elements (e.g., the gateelectrode elements 406) and an array of dielectric elements (e.g., the dielectric elements 408), where the electrode layer, the dielectric layer, and the perovskite single crystal wafer are patterned using the same lithography process (e.g., at operation 1006) such that each electrode element in the second array of electrode elements is aligned to a respective dielectric element of the array of dielectric elements and a respective perovskite single crystal pixel element of the array of perovskite single crystal pixel elements (e.g., as discussed above with reference to the method 800).

[0114] In an embodiment, an interface layer may be inserted between adjacent functional layers in any of the color image sensor structures 100, 300, and / or 400 to improve charge transport, energy level alignment, device stability, and efficiency. An interface layer may be a thin film (e.g., having a thickness between about 1 nm to 10 nm). In an example, interface layers may be inserted at the interfaces between semiconductor material and electrode layers (e.g., the electrode layers 116, 316, and 416) to optimize performance. More specifically, an interface layer may be disposed between a pixel array layer 114 and an electrode layer 116 in the color image sensor structure 100, between a pixel array layer 114 and an electrode layer 316 in the color image sensor structure 300, and / or between a pixel array layer 114 and an electrode layer 116 in the color image sensor structure 400. An interface layer may generally modify the interface’s electronic properties without impeding electron transport. In some examples, an interface layer may include semiconductor material, such as metal oxides, lithium fluoride (LiF) / Al, LiF / cesium fluoride (CsF), magnesium (Mg) alloy, nitrogen (N), N’-Di(l-naphthyl)-N, N’-diphenyl-(l,l’-biphenyl)-4, 4’-diamine (NPB), and / or Tris(8-hydroxyquinoline) ( Alq3).

[0115] It should also be understood that the steps of the exemplary methods set forth herein are not necessarily required to be performed in the order described, and the order of the steps of such methods should be understood to be merely exemplary. Likewise, additional steps may be included in such methods, and certain steps may be omitted or combined, in methods consistent with various embodiments of the present disclosure.

[0116] While several embodiments have been provided in the present disclosure, it should be understood that the disclosed systems and methods might be embodied in many other specific forms without departing from the spirit or scope of the present disclosure. The present examples are to be considered as illustrative and not restrictive, and the intention is not to be limited to the details given herein. For example, the various elements or components may be combined or integrated in another system or certain features may be omitted, or not implemented.

[0117] In addition, techniques, systems, subsystems, and methods described and illustrated in the various embodiments as discrete or separate may be combined or integrated with other systems, modules, techniques, or methods without departing from the scope of the present disclosure. Other items shown or discussed as coupled or directly coupled or communicating with each other may be indirectly coupled or communicating through some interface, device, or intermediate component whether electrically, mechanically, or otherwise. Other examples of changes, substitutions, and alterations are ascertainable by one skilled in the art and could be made without departing from the spirit and scope disclosed herein.

Claims

CLAIMSWhat is claimed is:

1. An integrated circuit (IC) structure comprising: an image sensor structure comprising one or more multilayer stacked structures, each of the multilayer stacked structures comprising: a pixel array layer comprising a plurality of pixel elements, each comprising a perovskite single crystal material; an electrode layer adjacent to the pixel array layer, the electrode layer comprising a plurality of electrode elements, wherein each pair of adjacent ones of the plurality of electrode elements corresponds to a respective one of the plurality of pixel elements; a first flexible encapsulation layer, wherein the pixel array layer is between the first flexible encapsulation layer and the electrode layer; and a second flexible encapsulation layer, wherein the electrode layer is disposed between the second flexible encapsulation layer and the pixel array layer.

2. The IC structure of claim 1, wherein the plurality of pixel elements are formed from a perovskite single crystal wafer.

3. The IC structure of any of claims 1-2, wherein each of the first flexible encapsulation layer and the second flexible encapsulation layer comprises a flexible material comprising at least one of parylene-C, polymethyl methacrylate (PMMA), polyimide, polyester, silicon rubbers, urethane rubbers, epoxy resins, epoxy-based photoresist, or amorphous fluoropolymer.

4. The IC structure of any of claims 1-3, wherein a first pixel element and a second pixel element of the plurality of pixel elements in the pixel array layer have the same dimensions.

5. The IC structure of any of claims 1-4, wherein at least one of a width or a length of an individual pixel element of the plurality of pixel elements is less than 25 micrometers (pm).

6. The IC structure of any of claims 1-5, wherein a thickness of an individual pixel element of the plurality of pixel elements is between 0.1 micrometers (pm) and 2 pm.

7. The IC structure of any of claims 1-6, wherein the plurality of pixel elements are uniformly spaced from one another.

8. The IC structure of any of claims 1-7, wherein a pitch between adjacent pixel elements of the plurality of pixel elements is between 0.3 micrometers (pm) and 20 pm.

9. The IC structure of any of claims 1-8, wherein: the perovskite single crystal material in an individual pixel element of the plurality of pixel elements comprises a chemical compound represented by a chemical formula: ABX3,A in the chemical formula comprises at least one of methylammonium ion (MA+), formamidinium cation (FA+), caesium ion (Cs+), calcium ion (Ca2+), or strontium ion (Sr2+),B in the chemical formula comprises at least one of lead (II) ion (Pb2+), tin (II) ion (Sn2+), titanium(IV) cation (Ti41), niobium(V) ion (Nb51), or manganese (IV) cation (Mn41), andC in the chemical formula comprises at least one of oxygen (O2), fluoride ion (F‘), chloride ion (C1‘), bromide ion (Br ), or iodide ion (T).

10. The IC structure any of claims 1-9, wherein: the one or more multilayer stacked structures comprise a first multilayer stacked structure and a second multilayer stacked structure, and the second flexible encapsulation layer of the first multilayer stacked structure is adjacent to the first flexible encapsulation layer of the second multilayer stacked structure.

11. The IC structure of claim 10, wherein each of the plurality of pixel elements in the second multilayer stacked structure is aligned to a respective one of the plurality of pixel elements in the second multilayer stacked structure.

12. The IC structure any of claims 10-11, wherein: the perovskite single crystal material in the plurality of pixel elements in the first multilayer stacked structure is formed from a first perovskite chemical compound that absorbs an optical signal in a first wavelength range, andthe perovskite single crystal material in the plurality of pixel elements in the second multilayer stacked structure is formed from a second perovskite chemical compound that absorbs an optical signal in a second wavelength range different than the first wavelength range.

13. The IC structure of any of claims 1-12, wherein a first electrode element and a second, adjacent electrode element of the plurality of electrode elements corresponding to an individual pixel element of the plurality of pixel elements comprise the same semiconductor material.

14. The IC structure of any of claims 1-12, wherein a first electrode element and a second, adjacent electrode element of the plurality of electrode elements corresponding to an individual pixel element of the plurality of pixel elements comprise different semiconductor materials.

15. The IC structure of any of claims 1-14, wherein an individual multilayer stacked structure of the one or more multilayer stacked structures further comprises: a second electrode layer between the pixel array layer and the first flexible encapsulation layer, the second electrode layer comprising a plurality of second electrode elements, each corresponds to a respective one of the plurality of pixel elements.

16. The IC structure of claim 15, wherein the individual multilayer stacked structure further comprises: a dielectric layer between the pixel array layer and the second electrode layer, the second electrode layer comprising a plurality of dielectric elements, each disposed between a respective one of the plurality of second electrode elements and a respective one of the plurality of pixel elements.

17. The IC structure of any of claims 1-16, wherein the plurality of electrode elements comprise a transparent electrode material comprising at least one of an indium tin oxide (ITO) or a transparent conductive oxide (TCO), conducting polymers, or carbon-based nanomaterials.

18. An electronic device comprising: a tandem color image sensor structure comprising a plurality of multilayer structures stacked along a first direction, wherein:each of the plurality of multilayer structures comprises a first encapsulation layer, a pixel array layer, an electrode layer, a second encapsulation layer stacked in order along the first direction, the pixel array layer comprising an array of pixel elements, each comprising a perovskite single crystal material, and the electrode layer comprising an array of electrode elements, wherein each pair of adjacent electrode elements of the array of electrode elements is coupled to a respective pixel element of the array of pixel elements; and a lens to direct an optical signal to the tandem color image sensor structure.

19. The electronic device of claim 18, wherein the perovskite single crystal material in the array of pixel elements in a first multilayer structure of the plurality of multilayer structures and the perovskite single crystal material in the array of pixel elements in a second multilayer structure of the plurality of multilayer structures absorb optical signals of different light colors.

20. The electronic device of any of claims 18-19, wherein: the array of pixel elements in a first multilayer structure of the plurality of multilayer structures absorbs blue color light, the array of pixel elements in a second multilayer structure of the plurality of multilayer structures absorbs green color light, the array of pixel elements in a third multilayer structure of the plurality of multilayer structures absorbs red color light, and the second multilayer structure is between the first multilayer structure and the third multilayer structure.

21. The electronic device of any of claims 18-20, wherein each of the first encapsulation layer and the second encapsulation layer comprises a flexible material comprising at least one of parylene- C, polymethyl methacrylate (PMMA), polyimide, polyester, silicon rubbers, urethane rubbers, epoxy resins, epoxy-based photoresist, or amorphous fluoropolymer.

22. The electronic device of any of claims 18-21, wherein each individual pixel element of the array of pixel elements in a first multilayer structure of the plurality of multilayer structures is aligned to a respective individual pixel element of the array of pixel elements in a second multilayer structure of the plurality of multilayer structures.

23. The electronic device of any of claims 18-22, wherein at least a first and a second pixel elements in the array of perovskite single crystal pixel elements have the same dimensions.

24. The electronic device of any of claims 18-23, wherein the pixel elements in the array of pixel elements in an individual multilayer structure of the plurality of multilayer structures are uniformly spaced from one another.

25. The electronic device of any of claims 18-24, wherein a first electrode element and a second, adjacent electrode element of the array of electrode elements coupled to an individual pixel element of the array of pixel elements comprise the same semiconductor material.

26. The electronic device of any of claims 18-24, wherein a first electrode element and a second, adjacent electrode element of the array of electrode elements coupled to an individual pixel element of the array of pixel elements comprise different semiconductor materials.

27. The electronic device of any of claims 18-26, wherein an individual multilayer structure of the plurality of multilayer structures further comprises: a second electrode layer between the pixel array layer and the first encapsulation layer, the second electrode layer comprising a plurality of second electrode elements, each coupled to a respective pixel element of the array of pixel elements.

28. The electronic device of claim 27, wherein the individual multilayer structure further comprises: a dielectric layer between the pixel array layer and the second electrode layer, the dielectric layer comprising a plurality of dielectric elements, each disposed between a respective one of the plurality of second electrode elements and a respective pixel element of the array of pixel elements.

29. A method of fabricating a perovskite single crystal image sensor, the method comprising: providing a perovskite single crystal wafer; transferring the perovskite single crystal wafer onto a first flexible encapsulation layer to form a first structure; patterning the perovskite single crystal wafer to form an array of perovskite single crystal pixel elements using a lithography process; forming an array of electrode elements on a second flexible encapsulation layer to form a second structure; and stacking the first structure on the second structure such that each individual perovskite single crystal pixel element of the array of perovskite single crystal pixel elements is aligned to a respective pair of adjacent electrode elements of the array of electrode element to form a multilayer stacked structure.

30. The method of claim 29, wherein each of the first and second flexible encapsulation layers comprises a flexible material comprising at least one of parylene-C, polymethyl methacrylate (PMMA), polyimide, polyester, silicon rubbers, urethane rubbers, epoxy resins, epoxy-based photoresist, or amorphous fluoropolymer.

31. The method of any of claims 29-30, wherein the stacking the first structure on the second structure comprises orienting the first structure such that the array of perovskite single crystal pixel elements faces towards the array of electrode elements.

32. The method of any of claims 29-31, further comprising: forming the first flexible encapsulation layer on a first substrate layer before transferring the perovskite single crystal wafer onto the first flexible encapsulation layer; forming the second flexible encapsulation layer on a second substrate layer before transferring the array of electrode elements onto the second flexible encapsulation layer; and. removing the first and second substrate layers from the multilayer stacked structure.

33. The method of any of claims 29-32, wherein at least one of the forming the first flexible encapsulation layer or the forming the second flexible encapsulation layer is based on a film deposition technique including at least one of chemical vaporization deposition (CVD) or physical vapor deposition (PVD) process.

34. The method of any of claims 29-33, further comprising: providing a second perovskite single crystal wafer; transferring the second perovskite single crystal wafer onto a third flexible encapsulation layer to form a third structure; patterning the second perovskite single crystal wafer to form a second array of perovskite single crystal pixel elements using a lithography process; forming a second array of electrode elements on a fourth flexible encapsulation layer to form a fourth structure; stacking the third structure on the fourth structure such that each individual perovskite single crystal pixel element of the second array of perovskite single crystal pixel elements is aligned to a respective pair of adjacent electrode elements of the second array of electrode elements to form a second multilayer stacked structure; and stacking the multilayer stacked structure on the second multilayer stacked structure such that the fourth flexible encapsulation layer of the second multilayer stacked structure is adjacent to the first flexible encapsulation layer of the multilayer stacked structure.

35. The method of claim 34, wherein: the providing the perovskite single crystal wafer is based on a selection of a first perovskite chemical compound to absorb an optical signal in a first wavelength range, and the providing the second perovskite single crystal wafer is based on a selection of a second perovskite chemical compound to absorb an optical signal in a second wavelength range different than the first wavelength range.

36. The method of any of claims 29-35, further comprising:forming an electrode layer on the first flexible encapsulation layer before transferring the perovskite single crystal wafer, wherein the perovskite single crystal wafer is transferred onto the electrode layer; and patterning the electrode layer to form a second array of electrode elements, wherein the electrode layer and the perovskite single crystal wafer are patterned using the same lithography process such that each electrode element in the second array of electrode elements is aligned to a respective perovskite single crystal pixel element of the array of perovskite single crystal pixel elements.

37. The method of any of claims 29-35, further comprising: forming an electrode layer on the first flexible encapsulation layer; forming a dielectric layer on the electrode layer before transferring the perovskite single crystal wafer, wherein the perovskite single crystal wafer is transferred onto the dielectric layer; and patterning the electrode layer and the dielectric layer to respectively form a second array of electrode elements and an array of dielectric elements, wherein the electrode layer, the dielectric layer, and the perovskite single crystal wafer are patterned using the same lithography process such that each electrode element in the second array of electrode elements is aligned to a respective dielectric element of the array of dielectric elements and a respective perovskite single crystal pixel element of the array of perovskite single crystal pixel elements.

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