Sensors and electronics

Abstract

Sensors and electronic devices are provided. A sensor includes an anode and a cathode and a near-infrared photoelectric conversion layer between the anode and the cathode. The near-infrared photoelectric conversion layer is configured to absorb light of at least a portion of a near-infrared wavelength spectrum and convert the absorbed light into an electrical signal. The near-infrared photoelectric conversion layer includes a first material having a maximum absorption wavelength in the near-infrared wavelength spectrum and a second material forming a pn junction with the first material and having an energy band gap wider than an energy band gap of the first material. The first material is included in the near-infrared photoelectric conversion layer in a smaller amount than the second material.

Description

TECHNICAL FIELD

[0001] Disclosed are a sensor and an electronic device. BACKGROUND

[0002] An imaging device is used in a digital camera, a camcorder, or the like, to capture an image and store it as an electrical signal. The imaging device includes an image sensor for separating incident light according to wavelength and converting each component into an electrical signal.

[0003] Recently, a photodiode in a near-infrared wavelength spectrum has been researched to improve the sensitivity of a sensor in a low-illumination environment or used as a biometric recognition device or an authentication device. SUMMARY

[0004] Some example embodiments provide a sensor exhibiting improved electrical characteristics.

[0005] Some example embodiments provide an electronic device including the sensor.

[0006] According to some example embodiments, a sensor can include an anode and a cathode and a near-infrared photoelectric conversion layer between the anode and the cathode. The near-infrared photoelectric conversion layer can be configured to absorb light of at least a portion of a near-infrared wavelength spectrum and convert the absorbed light into an electrical signal. The near-infrared photoelectric conversion layer can include a first amount of a first material having a maximum absorption wavelength in the near-infrared wavelength spectrum and a second amount of a second material forming a pn junction with the first material. The second material can have an energy band gap wider than that of the first material. The first amount can be less than the second amount.

[0007] A difference between a highest occupied molecular orbital (HOMO) energy level of the first material and a work function of the cathode can be less than about 1.0 eV.

[0008] A difference between a highest occupied molecular orbital (HOMO) energy level of the second material and a HOMO energy level of the first material can be greater than or equal to about 1.0 eV.

[0009] A difference between a highest occupied molecular orbital (HOMO) energy level of the second material and a work function of the cathode can be greater than or equal to about 1.5 eV.

[0010] An energy band gap of the second material can be wider than that of the first material by about 0.5 eV to about 2.0 eV.

[0011] A maximum absorption wavelength of the second material can not be within the near-infrared wavelength spectrum.

[0012] A composition ratio of the first material with respect to the second material can be about 0.10 to about 0.90.

[0013] The composition ratio of the first material to the second material can be about 0.10 to about 0.50.

[0014] The near-infrared photoelectric conversion layer can include a mixed layer including a mixture of the first material and the second material.

[0015] The near-infrared photoelectric conversion layer can have a maximum absorption wavelength within about 750 nm to about 1500 nm.

[0016] The sensor can further include a charge auxiliary layer between the near-infrared photoelectric conversion layer and the cathode.

[0017] A difference between a highest occupied molecular orbital (HOMO) energy level of the charge auxiliary layer and a work function of the cathode can be greater than or equal to about 1.5 eV.

[0018] The sensor can further include a charge auxiliary layer between the near-infrared photoelectric conversion layer and the anode.

[0019] A difference between a lowest unoccupied molecular orbital (LUMO) energy level of the charge auxiliary layer and a work function of the anode can be greater than or equal to about 1.5 eV.

[0020] The sensor can further include a semiconductor substrate, wherein the cathode, the anode, and the near-infrared photoelectric conversion layer are stacked on the semiconductor substrate.

[0021] The sensor can further include a visible light sensor configured to detect light in a visible wavelength spectrum.

[0022] The visible light sensor can include a blue sensor configured to sense light in a blue wavelength spectrum, a green sensor configured to sense light in a green wavelength spectrum, and a red sensor configured to sense light in a red wavelength spectrum. The blue sensor, the green sensor, and the red sensor can be integrated in the semiconductor substrate.

[0023] The visible light sensor can include a blue sensor configured to sense light in a blue wavelength spectrum, a green sensor configured to sense light in a green wavelength spectrum, and a red sensor configured to sense light in a red wavelength spectrum. Two of the blue sensor, the green sensor, and the red sensor can be photodiodes integrated in the semiconductor substrate, and a remaining one of the blue sensor, the green sensor, and the red sensor can be a photoelectric conversion device on the semiconductor substrate.

[0024] The photoelectric conversion device can include a visible light photoelectric conversion layer between the pair of electrodes, the visible light photoelectric conversion layer configured to absorb visible light of one of a blue wavelength spectrum, a green wavelength spectrum, and a red wavelength spectrum to convert the absorbed visible light into a visible light electric signal.

[0025] The visible light sensor can include a blue sensor configured to sense light in a blue wavelength spectrum, a green sensor configured to sense light in a green wavelength spectrum, and a red sensor configured to sense light in a red wavelength spectrum. Each of the blue sensor, the green sensor, and the red sensor can be a photoelectric conversion device.

[0026] The blue sensor can include a blue photoelectric conversion layer configured to absorb first light in a blue wavelength spectrum and convert the first light into a first electrical signal. The green sensor can include a green photoelectric conversion layer configured to absorb second light in a green wavelength spectrum and convert the second light into a second electrical signal. The red sensor can include a red photoelectric conversion layer configured to absorb third light in a red wavelength spectrum and convert the third light into a third electrical signal.

[0027] An electronic device can include the sensor.

[0028] According to some example embodiments, a sensor can include an anode and a cathode and a near-infrared photoelectric conversion layer between the anode and the cathode. The near-infrared photoelectric conversion layer can be configured to absorb light of at least a portion of a near-infrared wavelength spectrum and convert the absorbed light into an electrical signal. The near-infrared photoelectric conversion layer can include a first amount of a first material having a maximum absorption wavelength in the near-infrared wavelength spectrum and a second amount of a second material forming a pn junction with the first material. The second material can have a maximum absorption wavelength not in the near-infrared wavelength spectrum. The first amount can be less than the second amount.

[0029] The second material can have an energy band gap wider than that of the first material.

[0030] A difference between a highest occupied molecular orbital (HOMO) energy level of the first material and a work function of the cathode can be less than about 1.0 eV.

[0031] A difference between a highest occupied molecular orbital (HOMO) energy level of the second material and a HOMO energy level of the first material can be greater than or equal to about 1.0 eV.

[0032] A difference between a highest occupied molecular orbital (HOMO) energy level of the second material and a work function of the cathode can be greater than or equal to about 1.5 eV.

[0033] The energy band gap of the second material can be wider than that of the first material by about 0.5 eV to about 2.0 eV.

[0034] A composition ratio of the first material with respect to the second material can be about 0.10 to about 0.90.

[0035] The composition ratio of the first material with respect to the second material can be about 0.10 to about 0.50.

[0036] The near-infrared photoelectric conversion layer can include a mixed layer including a mixture of the first material and the second material.

[0037] The maximum absorption wavelength of the near-infrared photoelectric conversion layer can be within about 750 nm to about 1500 nm.

[0038] The electrical characteristics of the sensor can be improved. BRIEF DESCRIPTION OF DRAWINGS

[0039] Figure 1 is a cross-sectional view illustrating an example of a near-infrared light sensor according to some example embodiments,

[0040] Figure 2 is a cross-sectional view illustrating another example of a near-infrared light sensor according to some example embodiments,

[0041] Figure 3 is a cross-sectional view illustrating an example of a sensor according to some example embodiments,

[0042] Figure 4 is a cross-sectional view illustrating an example of a sensor according to some example embodiments,

[0043] Figure 5 is a cross-sectional view illustrating an example of a sensor according to some example embodiments,

[0044] Figure 6 is a cross-sectional view illustrating an example of a sensor according to some example embodiments,

[0045] Figure 7 is a schematic cross-sectional view illustrating an example of a sensor according to some example embodiments,

[0046] Figure 8 is a schematic cross-sectional view illustrating an example of a sensor according to some example embodiments,

[0047] Figure 9 is a perspective view illustrating an example of a sensor according to some example embodiments,

[0048] Figure 10 is a perspective view illustrating Figure 9 is a schematic cross-sectional view illustrating an example of a sensor,

[0049] Figure 11 is a perspective view illustrating an example of a sensor according to some example embodiments,

[0050] Figure 12 is a perspective view illustrating Figure 11a schematic cross-sectional view of an example of the sensor shown, and

[0051] Figure 13 is a schematic diagram of an electronic device according to some example embodiments. DETAILED DESCRIPTION

[0052] Hereinafter, example embodiments of the inventive concept will be described in detail so that those skilled in the art will understand the example embodiments of the inventive concept. However, the present disclosure can be embodied in many different forms and should not be construed as being limited to the example embodiments set forth herein.

[0053] In the drawings, the thicknesses of layers, films, panels, regions, etc., are exaggerated for clarity. Like reference numerals can represent like elements throughout the description. It will be understood that when an element such as a layer, film, region or substrate is referred to as being "on" another element, it can be directly on the other element or intervening elements can also be present. In contrast, when an element is referred to as being "directly on" another element, there are no intervening elements present.

[0054] Hereinafter, a work function, a highest occupied molecular orbital (HOMO) level or a lowest unoccupied molecular orbital (LUMO) level is expressed as an absolute value from a vacuum level. Also, when a work function, a HOMO level or a LUMO level is referred to as deep, high or large, it can have a large absolute value based on "0 eV" of the vacuum level, and when a work function, a HOMO level or a LUMO level is referred to as shallow, low or small, it can have a small absolute value based on "0 eV" of the vacuum level.

[0055] Hereinafter, a band gap refers to an absolute value of a difference between a HOMO level and a LUMO level, and a wide band gap means a large absolute value of a difference between a HOMO level and a LUMO level.

[0056] Hereinafter, a sensor according to some example embodiments is described.

[0057] A sensor according to some example embodiments includes a sensor configured to sense light in a near-infrared wavelength spectrum (hereinafter referred to as a "near-infrared light sensor"). The near-infrared light sensor is a sensor configured to sense light in at least a portion of the near-infrared wavelength spectrum. For example, the near-infrared light sensor can be configured to selectively absorb light at at least a portion of the near-infrared wavelength spectrum and convert the light into an electrical signal. The near-infrared light sensor can exhibit an absorption spectrum having a maximum absorption wavelength in the near-infrared wavelength spectrum. The near-infrared wavelength spectrum may, for example, be in a range of greater than about 700 nm and less than or equal to about 3000 nm, such as about 750 nm to about 3000 nm, about 750 nm to about 2000 nm, about 750 nm to about 1800 nm, about 750 nm to about 1500 nm, about 750 nm to about 1300 nm, about 750 nm to about 1200 nm, about 750 nm to about 1100 nm, or about 750 nm to about 1000 nm.

[0058] When the term "about" or "substantially" is used in the present description in connection with a numerical value, it is intended that the associated numerical value include a tolerance of ±10% around the recited numerical value. When a range is specified, the range includes all values therebetween, such as in increments of 0.1%.

[0059] The near-infrared light sensors can each independently include a light-sensitive device such as a photodiode or a photoelectric conversion device.

[0060] Figure 1 is a cross-sectional view showing an example of a near-infrared light sensor according to some example embodiments.

[0061] Referring to Figure 1 The near-infrared light sensor 100 (also referred to herein as a "sensor") according to some example embodiments includes a first electrode 110 and a second electrode 120 facing each other (e.g., opposite each other) and a near-infrared photoelectric conversion layer 130 between the first electrode 110 and the second electrode 120.

[0062] A substrate (not shown) can be provided on one side of the first electrode 110 (e.g., directly or indirectly on the surface 110a) or on one side of the second electrode 120 (e.g., directly or indirectly on the surface 120a). The substrate may, for example, be made of an inorganic material such as glass, an organic material such as polycarbonate, polymethyl methacrylate, polyethylene terephthalate, polyethylene naphthalate, polyamide, polyethersulfone, or a combination thereof, or a silicon wafer (e.g., can at least partially include an inorganic material such as glass, an organic material such as polycarbonate, polymethyl methacrylate, polyethylene terephthalate, polyethylene naphthalate, polyamide, polyethersulfone, or a combination thereof, or a silicon wafer). The substrate can be omitted.

[0063] One of the first electrode 110 and the second electrode 120 is an anode, and the other is a cathode. For example, the first electrode 110 can be an anode, and the second electrode 120 can be a cathode. For example, the first electrode 110 can be a cathode, and the second electrode 120 can be an anode.

[0064] At least one of the first electrode 110 and the second electrode 120 can be a transparent electrode. The transparent electrode can have a high transmittance greater than or equal to about 80%, greater than or equal to about 85%, greater than or equal to about 88%, or greater than or equal to about 90%, and can include, for example, at least one of an oxide conductor, a carbon conductor, and a metal thin film. The oxide conductor can be, for example, one or more selected from indium tin oxide (ITO), indium zinc oxide (IZO), zinc tin oxide (ZTO), aluminum tin oxide (AlTO), and aluminum zinc oxide (AZO). The carbon conductor can be one or more selected from graphene and carbon nanostructures. The metal thin film can be formed, for example, in a thin thickness of several nanometers to several tens of nanometers in thickness, or can be a single layer or a multi-layer of a metal thin film formed in a thin thickness of several nanometers to several tens of nanometers in thickness and doped with a metal oxide.

[0065] One of the first electrode 110 and the second electrode 120 can be a reflective electrode. The reflective electrode can have a low transmittance of, for example, less than about 10% or less than or equal to about 5%. The reflective electrode can include a reflective conductor such as a metal, and can include, for example, aluminum (Al), silver (Ag), gold (Au), or an alloy thereof.

[0066] For example, the first electrode 110 and the second electrode 120 can each be a transparent electrode. For example, the first electrode 110 can be a reflective electrode, and the second electrode 120 can be a transparent electrode. For example, the first electrode 110 can be a transparent electrode, and the second electrode 120 can be a reflective electrode.

[0067] The near-infrared photoelectric conversion layer 130 can be configured to absorb light in at least a portion of the near-infrared wavelength spectrum and convert the absorbed light into an electrical signal. The absorption spectrum of the near-infrared photoelectric conversion layer 130 can for example be expressed in a wavelength spectrum ranging from greater than about 700 nm and less than or equal to about 3000 nm, for example from about 750 nm to about 3000 nm, from about 750 nm to about 2000 nm, from about 750 nm to about 1800 nm, from about 750 nm to about 1500 nm, from about 750 nm to about 1300 nm, from about 750 nm to about 1200 nm, from about 750 nm to about 1100 nm, or from about 750 nm to about 1000 nm. The maximum absorption wavelength of the near-infrared photoelectric conversion layer 130 can for example be expressed in a wavelength spectrum ranging from greater than about 700 nm and less than or equal to about 3000 nm, for example from about 750 nm to about 3000 nm, from about 750 nm to about 2000 nm, from about 750 nm to about 1800 nm, from about 750 nm to about 1500 nm, from about 750 nm to about 1300 nm, from about 750 nm to about 1200 nm, from about 750 nm to about 1100 nm, or from about 750 nm to about 1000 nm.

[0068] The near-infrared photoelectric conversion layer 130 can include at least one first material and at least one second material that collectively form a pn junction. One of the first material and the second material can be a p-type semiconductor and the other can be an n-type semiconductor. For example, the first material can be a p-type semiconductor and the second material can be an n-type semiconductor. For example, the first material can be an n-type semiconductor and the second material can be a p-type semiconductor.

[0069] The first material and the second material can each be an organic material, an inorganic material, or an organic / inorganic material, for example at least one of the first material and the second material can be an organic material. At least one of the first material and the second material can be a light-absorbing material, for example the first material and the second material can each be a light-absorbing material.

[0070] The first material and the second material can have different light-absorbing properties. The absorption spectrum of the first material and the absorption spectrum of the second material can be different. The maximum absorption wavelength of the first material and the maximum absorption wavelength of the second material can be different. For example, the absorption spectrum of the first material can be expressed in a longer wavelength spectrum than the absorption spectrum of the second material, and the maximum absorption wavelength of the first material can be a longer wavelength than the maximum absorption wavelength of the second material.

[0071] For example, the first material can be a near-infrared absorbing material configured to primarily absorb light in a near-infrared wavelength spectrum, and the first material can have a maximum absorption wavelength within the near-infrared wavelength spectrum. The maximum absorption wavelength of the first material may, for example, be in a range of greater than about 700 nm and less than or equal to about 3000 nm, such as about 750 nm to about 3000 nm, about 750 nm to about 2000 nm, about 750 nm to about 1800 nm, about 750 nm to about 1500 nm, about 750 nm to about 1300 nm, about 750 nm to about 1200 nm, about 750 nm to about 1100 nm, or about 750 nm to about 1000 nm.

[0072] The second material can not be a near-infrared absorbing material configured to primarily absorb light in a near-infrared wavelength spectrum, and the second material can not have a maximum absorption wavelength within the near-infrared wavelength spectrum. For example, the second material can be a visible absorbing material configured to primarily absorb light in a visible wavelength spectrum, but not in a near-infrared wavelength spectrum, and the second material can have a maximum absorption wavelength within the visible wavelength spectrum, but not within the near-infrared wavelength spectrum. The visible wavelength spectrum can be in a range of greater than or equal to 380 nm and less than 700 nm, such as about 380 nm to about 680 nm. In another example, the second material can be an ultraviolet absorbing material configured to primarily absorb light in an ultraviolet wavelength spectrum, but not in a near-infrared wavelength spectrum, and the second material can have a maximum absorption wavelength within the ultraviolet wavelength spectrum, but not within the near-infrared wavelength spectrum. The ultraviolet wavelength spectrum can be greater than or equal to 10 nm and less than 400 nm. It will be understood that, in some example embodiments, the second material can be a near-infrared absorbing material configured to primarily absorb light in a near-infrared wavelength spectrum, and the second material can have a maximum absorption wavelength within the near-infrared wavelength spectrum.

[0073] The first material and the second material can have different electrical properties. For example, the energy diagram of the first material and the energy diagram of the second material can be different.

[0074] For example, the first material can have a relatively shallow HOMO energy level. For example, the first material can have a HOMO energy level of about 4.0 eV to about 5.5 eV. The HOMO energy level of the second material can be deeper than the HOMO energy level of the first material. For example, the difference between the HOMO energy level of the second material and the HOMO energy level of the first material can be greater than or equal to about 0.8 eV, greater than or equal to about 0.9 eV, or greater than or equal to about 1.0 eV, such as about 0.8 eV to about 2.0 eV, about 0.8 eV to about 1.8 eV, about 0.8 eV to about 1.7 eV, about 0.8 eV to about 1.5 eV, about 0.9 eV to about 2.0 eV, about 0.9 eV to about 1.8 eV, about 0.9 eV to about 1.7 eV, about 0.9 eV to about 1.5 eV, about 1.0 eV to about 2.0 eV, about 1.0 eV to about 1.8 eV, about 1.0 eV to about 1.7 eV, or about 1.0 eV to about 1.5 eV. For example, the HOMO energy level of the second material can be about 5.6 eV to about 7.0 eV.

[0075] For example, the LUMO energy level of the first material can be about 3.0 eV to about 4.5 eV. The LUMO energy level of the second material can be deeper or shallower than the LUMO energy level of the first material, and the LUMO energy level of the second material can be about 3.6 eV to about 5.0 eV.

[0076] For example, the energy band gap of the first material can be about 0.5 eV to about 1.5 eV. The energy band gap of the second material can be wider than the energy band gap of the first material, although example embodiments are not limited thereto, as in some example embodiments, the energy band gap of the second material can not be wider than the energy band gap of the first material. For example, the energy band gap of the second material can be greater than or equal to about 0.3 eV, greater than or equal to about 0.5 eV, greater than or equal to about 0.7 eV, greater than or equal to about 0.8 eV, or greater than or equal to about 1.0 eV, wider than the energy band gap of the first material. For example, the energy band gap of the second material can be about 0.3 eV to about 2.0 eV, about 0.5 eV to about 2.0 eV, about 0.7 eV to about 2.0 eV, about 0.8 eV to about 2.0 eV, or about 1.0 eV to about 2.0 eV, wider than the energy band gap of the first material. For example, the energy band gap of the second material can be about 0.8 eV to about 2.4 eV.

[0077] The near-infrared photoelectric conversion layer 130 can include a mixed layer in which the first material and the second material are mixed in a bulk heterojunction form (e.g., the near-infrared photoelectric conversion layer 130 can include a bulk heterojunction mixture of the first material and the second material), such that the pn junction includes the mixed layer of the first material and the second material. In some example embodiments, the near-infrared photoelectric conversion layer 130 can include a mixture of the first material and the second material defining the pn junction, including a mixture comprising: a bulk heterojunction of the first material and the second material, a gradual heterojunction of the first material and the second material, a continuous junction of the first material and the second material, a discrete heterojunction of the first material and the second material, a homogenous mixture of the first material and the second material, any combination thereof, or the like. The mixed layer can include the first material and the second material in a particular (or alternatively predetermined) composition ratio, where the composition ratio (sometimes referred to herein as a ratio of the first material to the second material) can be defined as a ratio of a volume or thickness of the first material to a volume or thickness of the second material. The composition ratio can be defined as a ratio of an amount (e.g., a “first amount”) of the first material to an amount (e.g., a “second amount”) of the second material.

[0078] As described herein, an “amount” of the first material and / or the second material can refer to a volume, a thickness, and / or a mass of the respective material being described.

[0079] For example, the near-infrared photoelectric conversion layer 130 can include a first amount of the first material and a second amount of the second material, where the first amount is less than the second amount, and a composition ratio of the first material to the second material in the near-infrared photoelectric conversion layer 130 can be about 0.10 to about 0.90. Within this range, the composition ratio of the first material to the second material can be about 0.10 to about 0.80, about 0.10 to about 0.70, about 0.10 to about 0.50, or about 0.10 to about 0.30.

[0080] As such, by controlling the composition ratio of the first material and the second material in the near-infrared photoelectric conversion layer 130, a dark current of the near-infrared light sensor 100 can be effectively reduced.

[0081] Specifically, in the near-infrared light sensor 100, light enters through the first electrode 110 or the second electrode 120, and the near-infrared photoelectric conversion layer 130 is configured to absorb light of a particular (or alternatively predetermined) wavelength spectrum, thereby generating excitons therein. The excitons separate into a hole and an electron in the near-infrared photoelectric conversion layer 130, the separated hole moves to an anode (which is one of the first electrode 110 and the second electrode 120) and the separated electron moves to a cathode (which is the other of the first electrode 110 and the second electrode 120), thereby causing a current to flow.

[0082] Here, because the first material of the near-infrared photoelectric conversion layer 130 has a relatively shallow HOMO energy level as described above, the energy barrier with the cathode is low, which can unintentionally increase the dark current under a reverse bias. For example, given that the work function of the cathode is generally about 4.0 eV to 4.7 eV, the energy barrier between the first material and the cathode, i.e., the difference between the HOMO energy level of the first material and the work function of the cathode, is, for example, less than about 1.0 eV, less than about 0.8 eV, less than about 0.7 eV, less than about 0.6 eV, or less than about 0.5 eV, such that charges such as holes move from the cathode to the near-infrared photoelectric conversion layer 130 under a reverse bias, thus possibly increasing the adverse dark current.

[0083] In contrast, because the second material of the near-infrared photoelectric conversion layer 130 has a deeper HOMO energy level than the first material as described above, the second material can form a sufficient energy barrier with the cathode, thereby suppressing the dark current under a reverse bias. For example, given that the work function of the cathode is about 4.0 eV to 4.7 eV, the energy barrier between the second material and the cathode, i.e., the difference between the HOMO energy level of the second material and the work function of the cathode, can be relatively large, for example, greater than or equal to about 1.5 eV, greater than or equal to about 1.7 eV, greater than or equal to about 1.8 eV, greater than or equal to about 2.0 eV, about 1.5 eV to about 2.5 eV, about 1.7 eV to about 2.5 eV, about 1.8 eV to about 2.5 eV, or about 2.0 eV to about 2.5 eV, thereby preventing or reducing charges such as holes from moving from the cathode to the near-infrared photoelectric conversion layer 130 under a reverse bias, thus suppressing the dark current.

[0084] Thus, by reducing the composition ratio of the first material relative to the second material in the near-infrared photoelectric conversion layer 130, the dark current of the near-infrared light sensor 100 can be effectively reduced. For example, by controlling the composition ratio of the first material relative to the second material to be, for example, less than about 1, about 0.10 to about 0.90, about 0.10 to about 0.80, about 0.10 to about 0.70, about 0.10 to about 0.50, about 0.10 to about 0.40, about 0.10 to about 0.35, or about 0.10 to about 0.30, the dark current of the near-infrared light sensor 100 can be effectively suppressed. Reiterate that the near-infrared photoelectric conversion layer 130 can include a first amount of the first material and a second amount of the second material forming a pn junction with the first material (e.g., a mixture of the first amount of the first material and the second amount of the second material), where the first amount is less than the second amount, such that the near-infrared photoelectric conversion layer 130 includes a smaller amount of the first material than the second material.

[0085] The near-infrared photoelectric conversion layer 130 can have a thickness in a range of about 100 nm to about 500 nm, for example, about 150 nm to about 500 nm, about 200 nm to about 500 nm, or about 230 nm to about 500 nm.

[0086] Hereinafter, a sensor according to some example embodiments is described.

[0087] Figure 2 is a cross-sectional view showing another example of a near-infrared light sensor according to some example embodiments.

[0088] Referring to Figure 2 As with the foregoing example embodiments, the near-infrared light sensor 100a according to some example embodiments includes a first electrode 110 and a second electrode 120 facing each other and a near-infrared photoelectric conversion layer 130 between the first electrode 110 and the second electrode 120.

[0089] However, in some example embodiments, the near-infrared light sensor 100a according to the present example further includes a charge auxiliary layer 140 and / or 150 between the first electrode 110 and the near-infrared photoelectric conversion layer 130 and / or between the second electrode 120 and the near-infrared photoelectric conversion layer 130. The charge auxiliary layers 140 and 150 can improve the efficiency of the near-infrared light sensor 100a by controlling the mobility of holes and / or electrons separated from the near-infrared photoelectric conversion layer 130.

[0090] For example, when the first electrode 110 is an anode and the second electrode 120 is a cathode, the charge auxiliary layer 140 can be a hole injection layer (HIL) for facilitating hole injection, a hole transport layer (HTL) for facilitating hole transport, and / or an electron blocking layer (EBL) for preventing electron transport, and the charge auxiliary layer 150 can be an electron injection layer (EIL) for facilitating electron injection, an electron transport layer (ETL) for facilitating electron transport, and / or a hole blocking layer (HBL) for preventing hole transport.

[0091] For example, when the first electrode 110 is a cathode and the second electrode 120 is an anode, the charge auxiliary layer 140 can be an electron injection layer (EIL) for facilitating electron injection, an electron transport layer (ETL) for facilitating electron transport, and / or a hole blocking layer (HBL) for preventing hole transport, and the charge auxiliary layer 150 can be a hole injection layer (HIL) for facilitating hole injection, a hole transport layer (HTL) for facilitating hole transport, and / or an electron blocking layer (EBL) for preventing electron transport.

[0092] For example, one of the charge auxiliary layers 140 and 150 can include a first material, and the other of the charge auxiliary layers 140 or 150 can include a second material. In some example embodiments, for example, in a case where the charge auxiliary layer 140 is between the near-infrared photoelectric conversion layer 130 and the first electrode 110 that is a cathode, the charge auxiliary layer 140 can include the second material so that a difference between the HOMO energy level of the charge auxiliary layer 140 and the work function of the cathode can be relatively large, for example, greater than or equal to about 1.5 eV, greater than or equal to about 1.7 eV, greater than or equal to about 1.8 eV, greater than or equal to about 2.0 eV, about 1.5 eV to about 2.5 eV, about 1.7 eV to about 2.5 eV, about 1.8 eV to about 2.5 eV, or about 2.0 eV to about 2.5 eV. In some example embodiments, for example, in a case where the charge auxiliary layer 150 is between the near-infrared photoelectric conversion layer 130 and the second electrode 120 that is an anode, the charge auxiliary layer 150 can include the first material so that a difference between the LUMO energy level of the charge auxiliary layer 150 and the work function of the anode can be relatively large, for example, greater than or equal to about 1.5 eV, greater than or equal to about 1.7 eV, greater than or equal to about 1.8 eV, greater than or equal to about 2.0 eV, about 1.5 eV to about 2.5 eV, about 1.7 eV to about 2.5 eV, about 1.8 eV to about 2.5 eV, or about 2.0 eV to about 2.5 eV.

[0093] Any of the charge auxiliary layers 140 and 150 can be omitted.

[0094] The near-infrared light sensor 100 / 100a can be applied to (for example, included in) various sensors for sensing light in a near-infrared wavelength spectrum, such as a sensor for improving sensitivity in a low-illuminance environment, a sensor for extending a dynamic range of a specific black-and-white contrast, thus improving sensing capability of a long-distance 3-dimensional image, or a biometric sensor. The biometric sensor can be, for example, an iris sensor, a depth sensor, a fingerprint sensor, or a blood vessel distribution sensor, but is not limited thereto. The near-infrared light sensor 100 / 100a can be applied, for example, to a CMOS near-infrared light sensor or a CMOS image sensor.

[0095] Figure 3 is a cross-sectional view illustrating an example of a sensor according to some example embodiments.

[0096] The sensor 300 according to some example embodiments includes a semiconductor substrate 40, an insulating layer (hereinafter also referred to as an upper insulating layer) 80, and a near-infrared light sensor 100.

[0097] The semiconductor substrate 40 can be a silicon substrate and be integrated with a transfer transistor (not shown) and a charge storage portion 55. The charge storage portion 55 can be integrated in each pixel. The charge storage portion 55 is electrically connected to the near-infrared light sensor 100, and information of the charge storage portion 55 can be transferred by the transfer transistor.

[0098] Metal lines (not shown) and pads (not shown) are formed on the semiconductor substrate 40. To reduce signal delay, the metal lines and pads can be made of a metal having a low resistivity, such as aluminum (Al), copper (Cu), silver (Ag), and alloys thereof, but are not limited thereto. However, not limited to the structure, the metal lines and pads can be disposed under the semiconductor substrate 40.

[0099] An insulating layer 80 is formed on the metal lines and pads. The insulating layer 80 can be made of an inorganic insulating material, such as silicon oxide and / or silicon nitride, or a low dielectric constant (low-K) material, such as SiC, SiCOH, SiCO, and SiOF. The insulating layer 80 has a trench 85 that exposes the charge storage portion 55. The trench 85 can be filled with a filler.

[0100] The aforementioned near-infrared light sensor 100 is formed on the insulating layer 80. The near-infrared light sensor 100 includes the first electrode 110, the second electrode 120, and the near-infrared photoelectric conversion layer 130 as described above, and can also optionally include a charge auxiliary layer (not shown). As shown, the first electrode 110, the second electrode 120, and the near-infrared photoelectric conversion layer 130 are stacked on (e.g., over) the semiconductor substrate 40.

[0101] Both the first electrode 110 and the second electrode 120 can be transparent electrodes, and the first electrode 110, the second electrode 120, and the near-infrared photoelectric conversion layer 130 are the same as described above. Light of a near-infrared wavelength spectrum among the light incident from the second electrode 120 can be effectively absorbed by the near-infrared photoelectric conversion layer 130 and then photoelectrically converted. As described above, by controlling the composition ratio of the first material and the second material of the near-infrared photoelectric conversion layer 130, the dark current can be effectively suppressed under reverse bias, thereby enabling the near-infrared light sensor 100 to exhibit excellent photoelectric conversion characteristics.

[0102] In Figure 3 , examples of the near-infrared light sensor 100 including Figure 1 are shown, but are not limited thereto. The near-infrared light sensor 100a including Figure 2 may also be included.

[0103] In some example embodiments, as Figure 3As shown, the separate first electrodes 110 can define separate pixels P1, P2 of the sensor 300, where each pixel includes some or all of a portion of the sensor 300 included within a region having lateral boundaries defined by lateral boundaries of the separate respective first electrodes 110. The separate portions of the near-infrared light sensor 100 in the separate pixels P1, P2 of the sensor 300 can be referred to as separate sub-sensors 100-1, 100-2, where each of the separate sub-sensors 100-1, 100-2 can be defined by a separate near-infrared photoelectric conversion layer 130-1, 130-2 including a separate first electrode 110 and / or near-infrared photoelectric conversion layer 130.

[0104] In some example implementations, as Figure 3 As shown, the separate pixels of the sensor 300 can include separate near-infrared photoelectric conversion layers 130-1 and 130-2 that can be at least partially co-planar with each other and collectively define the near-infrared photoelectric conversion layer 130, such that the separate sub-sensors 100-1, 100-2 in the separate pixels include separate respective near-infrared photoelectric conversion layers 130-1 and 130-2. In some example implementations, each of the separate near-infrared photoelectric conversion layers 130-1 and 130-2 is configured to absorb and photoelectrically convert light of a different near-infrared wavelength spectrum, such that the separate sub-sensors 100-1, 100-2 in the separate pixels are configured to photoelectrically convert different wavelength spectra of near-infrared light. In some example implementations, each of the separate near-infrared photoelectric conversion layers 130-1 and 130-2 includes a first material that is different from (e.g., in material and / or compound composition) a first material of other near-infrared photoelectric conversion layers of the near-infrared photoelectric conversion layers 130-1, 130-2 of the sensor 300 and / or a second material that is different from (e.g., in material and / or compound composition) a second material of other near-infrared photoelectric conversion layers of the near-infrared photoelectric conversion layers 130-1, 130-2 of the sensor 300. In some example implementations, each of the separate near-infrared photoelectric conversion layers 130-1 and 130-2 includes the first material and the second material in different composition ratios.

[0105] A focusing lens (not shown) can be further formed on the near-infrared light sensor 100. The focusing lens can control the direction of incident light and concentrate the light in one area. The focusing lens can have a shape of, for example, a cylinder or a hemisphere, but is not limited thereto.

[0106] Figure 4 is a cross-sectional view showing an example of a sensor according to some example implementations.

[0107] The sensor according to some example embodiments can include a plurality of sensors having different functions. At least one sensor of the plurality of sensors having different functions can be a biometric sensor. The biometric sensor can be, for example, an iris sensor, a depth sensor, a fingerprint sensor, or a blood vessel distribution sensor, but is not limited thereto. For example, one sensor of the plurality of sensors having different functions can be an iris sensor, and another can be a depth sensor.

[0108] For example, the plurality of sensors can include a first infrared light sensor configured to sense light in a near-infrared region including a first wavelength (λ1) and a second infrared light sensor configured to sense infrared light within a near-infrared wavelength spectrum including a second wavelength (λ2).

[0109] The first wavelength (λ1) and the second wavelength (λ2) can be different from each other within, for example, a wavelength spectrum greater than about 700 nm and less than or equal to about 3000 nm. For example, a difference between the first wavelength (λ1) and the second wavelength (λ2) can be greater than or equal to about 30 nm, greater than or equal to about 50 nm, greater than or equal to about 70 nm, greater than or equal to about 80 nm, or greater than or equal to about 90 nm.

[0110] For example, one of the first wavelength (λ1) and the second wavelength (λ2) can be within a wavelength spectrum of about 750 nm to about 900 nm, and the other of the first wavelength (λ1) and the second wavelength (λ2) can be within a wavelength spectrum of about 800 nm to about 1000 nm.

[0111] The sensor 400 according to some example embodiments includes an optical filter 250, an upper near-infrared light sensor 100, an insulating layer 80, and a semiconductor substrate 40 in which a lower near-infrared light sensor 180 is integrated. The upper near-infrared light sensor 100 and the lower near-infrared light sensor 180 are stacked.

[0112] The optical filter 250 can be disposed at a front side of the sensor 400 and configured to selectively transmit near-infrared light including a first wavelength (λ1) and near-infrared light including a second wavelength (λ2) and block and / or absorb other light. Here, the other light can also include light of an ultraviolet (UV) region and a visible region.

[0113] The upper near-infrared light sensor 100 can be the same as the near-infrared light sensor 100 of the foregoing example embodiments, and a detailed description thereof is omitted. In Figure 4 An example of a near-infrared light sensor 100 including Figure 1 is shown, but is not limited thereto. A near-infrared light sensor 100a including Figure 2 may also be included.

[0114] The lower near-infrared light sensor 180 can be integrated in the semiconductor substrate 40 (e.g., at least partially within the volume 41 defined by the outer surface of the semiconductor substrate 40) and can be a photodiode. The semiconductor substrate 40 can be, for example, a silicon substrate in which the lower near-infrared light sensor 180, the charge storage portion 55, and a transfer transistor (not shown) are integrated.

[0115] The light flowing into the lower near-infrared light sensor 180 can be the light that passes through the optical filter 250 and the upper near-infrared light sensor 100 and can be near-infrared light in a specific (or alternatively predetermined) region including the second wavelength (λ2). Near-infrared light in a specific (or alternatively predetermined) region including the first wavelength (λ1) can be substantially entirely absorbed in the near-infrared photoelectric conversion layer 130 of the upper near-infrared light sensor 100 without reaching the lower near-infrared light sensor 180. Here, a separate wavelength-selective filter for the light flowing into the lower near-infrared light sensor 180 is not required. However, when near-infrared light in a specific (or alternatively predetermined) region including the first wavelength (λ1) is not entirely absorbed in the near-infrared photoelectric conversion layer 130, a filter (not shown) can be additionally provided between the upper near-infrared light sensor 100 and the lower near-infrared light sensor 180.

[0116] The sensor according to some example embodiments can not only include two near-infrared light sensors performing separate functions to function as a combined sensor, but also can maintain the size by stacking two near-infrared light sensors performing separate functions in each pixel and greatly improve the sensitivity by doubling the number of near-infrared light sensors.

[0117] Figure 5 is a cross-sectional view showing an example of a sensor according to some example embodiments.

[0118] Referring to Figure 5 , the sensor 500 according to some example embodiments includes the near-infrared light sensor 100, the visible light sensor 200, and the optical filter 250.

[0119] As described above, the near-infrared light sensor 100 includes the first electrode 110, the second electrode 120, and the near-infrared photoelectric conversion layer 130 disposed between the first electrode 110 and the second electrode 120. The specific details thereof are the same as described above. In Figure 5 , an example of the near-infrared light sensor 100 including Figure 1 is shown, but is not limited thereto. The near-infrared light sensor 100a including Figure 2 may also be included.

[0120] The visible light sensor 200 is a sensor configured to sense light in a visible wavelength spectrum, and can be a photodiode integrated in the semiconductor substrate 40. The visible light sensor 200 can be integrated in the semiconductor substrate 40 (e.g., at least partially within the volume 41 defined by the outer surface of the semiconductor substrate 40), and can include a blue sensor 200a (e.g., a blue photodiode) configured to sense light in a blue wavelength spectrum, a green sensor 200b (e.g., a green photodiode) configured to sense light in a green wavelength spectrum, and a red sensor 200c (e.g., a red photodiode) configured to sense light in a red wavelength spectrum. The blue sensor 200a can be integrated in the blue pixel Pb, the green sensor 200b can be integrated in the green pixel Pg, and the red sensor 200c can be integrated in the red pixel Pr. It will be understood that, as shown in Figure 5

[0121] The semiconductor substrate 40 can be, for example, a silicon substrate, and is integrated with the visible light sensor 200, the charge storage 55, and a transfer transistor (not shown). The visible light sensor 200 can sense light in a visible wavelength range that passes through the optical filter 250, the near-infrared light sensor 100, and the color filter layer 70, and the sensed information can be transferred by the transfer transistor. The charge storage 55 is electrically connected to the near-infrared light sensor 100.

[0122] Metal lines (not shown) and pads (not shown) are formed on the semiconductor substrate 40. To reduce signal delay, the metal lines and pads can be made of a metal having a low resistivity, such as aluminum (Al), copper (Cu), silver (Ag), and alloys thereof, but are not limited thereto. However, not limited to the described structure, the metal lines and pads can be disposed under the blue sensor 200a, the green sensor 200b, and the red sensor 200c.

[0123] A lower insulating layer 60 is formed on the semiconductor substrate 40. The lower insulating layer 60 can be made of an inorganic insulating material, such as silicon oxide and / or silicon nitride, or a low dielectric constant (low-K) material, such as SiC, SiCOH, SiCO, and SiOF.

[0124] ​A color filter layer 70 is formed on the lower insulating layer 60. The color filter layer 70 can include a blue filter 70a configured to selectively transmit light in a blue wavelength spectrum, a green filter 70b configured to selectively transmit light in a green wavelength spectrum, and a red filter 70c configured to selectively transmit light in a red wavelength spectrum. The blue filter 70a, the green filter 70b, and the red filter 70c overlap the blue sensor 200a, the green sensor 200b, and the red sensor 200c, respectively. The blue filter 70a can selectively transmit light in the blue wavelength spectrum, the green filter 70b can selectively transmit light in the green wavelength spectrum, and the red filter 70c can selectively transmit light in the red wavelength spectrum. The transmitted light of the blue wavelength spectrum can flow into the blue sensor 200a, the transmitted light of the green wavelength spectrum can flow into the green sensor 200b, and the transmitted light of the red wavelength spectrum can flow into the red sensor 200c. However, the disclosure is not limited thereto, but at least one of the blue filter 70a, the green filter 70b, and the red filter 70c can be replaced with a yellow filter, a cyan filter, or a magenta filter. Here, the color filter layer 70 is disposed between the near-infrared light sensor 100 and the visible light sensor 200, but is not limited thereto and can be disposed on the near-infrared light sensor 100.

[0125] An upper insulating layer 80 is formed on the color filter layer 70. The upper insulating layer 80 can be, for example, a planarization layer. The lower insulating layer 60 and the upper insulating layer 80 can have a trench 85 that exposes the charge storage portion 55. The trench 85 can be filled with a filler. At least one of the lower insulating layer 60 and the upper insulating layer 80 can be omitted.

[0126] An optical filter 250 is disposed on the visible light sensor 200 and the near-infrared light sensor 100, specifically, on the entire surface of the visible light sensor 200 and the near-infrared light sensor 100. The optical filter 250 can selectively transmit light of a wavelength that is sensed in the visible light sensor 200 and light of a wavelength that is sensed in the near-infrared light sensor 100, but reflect or absorb and thus block light of other wavelengths.

[0127] A focusing lens (not shown) can be further formed on an upper surface or a lower surface of the optical filter 250. The focusing lens can control the direction of incident light and concentrate light in one area. The focusing lens can have, for example, a cylindrical or hemispherical shape, but is not limited thereto.

[0128] Figure 6 is a cross-sectional view illustrating an example of a sensor according to some example embodiments.

[0129] As with the foregoing example embodiment, the sensor 600 according to some example embodiments includes the near-infrared light sensor 100, the visible light sensor 200, and the optical filter 250.

[0130] The near-infrared light sensor 100 includes the first electrode 110, the second electrode 120, and the near-infrared light photoelectric conversion layer 130 provided between the first electrode 110 and the second electrode 120, the specific details of which are the same as described above. In the example of the near-infrared light sensor 100, Figure 6 In the example of the near-infrared light sensor 100, Figure 1 the example of the near-infrared light sensor 100 is shown, but is not limited thereto. The near-infrared light sensor 100a including Figure 2 may also be included.

[0131] The visible light sensor 200 can be a combination of a photodiode integrated in the semiconductor substrate 40 and a photoelectric conversion device provided on the semiconductor substrate 40. As shown in Figure 6 The visible light sensor 200 can include two sensors (e.g., two of the blue sensor 200a, the green sensor 200b, and the red sensor 200c) that are photodiodes integrated in the semiconductor substrate 40 (e.g., the blue sensor 200a and the red sensor 200c within the volume 41 as shown), and the remaining one sensor (e.g., of the blue sensor 200a, the green sensor 200b, and the red sensor 200c) can be a photoelectric conversion device 601 on the semiconductor substrate 40. Figure 6 In the semiconductor substrate 40, the blue sensor 200a, the red sensor 200c, the charge storage portions 55 and 240, and the transfer transistors (not shown) are integrated. The blue sensor 200a and the red sensor 200c are photodiodes and are provided separately from each other in the horizontal direction in the semiconductor substrate 40. The blue sensor 200a is integrated in the blue pixel Pb, and the red sensor 200c is integrated in the red pixel Pr.

[0132] On the semiconductor substrate 40, the lower insulating layer 60 and the color filter layer 70 are formed. The color filter layer 70 includes a blue color filter 70a overlapping the blue sensor 200a and a red color filter 70c overlapping the red sensor 200c.

[0133] The intermediate insulating layer 65 is formed on the color filter layer 70. The lower insulating layer 60 and the intermediate insulating layer 65 can have the trenches 85 and 87 that expose the charge storage portions 55 and 240. The trenches 85 and 87 can be filled with a filler. At least one of the lower insulating layer 60 and the intermediate insulating layer 65 can be omitted.

[0134]

[0135] ​On the intermediate insulating layer 65, a green sensor 200b is formed. The green sensor 200b can be a photoelectric conversion device 601 and is provided on the entire surface of the sensor 600. The green sensor 200b includes a lower electrode 210b and an upper electrode 220b facing each other, and a green photoelectric conversion layer 230b provided between the lower electrode 210b and the upper electrode 220b. Either of the lower electrode 210b and the upper electrode 220b is an anode, and the other is a cathode.

[0136] Either of the lower electrode 210b and the upper electrode 220b can be a light-transmitting electrode. The light-transmitting electrode can be made of, for example, a transparent conductor such as indium tin oxide (ITO), indium zinc oxide (IZO), or can be a metal thin film formed in a thin thickness of several nanometers to several tens of nanometers, or a single layer or a plurality of layers of a metal thin film formed in a thin thickness of several nanometers to several tens of nanometers and doped with a metal oxide.

[0137] The green photoelectric conversion layer 230b can be configured to selectively absorb light in the green wavelength spectrum and allow light from wavelength spectra other than the green wavelength spectrum, that is, the blue wavelength spectrum and the red wavelength spectrum, to pass through. The green photoelectric conversion layer 230b can be formed on the entire surface of the sensor 600. As a result, light in the green wavelength spectrum is configured to be absorbed from the entire surface of the sensor 600, so that the light absorption area increases, thus having a high absorption efficiency.

[0138] The green photoelectric conversion layer 230b can be configured to selectively absorb light of the green wavelength spectrum, form an exciton, and separate the exciton into a hole and an electron, and as the separated hole moves toward the anode, which is one of the lower electrode 210b and the upper electrode 220b, while the separated electron moves toward the cathode, which is the other of the lower electrode 210b and the upper electrode 220b, a photoelectric conversion effect can be obtained. The separated electron and / or hole can be accumulated in the charge storage portion 240.

[0139] An auxiliary layer (not shown) can be further included between the lower electrode 210b and the green photoelectric conversion layer 230b and / or between the upper electrode 220b and the green photoelectric conversion layer 230b. The auxiliary layer can be a charge auxiliary layer, a light absorption auxiliary layer, or a combination thereof, but is not limited thereto.

[0140] Here, an example structure in which the blue sensor 200a and the red sensor 200c are photodiodes and the green sensor 200b is a photoelectric conversion device is described, but is not limited thereto. The blue sensor 200a and the green sensor 200b can be photodiodes and the red sensor 200c can be a photoelectric conversion device, or the green sensor 200b and the red sensor 200c can be photodiodes and the blue sensor 200a can be a photoelectric conversion device. Thus, it will be understood that the photoelectric conversion device 601 can include a visible light photoelectric conversion layer (e.g., 230b) between a pair of electrodes (e.g., 210b and 220b) and configured to absorb visible light of one of a blue wavelength spectrum, a green wavelength spectrum, and a red wavelength spectrum to convert the absorbed visible light into a visible light electric signal.

[0141] On the green sensor 200b, the upper insulating layer 80 is formed, and on the upper insulating layer 80, the near-infrared light sensor 100 and the optical filter 250 are provided. The near-infrared light sensor 100 and the optical filter 250 are the same as described above.

[0142] The sensor 600 according to some example embodiments is a combination sensor equipped with the near-infrared light sensor 100 and the visible light sensor 200 stacked with each other, and the visible light sensor 200 also has a structure of stacking a photodiode and a photoelectric conversion device, and thus the area of the sensor can be further reduced and the size of the sensor can be accordingly downsized.

[0143] Figure 7 is a schematic cross-sectional view showing an example of a sensor according to some example embodiments.

[0144] Referring to Figure 7 As with the foregoing example embodiments, the sensor 700 according to some example embodiments includes the near-infrared light sensor 100, the visible light sensor 200, and the optical filter 250.

[0145] The near-infrared light sensor 100 includes the first electrode 110, the second electrode 120, and the near-infrared light photoelectric conversion layer 130 between the first electrode 110 and the second electrode 120, the specific details of which are the same as described above. In Figure 7 , an example of the near-infrared light sensor 100 including Figure 1 is shown, but is not limited thereto. The near-infrared light sensor 100a including Figure 2 may also be included.

[0146] The visible light sensor 200 includes a blue sensor 200a and a red sensor 200c integrated in the semiconductor substrate 40 and a green sensor 200b on the semiconductor substrate 40. The blue sensor 200a and the red sensor 200c can be photodiodes, and the green sensor 200b can be a photoelectric conversion device. The green sensor 200b includes a lower electrode 210b, a green photoelectric conversion layer 230b, and an upper electrode 220b.

[0147] However, in the sensor 700 according to some example embodiments, the blue sensor 200a and the red sensor 200c integrated in the semiconductor substrate 40 are stacked in the vertical direction. The blue sensor 200a and the red sensor 200c can be configured to selectively absorb and sense light of a respective wavelength spectrum depending on the depth of the stack. In other words, the red sensor 200c configured to absorb red light of a long wavelength spectrum can be disposed deeper from the surface of the semiconductor substrate 40 than the blue sensor 200a configured to absorb blue light of a short wavelength spectrum. In this way, by separating the absorption wavelengths depending on the depth of the stack, the color filter layer 70 can be omitted.

[0148] Here, an example structure is described in which the blue sensor 200a and the red sensor 200c are photodiodes and the green sensor 200b is a photoelectric conversion device, but is not limited thereto. The blue sensor 200a and the green sensor 200b can be photodiodes and the red sensor 200c can be a photoelectric conversion device, or the green sensor 200b and the red sensor 200c can be photodiodes and the blue sensor 200a can be a photoelectric conversion device.

[0149] The sensor 700 according to some example embodiments is a combination sensor equipped with the near-infrared light sensor 100 and the visible light sensor 200 stacked with each other, and here, because the visible light sensor 200 can also be equipped with a photodiode and a photoelectric conversion device stacked with each other, and the photodiode also has a stacked structure, the area of the sensor can be further reduced, and thus the size of the sensor can be reduced. Furthermore, the sensor 700 according to some example embodiments can not include a separate color filter layer, thus simplifying the structure and the process.

[0150] Figure 8 is a schematic cross-sectional view showing an example of a sensor according to some example embodiments.

[0151] Referring to Figure 8 As with the foregoing example embodiments, the sensor 800 according to some example embodiments includes the near-infrared light sensor 100, the visible light sensor 200, and the optical filter 250.

[0152] The near-infrared light sensor 100 includes a first electrode 110, a second electrode 120, and a near-infrared light photoelectric conversion layer 130 between the first electrode 110 and the second electrode 120, the details of which are the same as described above. In Figure 8 , an example of the near-infrared light sensor 100 including Figure 1 is shown, but is not limited thereto. A near-infrared light sensor 100a including Figure 2 may also be included.

[0153] The visible light sensor 200 includes a blue sensor 200a, a green sensor 200b, and a red sensor 200c integrated in the semiconductor substrate 40. The blue sensor 200a, the green sensor 200b, and the red sensor 200c are stacked in the vertical direction in the semiconductor substrate 40. The blue sensor 200a, the green sensor 200b, and the red sensor 200c can separate the absorption wavelength according to the stacking depth, and thus a color filter layer 70 can be omitted. An insulating layer 80 is formed between the semiconductor substrate 40 and the near-infrared light sensor 100, and the insulating layer 80 has a trench 85. The semiconductor substrate 40 includes a charge storage portion 55 connected to the near-infrared light sensor 100.

[0154] Figure 9 is a perspective view showing an example of a sensor according to some example embodiments, Figure 10 is a schematic cross-sectional view showing an example of the sensor shown in Figure 9 .

[0155] Referring to Figure 9 and Figure 10 , a sensor 900 according to some example embodiments includes a semiconductor substrate 40, a near-infrared light sensor 100, a visible light sensor 200, an insulating layer 80, and an optical filter 250. The visible light sensor 200 includes a blue sensor 200a, a green sensor 200b, and a red sensor 200c. As shown in Figure 9 and Figure 10 , each of the blue sensor 200a, the green sensor 200b, and the red sensor 200c can be a photoelectric conversion device.

[0156] The near-infrared light sensor (IR) 100, the blue sensor (B) 200a, the green sensor (G) 200b, and the red sensor (R) 200c can be stacked in the horizontal direction on the semiconductor substrate 40 and can be connected to charge storage portions 55, 240a, 240b, and 240c, respectively, integrated in the semiconductor substrate 40.

[0157] The near-infrared light sensor 100, the blue sensor 200a, the green sensor 200b, and the red sensor 200c are each a photoelectric conversion device.

[0158] The near-infrared light sensor 100 includes a first electrode 110, a second electrode 120, and a near-infrared photoelectric conversion layer 130 disposed between the first electrode 110 and the second electrode 120, the details of which are the same as described above. In Figure 9 and Figure 10 , an example of the near-infrared light sensor 100 including Figure 1 is shown, but is not limited thereto. A near-infrared light sensor 100a including Figure 2 may also be included.

[0159] The blue sensor 200a includes a lower electrode 210a, a blue photoelectric conversion layer 230a, and an upper electrode 220a. The green sensor 200b includes a lower electrode 210b, a green photoelectric conversion layer 230b, and an upper electrode 220b. The red sensor 200c includes a lower electrode 210c, a red photoelectric conversion layer 230c, and an upper electrode 220c. The blue photoelectric conversion layer 230a can be configured to selectively absorb light in a blue wavelength spectrum to perform photoelectric conversion, the green photoelectric conversion layer 230b can be configured to selectively absorb light in a green wavelength spectrum to perform photoelectric conversion, and the red photoelectric conversion layer 230c can be configured to selectively absorb light in a red wavelength spectrum to perform photoelectric conversion. Restated, the blue sensor 200a includes a blue photoelectric conversion layer 230a configured to absorb light in a blue wavelength spectrum (e.g., first light) and convert the light into a first electrical signal, the green sensor 200b includes a green photoelectric conversion layer 230b configured to absorb light in a green wavelength spectrum (e.g., second light) and convert the light into a second electrical signal, and the red sensor 200c includes a red photoelectric conversion layer 230c configured to absorb light in a red wavelength spectrum (e.g., third light) and convert the light into a third electrical signal.

[0160] Figure 11 is a perspective view showing an example of a sensor according to some example embodiments, Figure 12 is a schematic cross-sectional view showing an example of the sensor shown in Figure 11 .

[0161] Referring to Figure 11 and Figure 12 , a sensor 1000 according to some example embodiments includes a semiconductor substrate 40, a near-infrared light sensor 100, a visible light sensor 200, and an optical filter 250. The visible light sensor 200 includes a blue sensor 200a, a green sensor 200b, and a red sensor 200c. As shown in Figure 11 and Figure 12 , each of the blue sensor 200a, the green sensor 200b, and the red sensor 200c can be a photoelectric conversion device.

[0162] The near-infrared light sensor 100, the blue sensor 200a, the green sensor 200b, and the red sensor 200c can be stacked in a vertical direction on the semiconductor substrate 40, and can be connected to the charge storage portions 55, 240a, 240b, and 240c, respectively, integrated in the semiconductor substrate 40.

[0163] The near-infrared light sensor 100 includes a first electrode 110, a second electrode 120, and a near-infrared photoelectric conversion layer 130 between the first electrode 110 and the second electrode 120, the details of which are the same as described above. In Figure 11 and Figure 12 Examples of the near-infrared light sensor 100 including Figure 1 are shown, but are not limited thereto. The near-infrared light sensor 100a including Figure 2 may also be included.

[0164] The blue sensor 200a includes a lower electrode 210a, a blue photoelectric conversion layer 230a, and an upper electrode 220a. The green sensor 200b includes a lower electrode 210b, a green photoelectric conversion layer 230b, and an upper electrode 220b. The red sensor 200c includes a lower electrode 210c, a red photoelectric conversion layer 230c, and an upper electrode 220c. In some example embodiments, the blue sensor 200a includes a blue photoelectric conversion layer 230a configured to absorb light in a blue wavelength spectrum (e.g., first light) and convert the light into a first electrical signal, the green sensor 200b includes a green photoelectric conversion layer 230b configured to absorb light in a green wavelength spectrum (e.g., second light) and convert the light into a second electrical signal, and the red sensor 200c includes a red photoelectric conversion layer 230c configured to absorb light in a red wavelength spectrum (e.g., third light) and convert the light into a third electrical signal.

[0165] Insulating layers 80a, 80b, 80c, and 80d are respectively provided between the semiconductor substrate 40 and the blue sensor 200a, between the blue sensor 200a and the green sensor 200b, between the green sensor 200b and the red sensor 200c, and between the red sensor 200c and the near-infrared light sensor 100.

[0166] In some example embodiments, a structure in which the blue sensor 200a, the green sensor 200b, the red sensor 200c, and the near-infrared light sensor 100 are sequentially stacked is exemplarily shown, but the present disclosure can have a variety of stacking orders without being limited thereto.

[0167] The aforementioned sensors can be applied to various electronic devices such as mobile phones, digital cameras, biometric identification devices, and / or automotive electronic components, but are not limited thereto.

[0168] Figure 13 is a schematic diagram of an electronic device according to some example embodiments.

[0169] Reference Figure 13 , electronic device 1300 includes a processor 1320, a memory 1330, a sensor 1340, and a display device 1350 electrically connected via a bus 1310. Sensor 1340 can be any of the various sensors (100, 300, 400, 500, 600, 700, 800, 900, 1000) described above. Processor 1320 can execute a program stored in the memory and thereby perform at least one function. Processor 1320 can additionally execute the program stored in the memory to display an image on display device 1350. Processor 1320 can generate an output.

[0170] Hereinafter, some exemplary embodiments are described in more detail with reference to examples. However, the scope of the present disclosure is not limited thereto.

[0171] Example

[0172] Example 1

[0173] ITO was sputtered onto a glass substrate to form a 150 nm thick anode (work function: 4.7 eV). On the anode, a compound represented by Chemical Formula A was deposited to form a 10 nm thick electron blocking layer. On the electron blocking layer, a first material (λ) represented by Chemical Formula B was co-deposited at a thickness ratio (volume ratio) of 0.10:1. max : 870nm, HOMO: 5.1eV, LUMO: 4.0eV) and C 60 The second material (λ max A 165nm thick near-infrared photoelectric conversion layer (with a work function of 4.5eV) was formed by sputtering ITO on the near-infrared photoelectric conversion layer. A 50nm thick antireflection layer was formed by depositing aluminum oxide (Al2O3) on the cathode, and then sealed with a glass plate to produce a near-infrared light sensor.

[0174] [Chemical Formula A]

[0175]

[0176] [Chemical Formula B]

[0177]

[0178] Example 2

[0179] A near-infrared light sensor was manufactured according to the same method as Example 1 except that the first material and the second material were co-deposited to form a 190 nm-thick near-infrared photoelectric conversion layer in a thickness ratio (volume ratio) of 0.27:1.

[0180] Example 3

[0181] A near-infrared light sensor was manufactured according to the same method as Example 1 except that the first material and the second material were co-deposited to form a 190 nm-thick near-infrared photoelectric conversion layer in a thickness ratio (volume ratio) of 0.27:1.

[0182] Example 4

[0183] A near-infrared light sensor was manufactured according to the same method as Example 1 except that the first material and the second material were co-deposited to form a 225 nm-thick near-infrared photoelectric conversion layer in a thickness ratio (volume ratio) of 0.50:1.

[0184] Example 5

[0185] A near-infrared light sensor was manufactured according to the same method as Example 1 except that the first material and the second material were co-deposited to form a 240 nm-thick near-infrared photoelectric conversion layer in a thickness ratio (volume ratio) of 0.20:1.

[0186] Example 6

[0187] A near-infrared light sensor was manufactured according to the same method as Example 1 except that the first material and the second material were co-deposited to form a 254 nm-thick near-infrared photoelectric conversion layer in a thickness ratio (volume ratio) of 0.27:1.

[0188] Example 7

[0189] A near-infrared light sensor was manufactured according to the same method as Example 1 except that the first material and the second material were co-deposited to form a 330 nm-thick near-infrared photoelectric conversion layer in a thickness ratio (volume ratio) of 0.32:1.

[0190] Example 8

[0191] A near-infrared light sensor was manufactured according to the same method as Example 1 except that the first material and the second material were co-deposited to form a 400 nm-thick near-infrared photoelectric conversion layer in a thickness ratio (volume ratio) of 0.33:1.

[0192] Example 9

[0193] A near-infrared light sensor was manufactured according to the same method as Example 1 except that the first material and the second material were co-deposited to form a 280 nm-thick near-infrared photoelectric conversion layer in a thickness ratio (volume ratio) of 0.40:1.

[0194] Example 10

[0195] The near-infrared light sensor was manufactured according to the same method as Example 1 except that the first material and the second material were co-deposited to form a 330 nm-thick near-infrared photoelectric conversion layer in a thickness ratio (volume ratio) of 0.32:1 and only the second material was deposited on the near-infrared photoelectric conversion layer to form a 30 nm-thick auxiliary layer.

[0196] Reference Example

[0197] The near-infrared light sensor was manufactured according to the same method as Example 1 except that the first material and the second material were co-deposited to form a 200 nm-thick near-infrared photoelectric conversion layer in a thickness ratio (volume ratio) of 1:1.

[0198] Evaluation I

[0199] The dark current of each of the near-infrared light sensors according to the examples and the reference example was evaluated under a reverse bias.

[0200] The dark current was measured by using a current-voltage evaluation device (Keithley K4200 parameter analyzer) after a heat treatment at 170℃ for 3 hours, and then the dark current density was evaluated by dividing the unit pixel area (0.04 cm 2 ) by the current flowing at the time of applying a -3V reverse bias.

[0201] The results are shown in Table 1.

[0202] Table 1

[0203] Dark current density (h / s / μm 2 ) Example 1 127,318 Example 2 79,861 Example 3 472,442 Example 4 829,462 Example 5 273,664 Example 6 191,366 Example 7 330,462 Example 8 274,702 Example 9 629,236 Example 10 287,936 Reference Example 94,701,400

[0204] Referring to Table 1, the near-infrared light sensor according to the examples exhibited a greatly reduced dark current compared to the near-infrared light sensor according to the reference example.

[0205] Evaluation II

[0206] The photoelectric conversion efficiency of the near-infrared light sensors according to the examples and the reference example was evaluated. The photoelectric conversion efficiency was evaluated from the external quantum efficiency (EQE) using the incident photon-to-current efficiency (IPCE) method in the wavelength spectrum of 800 nm to 1300 nm after a heat treatment at 170℃ for 3 hours.

[0207] The results are shown in Table 2.

[0208] Table 2

[0209] EQE (at 870 nm) (%) Example 1 18.4 Example 2 31.6 Example 3 31.4 Example 4 28.9 Example 5 14.7 Example 6 17.8 Example 7 17.1 Example 8 22.2 Example 9 27.9 Example 10 26.5 Reference Example 15.0

[0210] Referring to Table 2, the near-infrared light sensor according to the example exhibited equivalent or improved photoelectric conversion efficiency compared to the near-infrared light sensor according to the reference example.

[0211] Collectively examining the results, the near-infrared light sensor according to the example exhibited greatly reduced dark current under reverse bias and had equivalent or improved photoelectric conversion efficiency compared to the near-infrared light sensor according to the reference example.

[0212] While the disclosure has been described in connection with what is presently considered to be practical example implementations, it is to be understood that the inventive concept is not limited to the disclosed example implementations. On the contrary, it is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.

[0213] This application claims priority to and the benefit of Korean Patent Application No. 10-2019-0093974, filed in the Korean Intellectual Property Office on August 1, 2019, the entire contents of which are incorporated herein by reference.

Claims

1. A sensor comprising a near-infrared light sensor, the near-infrared light sensor comprising: an anode and a cathode; and a near-infrared photoelectric conversion layer between the anode and the cathode, the near-infrared photoelectric conversion layer configured to absorb light of at least a portion of a near-infrared wavelength spectrum and convert the absorbed light into an electrical signal, wherein the near-infrared photoelectric conversion layer comprises: a first amount of a first material, the first material having a maximum absorption wavelength in the near-infrared wavelength spectrum; and a second amount of a second material, the second material forming a pn junction with the first material, the second material having an energy band gap wider than an energy band gap of the first material, wherein the first material is a p-type semiconductor and the second material is an n-type semiconductor, and wherein the first amount is less than the second amount.

2. The sensor according to claim 1, wherein a difference between a highest occupied molecular orbital energy level of the first material and a work function of the cathode is less than 1.0 eV.

3. The sensor according to claim 1, wherein a difference between a highest occupied molecular orbital energy level of the second material and a highest occupied molecular orbital energy level of the first material is greater than or equal to 1.0 eV.

4. The sensor according to claim 1, wherein a difference between a highest occupied molecular orbital energy level of the second material and a work function of the cathode is greater than or equal to 1.5 eV.

5. The sensor according to claim 1, wherein the energy band gap of the second material is 0.5 eV to 2.0 eV wider than the energy band gap of the first material.

6. The sensor according to claim 1, wherein a maximum absorption wavelength of the second material is not within the near-infrared wavelength spectrum.

7. The sensor according to claim 1, wherein a composition ratio of the first material with respect to the second material is 0.10 to 0.

90.

8. The sensor according to claim 1, wherein a composition ratio of the first material with respect to the second material is 0.10 to 0.

50.

9. The sensor according to claim 1, wherein the near-infrared photoelectric conversion layer comprises a mixed layer, the mixed layer comprising a mixture of the first material and the second material.

10. The sensor according to claim 1, wherein a maximum absorption wavelength of the near-infrared photoelectric conversion layer is within 750 nm to 1500 nm.

11. The sensor according to claim 1, further comprising: a charge assisting layer between the near-infrared photoelectric conversion layer and the cathode.

12. The sensor according to claim 11, wherein a difference between a highest occupied molecular orbital energy level of the charge assisting layer and a work function of the cathode is greater than or equal to 1.5 eV.

13. The sensor according to claim 1, further comprising: a charge assisting layer between the near-infrared photoelectric conversion layer and the anode.

14. The sensor according to claim 13, wherein a difference between a lowest unoccupied molecular orbital energy level of the charge assisting layer and a work function of the anode is greater than or equal to 1.5 eV.

15. The sensor according to claim 1, further comprising: ​ A semiconductor substrate, wherein the cathode, the anode, and the near-infrared photoelectric conversion layer are stacked on the semiconductor substrate.

16. The sensor of claim 15, further comprising: a visible light sensor configured to detect light in a visible wavelength spectrum.

17. The sensor of claim 16, wherein the visible light sensor comprises: a blue sensor configured to sense light in a blue wavelength spectrum; a green sensor configured to sense light in a green wavelength spectrum; and a red sensor configured to sense light in a red wavelength spectrum, wherein the blue sensor, the green sensor, and the red sensor are integrated in the semiconductor substrate.

18. The sensor of claim 16, wherein the visible light sensor comprises: a blue sensor configured to sense light in a blue wavelength spectrum; a green sensor configured to sense light in a green wavelength spectrum; and a red sensor configured to sense light in a red wavelength spectrum, wherein two of the blue sensor, the green sensor, and the red sensor are photodiodes integrated in the semiconductor substrate, and the remaining one of the blue sensor, the green sensor, and the red sensor is a photoelectric conversion device on the semiconductor substrate.

19. The sensor of claim 18, wherein the photoelectric conversion device comprises a visible photoelectric conversion layer between a pair of electrodes, the visible photoelectric conversion layer configured to absorb visible light in one of the blue wavelength spectrum, the green wavelength spectrum, and the red wavelength spectrum to convert the absorbed visible light into a visible photoelectric signal.

20. The sensor of claim 16, wherein the visible light sensor comprises: a blue sensor configured to sense light in a blue wavelength spectrum; a green sensor configured to sense light in a green wavelength spectrum; and a red sensor configured to sense light in a red wavelength spectrum, wherein each of the blue sensor, the green sensor, and the red sensor is a photoelectric conversion device.

21. The sensor of claim 20, wherein the blue sensor comprises a blue photoelectric conversion layer configured to absorb a first light in the blue wavelength spectrum and convert the first light into a first electrical signal, the green sensor comprises a green photoelectric conversion layer configured to absorb a second light in the green wavelength spectrum and convert the second light into a second electrical signal, and the red sensor comprises a red photoelectric conversion layer configured to absorb a third light in the red wavelength spectrum and convert the third light into a third electrical signal.

22. An electronic device comprising the sensor of claim 1. ​ ​

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