Devices and methods of making and use thereof

Abstract

Disclosed herein are devices and methods of making and use thereof. For example, disclosed herein are devices comprising: a first contact layer; a semiconductor layer comprising a semiconductor material having a first bandgap; and a dielectric layer comprising a dielectric material; wherein the first contact layer is disposed on top of and in physical contact with the dielectric layer, and the dielectric layer is disposed on top of and in physical contact with the semiconductor layer, such that the dielectric layer is sandwiched between and in physical contact with both the first contact layer and the semiconductor layer; wherein the dielectric layer suppresses photoemission of carriers between the first contact layer and the semiconductor layer under incident light. Also disclosed herein are methods of use of any of the devices disclosed herein. In some examples, the method comprises using the device as a solar blind photodetector.

Description

[0001] DEVICES AND METHODS OF MAKING AND USE THEREOF

[0002] CROSS-REFERENCE TO RELATED APPLICATIONS

[0003] This application claims the benefit of priority to U.S. Provisional Application No. 63 / 532,742 filed August 15, 2023, which is hereby incorporated herein by reference in its entirety.

[0004] STATEMENT OF GOVERNMENT SUPPORT

[0005] This invention was made with government support under grant no. FA9950-22- 1-0527 and FA9550-18-1-0479 awarded by the Air Force Office of Scientific Research. The government has certain rights in the invention.

[0006] BACKGROUND

[0007] UV solar-blind photodetectors have applications in many areas of industry. Ultra-wide bandgap materials are excellent candidates for UV Solar blind photodetectors in that they do not require the complex optical filters required to make a solar blind UV photodetector out of lower bandgap materials like silicon. Unfortunately, many detectors have very low UV-Visible rejection ratios. Devices with improved properties, such as improved UV-Vis rejection ratios, are needed. The compositions, methods, and devices discussed herein addresses these and other needs.

[0008] SUMMARY

[0009] In accordance with the purposes of the disclosed compositions, methods, and devices as embodied and broadly described herein, the disclosed subject matter relates to devices and methods of making and use thereof. For example, disclosed herein are solar blind photodetectors.

[0010] For example, disclosed herein are devices comprising: a first contact layer; a semiconductor layer comprising a semiconductor material having a first bandgap; and a dielectric layer comprising a dielectric material; wherein the first contact layer is disposed on top of and in physical contact with the dielectric layer, and the dielectric layer is disposed on top of and in physical contact with the semiconductor layer, such that the dielectric layer is sandwiched between and in physical contact with both the first contact layer and the semiconductor layer; wherein the dielectric layer suppresses photoemission of carriers between the first contact layer and the semiconductor layer under incident light.

[0011] In some examples, the dielectric layer allows holes to exit the semiconductor layer and be collected at the first contact layer.

[0012] In some examples, the device has a positive conduction band offset and a negative valence band offset. In some examples, the first contact layer comprises a first metal. In some examples, the first metal comprises Ni, Pt, or a combination thereof. In some examples, the first metal comprises Pt.

[0013] In some examples, the first contact layer comprises a first electrode.

[0014] In some examples, the first contact layer comprises a first portion and a second portion, the first portion being a cathode and the second portion being an anode. In some examples, the dielectric layer comprises a first portion with a first thickness and a second portion with a second thickness, the first portion being in contact with the cathode and the second portion being in contact with the anode, wherein the first thickness and the second thickness can be the same or different. In some examples, the dielectric layer further comprises a third portion with a third thickness, the third portion extending from the first portion to the second portion, wherein the third thickness can be the same or different than the first thickness and / or the second thickness.

[0015] In some examples, the device further comprises a second contact layer, wherein the semiconductor layer is disposed on top of and in physical contact with the second contact layer such that the semiconductor layer is sandwiched between and in physical contact with the dielectric layer and the second contact layer. In some examples, the second contact layer comprises a second metal. In some examples, the second metal comprises Ti, Au, or a combination thereof. In some examples, the second contact layer comprises a second electrode.

[0016] In some examples, the first contact layer and / or the second contact layer (when present) has an average thickness of 100 nanometers (nm) or less, or 50 nanometers (nm) or less.

[0017] In some examples, the semiconductor layer further comprises a dopant.

[0018] In some examples, the semiconductor material comprises Ga2Ch, (Al,Ga)2Ch, SiC, (Al,Ga)N, GaN, diamond, Ge2O, or a combination thereof.

[0019] In some examples, the semiconductor material comprises the pseudo binary alloy (Al,Ga)2Ch, or SiC, or (Al,Ga)N to enable band-to-band absorption and photo response in the ultraviolet range.

[0020] In some examples, the semiconductor layer has an average thickness of from 1 nm to 100 pm, such as from 1 nm to 10 pm.

[0021] In some examples, the semiconductor layer comprises a first portion comprising a first semiconductor material and a second portion comprising a second semiconductor material, the first portion being disposed on top of the second portion, such that the first portion is sandwiched between and in physical contact with both the dielectric layer and the second portion. In some examples, the first portion has a first thickness and the second portion has a second thickness, the first thickness and the second thickness being the same or different. In some examples, the first semiconductor material further comprises a first dopant in a first concentration; wherein the second semiconductor material further comprises a second dopant in a second concentration; or a combination thereof. In some examples, the first semiconductor material and the second semiconductor material are different, the first dopant and the second dopant are different, the first concentration and the second concentration are different, or a combination thereof. In some examples, the first semiconductor material and the second semiconductor material are different. In some examples, the first semiconductor material and the second semiconductor material are the same.

[0022] In some examples, the dielectric material comprises a high-K dielectric material.

[0023] In some examples, the dielectric material comprises hafnium silicate, zirconium silicate, hafnium oxide, barium titanate, barium-strontium titanate, zirconium dioxide, titanium dioxide, silicon nitride, aluminum oxide, aluminum nitride, magnesium oxide, or a combination thereof.

[0024] In some examples, the dielectric material comprises (BaxSri-x)TiO3, where x is from 0 to 1. In some examples, the dielectric material comprises BaTiCh.

[0025] In some examples, the dielectric layer has an average thickness of from 2 to 100 nanometers (nm), such as from 2 to 20 nm, or from 2 nm to 10 nm.

[0026] In some examples, the dielectric layer comprises two or more dielectric materials, wherein each of the two or more dielectric materials is selected to further suppress the photoemission of carriers between the first contact layer and the semiconductor.

[0027] In some examples, the dielectric layer comprises a first layer comprising a first dielectric material and a second layer comprising a second dielectric material, the first layer being disposed on top of the second layer, such that the first layer is sandwiched between and in physical contact with both the first contact layer and the second layer, and the second layer is sandwiched between and in physical contact with the first layer and the semiconductor layer. In some examples, the first layer has a first thickness and the second layer has a second thickness, the first thickness and the second thickness being the same or different. In some examples, the first dielectric material and the second dielectric material are different. In some examples, the first dielectric material comprises BaTiCh and the second dielectric material comprises AI2O3, AIN, or a combination thereof.

[0028] In some examples, the semiconductor layer comprises a first portion comprising a first semiconductor material and a second portion comprising a second semiconductor material; and the dielectric layer comprises a first layer comprising a first dielectric material and a second layer comprising a second dielectric material; the first layer is disposed on top of and in physical contact with the second layer, such that the first layer is sandwiched between and in physical contact with the first contact layer and the second layer; and the first portion is disposed on top of and in physical contact with the second portion, such that the first portion is sandwiched between and in physical contact with the second layer and the second portion.

[0029] In some examples, the device comprises a solar blind photodetection device.

[0030] In some examples, the device exhibits a UV-Vis rejection ratio that is higher than the UV-Vis rejection ratio for a comparable device in the absence of the dielectric layer.

[0031] In some examples, the device exhibits a UV-Vis rejection ratio of 1 x 103to 1 x IO10.

[0032] Also disclosed herein are methods of making any of the devices disclosed herein. In some examples, the method comprises depositing, in any order, the first contact layer, the semiconductor layer, the dielectric layer, and the second contact layer (when present).

[0033] Also disclosed herein are methods of use of any of the devices disclosed herein. In some examples, the method comprises using the device as a solar blind photodetector.

[0034] Also disclosed herein are solar blind photodetection devices comprising a dielectric layer comprising BaTiCh disposed on and in physical contact with a semiconductor layer comprising Ga2O3.

[0035] Also disclosed herein are solar blind photodetection devices comprising any of the devices disclosed herein.

[0036] Also disclosed herein are methods of use of any of the solar blind photodetectors disclosed herein. In some examples, the methods comprise using the solar blind photodetector for medical imaging, fire detection, photonic communication, defense application, or a combination thereof.

[0037] Additional advantages of the disclosed compositions, devices, and methods will be set forth in part in the description which follows, and in part will be obvious from the description. The advantages of the disclosed compositions, devices, and methods will be realized and attained by means of the elements and combinations particularly pointed out in the appended claims. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosed devices and methods, as claimed.

[0038] The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the claims. BRIEF DESCRIPTION OF THE FIGURES

[0039] The accompanying figures, which are incorporated in and constitute a part of this specification, illustrate several aspects of the disclosure, and together with the description, serve to explain the principles of the disclosure. However, the present disclosure is not limited to the precise arrangements shown, and the drawings are not necessarily drawn to scale.

[0040] Figure l is a schematic cross-sectional view of an example device with BaTiOs as disclosed herein according to one implementation.

[0041] Figure 2 is a schematic cross-sectional view of an example device without BaTiCh as disclosed herein according to one implementation.

[0042] Figure 3 is a plot of light and dark IV curves for both device designs up to 50V reverse bias.

[0043] Figure 4 is a plot of spectral response curves for both device designs. Without BaTiCh, the detector shows a UV-Vis- rejection ratio on the order of 102. With BaTiOs, the detector shows a UV-Vis rejection ratio on the order of 107.

[0044] Figure 5 is a schematic diagram of a structure including a dielectric.

[0045] Figure 6 is a schematic flat band voltage diagram of a device including AI2O3 (k: 9).

[0046] Figure 7 is a schematic flat band voltage diagram of a device including TiCh (k: 80).

[0047] Figure 8 is a schematic flat band voltage diagram of a device including BaTiCh (k: 40).

[0048] Figure 9 is a schematic diagram of the electromagnetic spectrum showing the solar blind region.

[0049] Figure 10 is the solar spectrum, showing the low levels of UV radiation at sea level.

[0050] Figure 11 is a schematic illustration of issues with dielectric integration.

[0051] Figure 12 is a band diagram of Ni / Ga2Ch interface, showing a Schottky barrier of ~1 eV.

[0052] Figure 13 is a band diagram of Ni / BaTiO3 / Ga2O3 heterostructure, showing an increased barrier to electrons.

[0053] Figure 14 is a schematic illustration of an example device design.

[0054] Figure 15 is a schematic illustration of the fabrication of 10 pm HVPE Ga2O3 / BaTiO3 trench structures.

[0055] Figure 16 is a schematic illustration of the fabrication of 10 pm HVPE Ga2O3 / BaTiO3 trench structures.

[0056] Figure 17 shows the spectral responsivity of the 10 pm HVPE Ga2O3 / BaTiO3 trench structure at 305 K in log scale.

[0057] Figure 18 shows the IV curves of the 10 pm HVPE Ga2O3 / BaTiO3 trench structure with (light) and without (dark) 258 nm illumination. Figure 19 shows the photodetector absorption.

[0058] Figure 20 shows the BaTiCh absorption.

[0059] Figure 21 is a schematic illustration of an example second generation device design.

[0060] Figure 22 shows the equilibrium band diagram.

[0061] Figure 23 is a schematic illustration of the fabrication of 1 pm MOCVD Ga2O3 / BaTiO3 structure.

[0062] Figure 24 shows the responsivity of the 1 pm MOCVD Ga2O3 / BaTiO3 structure.

[0063] Figure 25 shows the light and dark IV curves of the 1 pm MOCVD Ga2O3 / BaTiO3 structure.

[0064] Figure 26 shows the gain of the 1 pm MOCVD Ga2O3 / BaTiO3 structure.

[0065] Figure 27A is an energy band diagram of BaTiOs on Ga2O3.

[0066] Figure 27B is an energy band diagram of MgO on Ga2O3.

[0067] Figure 27C is an energy band diagram of SiO2 on Ga2O3.

[0068] Figure 28 is a schematic diagram of an example device as disclosed herein according to one implementation.

[0069] Figure 29 is a schematic diagram of an example device as disclosed herein according to one implementation.

[0070] Figure 30 is a schematic diagram of an example device as disclosed herein according to one implementation.

[0071] Figure 31 is a schematic diagram of an example device as disclosed herein according to one implementation.

[0072] Figure 32 is a schematic diagram of an example device as disclosed herein according to one implementation.

[0073] Figure 33 is a schematic diagram of an example device as disclosed herein according to one implementation.

[0074] Figure 34 is a schematic diagram of an example device as disclosed herein according to one implementation.

[0075] Figure 35 is a schematic diagram of an example device as disclosed herein according to one implementation.

[0076] Figure 36 is a schematic diagram of an example device as disclosed herein according to one implementation.

[0077] Figure 37 is a schematic diagram of an example device as disclosed herein according to one implementation. Figure 38 is a schematic diagram of an example device as disclosed herein according to one implementation.

[0078] Figure 39 is a schematic diagram of an example device as disclosed herein according to one implementation.

[0079] Figure 40 is a schematic diagram of an example device as disclosed herein according to one implementation.

[0080] Figure 41 is a schematic diagram of an example device as disclosed herein according to one implementation.

[0081] DETAILED DESCRIPTION

[0082] The compositions, methods, and devices described herein may be understood more readily by reference to the following detailed description of specific aspects of the disclosed subject matter and the Examples included therein.

[0083] Before the present compositions, methods, and devices are disclosed and described, it is to be understood that the aspects described below are not limited to specific synthetic methods or specific reagents, as such may, of course, vary. It is also to be understood that the terminology used herein is for the purpose of describing particular aspects only and is not intended to be limiting.

[0084] Also, throughout this specification, various publications are referenced. The disclosures of these publications in their entireties are hereby incorporated by reference into this application in order to more fully describe the state of the art to which the disclosed matter pertains. The references disclosed are also individually and specifically incorporated by reference herein for the material contained in them that is discussed in the sentence in which the reference is relied upon.

[0085] In this specification and in the claims that follow, reference will be made to a number of terms, which shall be defined to have the following meanings.

[0086] Throughout the description and claims of this specification the word “comprise” and other forms of the word, such as “comprising” and “comprises,” means including but not limited to, and is not intended to exclude, for example, other additives, components, integers, or steps.

[0087] As used in the description and the appended claims, the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to “a composition” includes mixtures of two or more such compositions, reference to “an agent” includes mixtures of two or more such agents, reference to “the component” includes mixtures of two or more such components, and the like. “Optional” or “optionally” means that the subsequently described event or circumstance can or cannot occur, and that the description includes instances where the event or circumstance occurs and instances where it does not.

[0088] Ranges can be expressed herein as from “about” one particular value, and / or to “about” another particular value. By “about” is meant within 5% of the value, e.g., within 4, 3, 2, or 1% of the value. When such a range is expressed, another aspect includes from the one particular value and / or to the other particular value. Similarly, when values are expressed as approximations, by use of the antecedent “about,” it will be understood that the particular value forms another aspect. It will be further understood that the endpoints of each of the ranges are significant both in relation to the other endpoint, and independently of the other endpoint.

[0089] Values can be expressed herein as an “average” value. “Average” generally refers to the statistical mean value.

[0090] By “substantially” is meant within 5%, e.g., within 4%, 3%, 2%, or 1%.

[0091] “Exemplary” means “an example of’ and is not intended to convey an indication of a preferred or ideal embodiment. “Such as” is not used in a restrictive sense, but for explanatory purposes.

[0092] It is understood that throughout this specification the identifiers “first” and “second” are used solely to aid in distinguishing the various components and steps of the disclosed subject matter. The identifiers “first” and “second” are not intended to imply any particular order, amount, preference, or importance to the components or steps modified by these terms.

[0093] References in the specification and concluding claims to parts by weight of a particular element or component in a composition denotes the weight relationship between the element or component and any other elements or components in the composition or article for which a part by weight is expressed. Thus, in a compound containing 2 parts by weight of component X and 5 parts by weight component Y, X and Y are present at a weight ratio of 2:5, and are present in such ratio regardless of whether additional components are contained in the compound.

[0094] A weight percent (wt. %) of a component, unless specifically stated to the contrary, is based on the total weight of the formulation or composition in which the component is included.

[0095] The term “or combinations thereof’ as used herein refers to all permutations and combinations of the listed items preceding the term. For example, “A, B, C, or combinations thereof’ is intended to include at least one of: A, B, C, AB, AC, BC, or ABC, and if order is important in a particular context, also BA, CA, CB, CBA, BCA, ACB, BAC, or CAB. Continuing with this example, expressly included are combinations that contain repeats of one or more item or term, such as BB, AAA, AB, BBC, AAABCCCC, CBBAAA, CAB ABB, and so forth. The skilled artisan will understand that typically there is no limit on the number of items or terms in any combination, unless otherwise apparent from the context.

[0096] Devices

[0097] Referring now to Figure 28, disclosed herein are devices 100 comprising: a first contact layer 110; a semiconductor layer 130 comprising a semiconductor material having a first bandgap; and a dielectric layer 120 comprising a dielectric material; wherein the first contact layer 110 is disposed on top of and in physical contact with the dielectric layer 120, and the dielectric layer 120 is disposed on top of and in physical contact with the semiconductor layer 130, such that the dielectric layer 120 is sandwiched between and in physical contact with both the first contact layer 110 and the semiconductor layer 130; wherein the dielectric layer 120 suppresses photoemission of carriers between the first contact layer 110 and the semiconductor layer 130 under incident light.

[0098] In some examples, the dielectric layer 120 allows a first carrier type to exit the semiconductor layer 130 and be collected at the first contact layer 110, while blocking transport of a second carrier type from the first contact layer 110, wherein when the first carrier type is a hole the second carrier type is an electron and when the first carrier type is an electron the second carrier type is a hole.

[0099] In some examples, the dielectric layer 120 allows holes to exit the semiconductor layer 130 and be collected at the first contact layer 110.

[0100] In some examples, the device 100 has a positive conduction band offset and a negative valence band offset.

[0101] In some examples, the device 100 has a positive valence band offset.

[0102] The first contact layer 110 can comprise any suitable material, such as those known in the art. In some examples, the first contact layer 110 comprises a first metal. In some examples, the first contact layer 110 comprises a first metal selected from the group consisting of Au, Pt, Pd, Ni, Mo, Cr, W, Zr, Pb, Ag, Al, Ti, Bi, or a combination thereof. In some examples, the first contact layer 110 comprises a first metal selected from the group consisting of Pt, Ni, or a combination thereof. In some examples, the first contact layer 110 comprises Pt.

[0103] In some examples, the first contact layer 110 comprises a first electrode.

[0104] Referring now to Figure 29, in some examples, the first contact layer 110 comprises a first portion 110a and a second portion 110b, the first portion 110a being a cathode and the second portion 110b being an anode.

[0105] Referring now to Figure 30, in some examples, the dielectric layer 120 comprises a first portion 120a with a first thickness and a second portion 120b with a second thickness, the first portion 120a being in contact with the cathode and the second portion 120b being in contact with the anode, wherein the first thickness and the second thickness can be the same or different.

[0106] Referring now to Figure 31, in some examples, the dielectric layer 120 further comprises a third portion 120c with a third thickness, the third portion 120c extending from the first portion 120a to the second portion 120b, wherein the third thickness can be the same or different than the first thickness and / or the second thickness.

[0107] Referring now to Figure 32 - Figure 35, in some examples, the devices 100 further comprise a second contact layer 140, wherein the semiconductor layer 130 is disposed on top of and in physical contact with the second contact layer 140, such that the semiconductor layer 130 is sandwiched between and in physical contact with the dielectric layer 120 and the second contact layer 140.

[0108] The second contact layer 140 can comprise any suitable material, such as those known in the art. In some examples, the second contact layer 140 comprises a second metal. In some examples, the second contact layer 140 comprises a second metal selected from the group consisting of Au, Pt, Pd, Ni, Mo, Cr, W, Zr, Pb, Ag, Al, Ti, Bi, or a combination thereof. In some examples, the second contact layer 140 comprises a second metal selected from the group consisting of Ti, Au, or a combination thereof.

[0109] In some examples, the second contact layer 140 comprises a second electrode.

[0110] The first contact layer 110 and / or the second contact layer 140 can have an average thickness of 100 nanometers (nm) or less (e.g., 95 nm or less, 90 nm or less, 85 nm or less, 80 nm or less, 75 nm or less, 70 nm or less, 65 nm or less, 60 nm or less, 55 nm or less, 50 nm or less, 45 nm or less, 40 nm or less, 35 nm or less, 30 nm or less, 25 nm or less, 20 nm or less, 15 nm or less, 10 nm or less, 5 or nm or less). In some examples, the first contact layer 110 and / or the second contact layer 140 can have an average thickness of 1 nm or more (e.g., 5 nm or more,

[0111] 10 nm or more, 15 nm or more, 20 nm or more, 25 nm or more, 30 nm or more, 35 nm or more,

[0112] 40 nm or more, 45 nm or more, 50 nm or more, 55 nm or more, 60 nm or more, 65 nm or more,

[0113] 70 nm or more, 75 nm or more, 80 nm or more, 85 nm or more, 90 nm or more, or 95 nm or more). The average thickness of the first contact layer 110 and / or the second contact layer 140 can independently range from any of the minimum values described above to any of the maximum values described above. For example, the first contact layer 110 and / or the second contact layer 140 can each independently have an average thickness of from 1 nm to 100 nm (e.g., from 1 to 90 nm, from 1 to 80 nm, from 1 to 70 nm, from 1 to 60 nm, or from 1 to 50 nm).

[0114] The semiconductor layer 130 can comprise any suitable material, such as those known in the art. In some examples, the semiconductor material comprises In some examples, the semiconductor material comprises Ga2Ch, (Al,Ga)2Ch, SiC, (Al,Ga)N, GaN, diamond, Ge2O, or a combination thereof. In some examples, the semiconductor material comprises the pseudo binary alloy (Al,Ga)2O3, or SiC, or (Al,Ga)N to enable band-to-band absorption and photo response in the ultraviolet range. In some examples, the semiconductor material comprises Ga2O3.

[0115] In some examples, the semiconductor layer 130 further comprises a dopant.

[0116] In some examples, the semiconductor layer 130 can have an average thickness of 1 nanometer (nm) or more (e.g., 2 nm or more, 3 nm or more, 4 nm or more, 5 nm or more, 6 nm or more, 7 nm or more, 8 nm or more, 9 nm or more, 10 nm or more, 15 nm or more, 20 nm or more, 25 nm or more, 30 nm or more, 35 nm or more, 40 nm or more, 45 nm or more, 50 nm or more, 60 nm or more, 70 nm or more, 80 nm or more, 90 nm or more, 100 nm or more, 125 nm or more, 150 nm or more, 175 nm or more, 200 nm or more, 225 nm or more, 250 nm or more, 300 nm or more, 350 nm or more, 400 nm or more, 450 nm or more, 500 nm or more, 600 nm or more, 700 nm or more, 800 nm or more, 900 nm or more, 1 micrometer (pm, micron) or more, 1.25 pm or more, 1.5 pm or more, 1.75 pm or more, 2 pm or more, 2.25 pm or more, 2.5 pm or more, 3 pm or more, 3.5 pm or more, 4 pm or more, 4.5 pm or more, 5 pm or more, 6 pm or more, 7 pm or more, 8 pm or more, 9 pm or more, 10 pm or more, 15 pm or more, 20 pm or more, 25 pm or more, 30 pm or more, 35 pm or more, 40 pm or more, 45 pm or more, 50 pm or more, 60 pm or more, 70 pm or more, 80 pm or more, or 90 pm or more). In some examples, In some examples, the semiconductor layer 130 can have an average thickness of 100 micrometers (microns, pm) or less (e.g., 90 pm or less, 80 pm or less, 70 pm or less, 60 pm or less, 50 pm or less, 45 pm or less, 40 pm or less, 35 pm or less, 30 pm or less, 25 pm or less, 20 pm or less, 15 pm or less, 10 pm or less, 9 pm or less, 8 pm or less, 7 pm or less, 6 pm or less, 5 pm or less, 4.5 pm or less, 4 pm or less, 3.5 pm or less, 3 pm or less, 2.5 pm or less, 2.25 pm or less, 2 pm or less, 1.75 pm or less, 1.5 pm or less, 1.25 pm or less, 1 pm or less, 900 nm or less, 800 nm or less, 700 nm or less, 600 nm or less, 500 nm or less, 450 nm or less, 400 nm or less, 350 nm or less, 300 nm or less, 250 nm or less, 225 nm or less, 200 nm or less, 175 nm or less, 150 nm or less, 125 nm or less, 100 nm or less, 90 nm or less, 80 nm or less, 70 nm or less, 60 nm or less, 50 nm or less, 45 nm or less, 40 nm or less, 35 nm or less, 30 nm or less, 25 nm or less, 20 nm or less, 15 nm or less, 10 nm or less, 9 nm or less, 8 nm or less, 7 nm or less, 6 nm or less, 5 nm or less, 4 nm or less, 3 nm or less, or 2 nm or less). The average thickness of the semiconductor layer 130 can range from any of the minimum values described above to any of the maximum values described above. For example, the semiconductor layer 130 can have an average thickness of from 1 nm to 100 pm (e.g., from 1 nm to 50 pm, from 50 pm to 100 pm, from 1 nm to 10 nm, from 10 nm to 100 nm, from 100 nm to 1 pm, from 1 pm to 10 pm, from 10 pm to 100 pm, from 1 nm to 75 pm, from 1 nm to 25 pm, or from 1 nm to 10 pm). In some examples, the semiconductor layer 130 has an average thickness of from 1 nm to 10 pm. The average thickness of the can be measured using methods known in the art, such as, for example, atomic force microscopy or electron microscopy.

[0117] Referring now to Figure 36 and Figure 37, in some examples, the semiconductor layer 130 comprises a first portion 130a comprising a first semiconductor material and a second portion 130b comprising a second semiconductor material, the first portion 130a being disposed on top of the second portion 130b, such that the first portion 130a is sandwiched between and in physical contact with both the dielectric layer 120 and the second portion 130b. In some examples, the first portion 130a has a first thickness and the second portion 130b has a second thickness, the first thickness and the second thickness being the same or different. In some examples, the first semiconductor material and the second semiconductor material are different. In some examples, the first semiconductor material further comprises a first dopant in a first concentration; the second semiconductor material further comprises a second dopant in a second concentration; or a combination thereof. In some examples, the first semiconductor material and the second semiconductor material are different, the first dopant and the second dopant are different, the first concentration and the second concentration are different, or a combination thereof. In some examples, the first semiconductor material and the second semiconductor material are the same.

[0118] The dielectric layer 120 can comprise any suitable material, such as those known in the art. In some examples, the dielectric material comprises a high-K dielectric material.

[0119] In some examples, the dielectric material comprises hafnium silicate, zirconium silicate, hafnium oxide, barium titanate, barium-strontium titanate, zirconium dioxide, titanium dioxide, silicon nitride, aluminum oxide, aluminum nitride, magnesium oxide, or a combination thereof.

[0120] In some examples, the dielectric material comprises (BaxSri-x)TiO3, where x is from 0 to 1. For example, x can be 0 or more (e.g., 0.05 or more, 0.1 or more, 0.15 or more, 0.2 or more, 0.25 or more, 0.3 or more, 0.35 or more, 0.4 or more, 0.45 or more, 0.5 or more, 0.55 or more, 0.6 or more, 0.65 or more, 0.7 or more, 0.75 or more, 0.8 or more, 0.85 or more, 0.9 or more, or 0.95 or more). In some examples, x can be 1 or less (e.g., 0.95 or less, 0.9 or less, 0.85 or less, 0.8 or less, 0.75 or less, 0.7 or less, 0.65 or less, 0.6 or less, 0.65 or less, 0.5 or less, 0.55 or less, 0.4 or less, 0.45 or less, 0.3 or less, 0.35 or less, 0.2 or less, 0.25 or less, or 0.1 or less). The value of x can range from any of the minimum values described above to any of the maximum values described above. For example, x can be from 0 to 1 (e.g., from 0 to 0.5, from 0.5 to 1, from 0 to 0.2, from 0.2 to 0.4, from 0.4 to 0.6, from 0.6 to 0.8, from 0.8 to 1, from 0 to 0.95, from 0 to 0.9, from 0 to 0.85, from 0 to 0.8, from 0 to 0.75, from 0 to 0.7, from 0 to 0.65, from 0 to 0.6, from 0 to 0.55, from 0 to 0.5, from 0 to 0.45, from 0 to 0.4, from 0 to 0.35, from 0 to 0.3, from 0 to 0.25, from 0 to 0.2, from 0 to 0.15, from 0 to 0.1, from 0.1 to 1, from 0.15 to 1, from 0.2 to 1, from 0.25 to 1, from 0.3 to 1, from 0.35 to 1, from 0.4 to 1, from 0.45 to 1, from 0.5 to 1, from 0.55 to 1, from 0.6 to 1, from 0.65 to 1, from 0.7 to 1, from 0.75 to 1, from 0.8 to 1, from 0.85 to 1, from 0.9 to 1, from 0.1 to 0.9, from 0.2 to 0.8, from 0.3 to 0.7, or from 0.4 to 0.6).

[0121] In some examples, the dielectric material comprises BaTiCh.

[0122] In some examples, the semiconductor material comprises Ga2Ch and the dielectric material comprises BaTiCh.

[0123] In some examples, the dielectric layer 120 has an average thickness of 2 nanometers (nm) or more (e.g., 3 nm or more, 4 nm or more, 5 nm or more, 6 nm or more, 7 nm or more, 8 nm or more, 9 nm or more, 10 nm or more, 15 nm or more, 20 nm or more, 25 nm or more, 30 nm or more, 35 nm or more, 40 nm or more, 45 nm or more, 50 nm or more, 55 nm or more, 60 nm or more, 65 nm or more, 70 nm or more, 75 nm or more, 80 nm or more, 85 nm or more, or 90 nm or more). In some examples, the dielectric layer 120 has an average thickness of 100 nm or less (e.g., 95 nm or less, 90 nm or less, 85 nm or less, 80 nm or less, 75 nm or less, 70 nm or less, 65 nm or less, 60 nm or less, 55 nm or less, 50 nm or less, 45 nm or less, 40 nm or less, 35 nm or less, 30 nm or less, 25 nm or less, 20 nm or less, 15 nm or less, 10 nm or less, 9 nm or less, 8 nm or less, 7 nm or less, 6 nm or less, or 5 nm or less). The average thickness of the dielectric layer 120 can range from any of the minimum values described above to any of the maximum values described above. For example, the dielectric layer 120 can have an average thickness of from 2 to 100 nanometers (nm) (e.g., from 2 nm to 50 nm, from 50 nm to 100 nm, from 2 nm to 25 nm, from 25 nm to 50 nm, from 50 nm to 75 nm, from 75 nm to 100 nm, from 2 nm to 80 nm, from 2 nm to 60 nm, from 2 nm to 40 nm, from 2 nm to 20 nm, or from 2 nm to 10 nm). In some examples, the dielectric layer 120 can have an average thickness of from 2 to 20 nm. In some examples, the dielectric layer 120 can have an average thickness of from 2 to 10 nm. The average thickness of the can be measured using methods known in the art, such as, for example, atomic force microscopy or electron microscopy.

[0124] In some examples, the dielectric layer 120 comprises two or more dielectric materials, wherein each of the two or more dielectric materials is selected to further suppress the photoemission of carriers between the first contact layer 110 and the semiconductor.

[0125] Referring now to Figure 38 and Figure 39, in some examples, the dielectric layer 120 comprises a first layer 122 comprising a first dielectric material and a second layer 124 comprising a second dielectric material, the first layer 122 being disposed on top of the second layer 124, such that the first layer 122 is sandwiched between and in physical contact with both the first contact layer 110 and the second layer 124, and the second layer 124 is sandwiched between and in physical contact with the first layer 122 and the semiconductor layer 130. In some examples, the first layer 122 has a first thickness and the second layer 124 has a second thickness, the first thickness and the second thickness being the same or different. In some examples, the first dielectric material and the second dielectric material are different. In some examples, the first dielectric material comprises BaTiCh and the second dielectric material comprises AI2O3, AIN, or a combination thereof.

[0126] Referring now to Figure 40 and Figure 41, in some examples, the semiconductor layer 130 comprises a first portion 130a comprising a first semiconductor material and a second portion 130b comprising a second semiconductor material; and the dielectric layer 120 comprises a first layer 122 comprising a first dielectric material and a second layer 124 comprising a second dielectric material; the first layer 122 is disposed on top of and in physical contact with the second layer 124, such that the first layer 122 is sandwiched between and in physical contact with the first contact layer 110 and the second layer 124; and the first portion 130a is disposed on top of and in physical contact with the second portion 130b, such that the first portion 130a is sandwiched between and in physical contact with the second layer 124 and the second portion 130b.

[0127] In some examples, the device 100 can comprise a solar blind photodetection device.

[0128] In some examples, the device 100 exhibits a UV-Vis rejection ratio that is higher than the UV-Vis rejection ratio for a comparable device in the absence of the dielectric layer 120.

[0129] In some examples, the device exhibits a UV-Vis rejection ratio of 1 x 103or more (e.g., 5 x 103or more, 1 x 104or more, 5 x 104or more, 1 x 105or more, 5 x 105or more, 1 x 106or more, 5 x 106or more, 1x107or more, 5 x 107or more, 1x108or more, 5 x 108or more, 1x109or more, or 5 x 109or more). In some examples, the device exhibits a UV-Vis rejection ratio of 1 x io10or less (e.g., 5 x 109or less, 1x109or less, 5 x 108or less, 1x108or less, 5 x 107or less, 1 x 107or less, 5 x 106or less, 1x106or less, 5 x 105or less, 1x105or less, 5 x 104or less, 1 x 104or less, or 5 x 103or less). The UV-Vis rejection ratio of the device can range from any of the minimum values described above to any of the maximum values described above. For example, the device can exhibit a UV-Vis rejection ratio of from 1 x io3to 1xio10(e.g., from 1 x 103to 5 x 107, from 5 x 107to 1x1010, from 1 x 103to 1x105, from 1 x 105to 1x107, from 1 x IQ7to 1 x 1010, from 1 x IQ3to 5 x IQ9, from 5 x IQ3to 1xIQ10, from 5 x IQ3to 1xIQ10, from 1 x 104to 1xIO10, from 1 x 105to 1xIO10, from 1 x 106to 1xIO10, or from 1 x 108to 1 x IO10).

[0130] Also disclosed herein are solar blind photodetection devices comprising a dielectric layer 120 comprising BaTiCh disposed on and in physical contact with a semiconductor layer 130 comprising Ga2Ch. In some examples, the solar blind photodetection device can comprise any of the devices disclosed herein.

[0131] The devices 100 are not limited to the precise arrangements shown in Figure 28 - Figure 41, and the drawings are not necessarily drawn to scale. For example, the dimensions (e.g., length, width, height) of each individual layer can vary and may be the same or different than any of the other layers.

[0132] In some examples, the devices 100 can further include one or more trenches, for example for field termination.

[0133] Methods of Making

[0134] Also disclosed herein are methods of making any of the devices 100 disclosed herein. For example, the method can comprise depositing, in any order, the first contact layer 110, the semiconductor layer 130, the dielectric layer 120, and the second contact layer 140 (when present).

[0135] In some examples, depositing the first contact layer 110, the semiconductor layer 130, the dielectric layer 120, and / or the second contact layer 140 (when present) each independently comprises electroplating, lithographic deposition, electron beam deposition, thermal deposition, spin coating, drop-casting, zone casting, dip coating, blade coating, spraying, vacuum filtration, chemical vapor deposition (CVD), atomic layer deposition (ALD), physical vapor deposition (PVD), sputtering, pulsed laser deposition, molecular beam epitaxy, evaporation (e.g., thermal evaporation), three-dimensional (3D) particle printing such as aerosol jet printing, metalorganic chemical vapor deposition (MOCVD), molecular beam epitaxy (MBE), pulsed laser deposition (PLD), Hydride Vapor Phase Epitaxy (HVPE), melt growth, or a combination thereof.

[0136] In some examples, the methods can further comprise etching, such as reactive ion etching. For example, the methods can further comprise etching to form trenches, for example for field termination.

[0137] Methods of Use

[0138] Also disclosed herein are methods of use of any of the devices 100 disclosed herein. For example, the methods can comprise using the device 100 as a solar blind photodetector.

[0139] Also disclosed herein are methods of use of any of the solar blind photodetectors disclosed herein. For example, the methods can comprise using the solar blind photodetector for medical imaging, fire detection, photonic communication, defense application, or a combination thereof.

[0140] A number of embodiments of the invention have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the invention. Accordingly, other embodiments are within the scope of the following claims.

[0141] The examples below are intended to further illustrate certain aspects of the devices and methods described herein, and are not intended to limit the scope of the claims.

[0142] EXAMPLES

[0143] The following examples are set forth below to illustrate the methods and results according to the disclosed subject matter. These examples are not intended to be inclusive of all aspects of the subject matter disclosed herein, but rather to illustrate representative methods and results. These examples are not intended to exclude equivalents and variations of the present invention which are apparent to one skilled in the art.

[0144] Efforts have been made to ensure accuracy with respect to numbers (e.g., amounts, temperature, etc.) but some errors and deviations should be accounted for. Unless indicated otherwise, parts are parts by weight, temperature is in °C or is at ambient temperature, and pressure is at or near atmospheric. There are numerous variations and combinations of measurement conditions, e.g., component concentrations, temperatures, pressures and other measurement ranges and conditions that can be used to optimize the described process.

[0145] Example 1 - High-K Dielectric barriers to suppress internal photoemission and photocurrents

[0146] UV solar-blind photodetectors have applications in many areas of industry, from medical imaging, fire detection, photonic communication, and various defense related applications. Solid state photodetectors have advantages over the incumbent technology - photomultiplier tubes — in that they are more robust and easier to integrate. Ultra-wide bandgap materials are excellent candidates for UV Solar blind photodetectors in that they do not require the complex optical filters required to make a solar blind UV photodetector out of lower bandgap materials like silicon. Ga2Ch specifically is an ideal candidate for solar blind detection (4.4 eV- 6.2 eV) due to its absorption cut-off at 4.8 eV. Unfortunately, many Ga2Os detectors have very low UV-Visible rejection ratios. Here, a structure is presented that increases the UV-visible rejection ratio by integrating a thin layer of the high-K dielectric BaTiCh on top of Ga2Ch, increasing the UV- Visible rejection ratio by five orders of magnitude. Beginning with 10 gm of HVPE grown (001) Ga2Os, the surface was etched to produce trenches of various depths. Following this, 10 nm of BaTiOs was sputtered conformally onto the surface. Top contacts of Pt and bottom contacts composed of a bilayer of 30 nm Ti and 70 nm Au were thermally evaporated. The final structure can be seen in Figure 1. For comparison, a sample was also fabricated using the same steps save the BaTiCh deposition. This structure can be seen in Figure 2. The devices then underwent IV testing in both light and dark conditions (Figure 3), and spectral response testing (Figure 4).

[0147] Example 2

[0148] Described herein are photodetectors comprising: I. A suitably doped semiconductor layer, II. A dielectric of thickness (2 nm - 100 nm) deposited on this layer, III. A contact material, such as metal, (thickness < 50 nm) deposited on top of the dielectric, and IV. A metal contact metal deposited to make contact to the doped semiconductor layer, where the dielectric layer suppresses the photoemission of carriers from the metal to the semiconductor, or semiconductor to the metal under incident light.

[0149] In some examples, the dielectric comprises BaTiCh, or (Ba,Sr)TiO3, with the thickness of the dielectric being 2 nm - 100 nm.

[0150] In some examples, the semiconducting material comprises the pseudo binary alloy (Al,Ga)2Ch, or SiC, or (Al,Ga)N to enable band-to-band absorption and photo response in the ultraviolet range.

[0151] Also disclosed herein are photodetectors comprising: I. A suitably doped semiconductor layer, II. A dielectric of thickness (2 nm - 100 nm) deposited on this layer, and III. A contact material, such as metal, (thickness < 50 nm) deposited on top of the dielectric to create contacts that serve as anode and cathode, where the dielectric layer suppresses the photoemission of carriers from the metal to the semiconductor, or semiconductor to the metal under incident light.

[0152] In some examples, the thickness of the dielectric may be different under the anode and cathode metal, and in the region between these.

[0153] In some examples, the dielectric may be a single dielectric layer or a composite of two or more dielectrics selected in such a way that the photoemission of carriers from metal to semiconductor, or semiconductor to metal is suppressed.

[0154] Also disclosed herein are structures including a layer of BaTiOs contacting a layer of semiconducting Ga2Ch used for solar blind photodetection.

[0155] Example 3

[0156] Next, the inclusion of a high-k dielectric will be discussed. Options for High-k dielectrics include hafnium silicate (HfSiO4) (Eg > 6), zirconium silicate, hafnium oxide (k: 25, Eg: 2.8), barium titanate (k: 40, Eg: 3.2), zirconium dioxide (k: 25, Eg: 5.8), titanium oxide (k: 80, Eg: 3.5), and silicon nitride (SisN4) (k: 7, Eg: 5.3). Aluminum oxide (AI2O3) can also be considered.

[0157] Dielectrics were investigated for the structure shown schematically in Figure 5. The charge alignment with Ga2Ch is summarized in Table 1.

[0158] Table 1. Charge alignment with Ga2Ch.

[0159] Flat band voltage diagrams of devices including AI2O3 (k: 9), TiCh (k: 80), and BaTiCh (k: 40) are shown schematically in Figure 6 - Figure 8, respectively.

[0160] Example 4 - Development of Ga2Os Solar Blind UV Avalanche Photodetectors

[0161] The solar spectrum at sea level includes very little radiation below 280 nm (Figure 10). “Solar Blind” refers to the section of the electromagnetic (EM) spectrum emitted by the sun that gets filtered out by the ozone in the atmosphere, generally about 280 to 200 nm (Figure 9).

[0162] Applications of UV photodetectors include, but are not limited to, chromatography, medical imaging, fire detection, defense, and communications.

[0163] Advantages of Ga2O3 include, but are not limited to, absorption cut off at -280 nm, robust design, high temperature operation, and radiation hardness. B-Ga2O3 begins to absorb at -280 nm, making it a good candidate for a solar-blind UV photodetector.

[0164] Current UV detection systems include, but are not limited to, Si based avalanche photo detectors (APDs) and photomultiplier tubes. These are large and / or delicate. Solid state- UV detection without optical filtration is desirable. There are two general types of photodetectors: metal-semiconductor-metal (MSM); and P-N junction. In most UWBG material systems, there is no p-type material, so a PN junction is not ideal. By using a heterostructure, a P-N junction can be achieved, but the interface defects detract from device performance. MSM devices have low dark current and are easy to manufacture, but they suffer from low UV-vis rejection ratios due to photoemitted carriers being excited into the semiconductor from the metal. By including a dielectric layer between the metal and semiconductor, the photoemitted carriers are suppressed, and the dark current is lowered. Issues with dielectric integration include: 1) absorption by dielectric must be prevented, 2) holes must be extracted, 3) electric field must be high enough for a long enough distance to induce avalanche, and 4) EVB tunneling must be prevented, as shown schematically in Figure 11.

[0165] For example, the band diagram of a Ni / BaTiO3 / Ga2O3 heterostructure shows an increased barrier to electrons (Figure 13).

[0166] An example device design is shown in Figure 14 (Sn-doped Ga2O3, Nd = 5 * 1018cm'3).

[0167] The fabrication of the 10 pm HVPE Ga2O3 / BaTiO3 trench structure is shown schematically in Figure 15 and Figure 16. The fabrication comprises: 1) Deposition of 10 pm HVPE Ga2O3 on a wafer ([(001) oriented], Novel Crystal Technology, Inc.); 2) ICP-RIE etch edge termination (3 pm and / or 6 pm); 3) RF sputter 10 nm of BaTiOs conformally; and 4) evaporate top and bottom metal contacts.

[0168] The responsivity (Figure 17) and light and dark IV curves (Figure 18) of the 10 pm HVPE Ga2O3 / BaTiO3 trench structures were tested. The performance values of the 10 pm HVPE Ga2O3 / BaTiO3 trench structures are summarized in Table 2. Holes were extracted across the Ga2O3 / BaTiO3 junction. The device showed excellent dark current and UV / Vis rejection ratio.

[0169] Table 2. Performance values. |

[0170] Next, the devices were investigated to determine if there was absorption from BaTiCh. The optical set-up included:

[0171] - D2 lamp

[0172] - Light source fiber coupled with 50 micron fiber;

[0173] Columnated using 10 mm focal length OAP mirror;

[0174] Iris used to reduce beam size to 5 mm;

[0175] Columnated light focused into sp2155 spectrometer using 100 mm OAP;

[0176] - PIXIS 400 CCD used at 0.4 s exposure, almost closed slit;

[0177] Stitching errors averaged by overlapping spectra by 50 nm. The photodetector absorption in shown in Figure 19, the cut-off is ~4.6 eV. The BaTiCh absorption is shown in Figure 20, cut-off is ~3.15 eV. If current density (at 0 V) is proportional to absorption (JPh oc a), the results in Figure 19 and Figure 20 show that the absorption is due to Ga2Ch, not the BaTiCh.

[0178] A schematic Illustration of a second generation device design is shown in Figure 21 including 1 pm MOCVD Ga2O3 / BaTiO3 and a platinum top contact instead of nickel. The equilibrium band diagram for the device is shown in Figure 22.

[0179] Fabrication of 1 pm MOCVD Ga2O3 / BaTiO3 device is shown schematically in Figure 23. The fabrication comprises: 1) use of a Sn-doped Ga2O3 (010) wafer (Novel Crystal Technology, Inc.); 2) growth of 1 pm Ga2O3 (Nd = 1 * 1016cm'3) via MOCVD; 3) sputter 10 nm of BaTiOs; 4) thermally evaporate contact metals; and 5) ICP-RIE etch 1.5 pm trenches. The etch parameters are summarized in Table 3.

[0180] Table 3. Etch parameters.

[0181] The responsivity (Figure 24) and light and dark IV curves (Figure 25) of the 1 pm MOCVD Ga2O3 / BaTiO3 structure were tested. The performance values of the 1 pm MOCVD Ga2O3 / BaTiO3 structure are summarized in Table 4.

[0182] Table 4. Performance values of the 1 pm MOCVD Ga2O3 / BaTiO3 / Pt structure.

[0183] Analysis of the gain mechanism according to: 00 indicated that the peak value for gain was 138 at -50 V (Figure 26). The observed gain is likely due to photoconductive gain, not avalanche multiplication. Noise signature analysis and IV-T measurements can confirm the gain mechanism.

[0184] A comparison of the results for the 10 pm HVPE Ga2O3 / BaTiO3 trench structure (Figure 14) and the 1 pm MOCVD Ga2O3 / BaTiO3 structure (Figure 21) is shown in Table 5.

[0185] Table 5. Performance values of 10 pm HVPE Ga2O3 / BaTiO3 trench structure and the 1 pm MOCVD Ga2O3 / BaTiO3 structure.

[0186] The results herein indicate that progress has been made towards realizing a solar-blind Ga2O3 photodetector.

[0187] Example 5

[0188] The devices described herein achieve a high UV-Visible rejection ratio by employing a structure that blocks photoemitted electrons from entering the Ga2O3 while still allowing holes to exit the semiconductor and be collected at the contact. To state it another way, there must be a positive conduction band offset and a negative (or very small) valence band offset. Examples of dielectric materials that fulfill these requirements are BaTiCh and MgO (Figure 27A and Figure 27B, respectively), while a dielectric material that does not fulfill these requirements is SiCh (Figure 27C).

[0189] EXEMPLARY ASPECTS

[0190] In view of the described compositions, devices, systems, and methods, herein below are described certain more particularly described aspects of the inventions. The particularly recited aspects should not, however, be interpreted to have any limiting effect on any different claims containing different or more general teachings described herein or that the “particular” aspects are somehow limited in some way other than the inherent meanings of the language and formulas literally used therein.

[0191] Example 1 : A device comprising: a first contact layer; a semiconductor layer comprising a semiconductor material having a first bandgap; and a dielectric layer comprising a dielectric material; wherein the first contact layer is disposed on top of and in physical contact with the dielectric layer, and the dielectric layer is disposed on top of and in physical contact with the semiconductor layer, such that the dielectric layer is sandwiched between and in physical contact with both the first contact layer and the semiconductor layer; wherein the dielectric layer suppresses photoemission of carriers between the first contact layer and the semiconductor layer under incident light.

[0192] Example 2: The device of any examples herein, particularly example 1, wherein the dielectric layer allows holes to exit the semiconductor layer and be collected at the first contact layer.

[0193] Example 3 : The device of any examples herein, particularly example 1 or example 2, wherein the device has a positive conduction band offset and a negative valence band offset.

[0194] Example 4: The device of any examples herein, particularly examples 1-3, wherein the first contact layer comprises a first metal.

[0195] Example 5: The device of any examples herein, particularly example 4, wherein the first metal comprises Ni, Pt, or a combination thereof.

[0196] Example 6: The device of any examples herein, particularly example 4 or example 5, wherein the first metal comprises Pt.

[0197] Example 7: The device of any examples herein, particularly examples 1-6, wherein the first contact layer comprises a first electrode.

[0198] Example 8: The device of any examples herein, particularly examples 1-7, wherein the first contact layer comprises a first portion and a second portion, the first portion being a cathode and the second portion being an anode.

[0199] Example 9: The device of any examples herein, particularly example 8, wherein the dielectric layer comprises a first portion with a first thickness and a second portion with a second thickness, the first portion being in contact with the cathode and the second portion being in contact with the anode, wherein the first thickness and the second thickness can be the same or different.

[0200] Example 10: The device of any examples herein, particularly example 9, wherein the dielectric layer further comprises a third portion with a third thickness, the third portion extending from the first portion to the second portion, wherein the third thickness can be the same or different than the first thickness and / or the second thickness.

[0201] Example 11 : The device of any examples herein, particularly examples 1-10, further comprising a second contact layer, wherein the semiconductor layer is disposed on top of and in physical contact with the second contact layer such that the semiconductor layer is sandwiched between and in physical contact with the dielectric layer and the second contact layer.

[0202] Example 12: The device of any examples herein, particularly example 11, wherein the second contact layer comprises a second metal.

[0203] Example 13: The device of any examples herein, particularly example 12, wherein the second metal comprises Ti, Au, or a combination thereof.

[0204] Example 14: The device of any examples herein, particularly examples 11-13, wherein the second contact layer comprises a second electrode.

[0205] Example 15: The device of any examples herein, particularly examples 1-14, wherein the first contact layer and / or the second contact layer (when present) has an average thickness of 100 nanometers (nm) or less, or 50 nanometers (nm) or less.

[0206] Example 16: The device of any examples herein, particularly examples 1-15, wherein the semiconductor layer further comprises a dopant.

[0207] Example 17: The device of any examples herein, particularly examples 1-16, wherein the semiconductor material comprises Ga2Ch, (Al,Ga)2Ch, SiC, (Al,Ga)N, GaN, diamond, Ge2O, or a combination thereof.

[0208] Example 18: The device of any examples herein, particularly examples 1-17, wherein the semiconductor material comprises the pseudo binary alloy (Al,Ga)2Ch, or SiC, or (Al,Ga)N to enable band-to-band absorption and photo response in the ultraviolet range.

[0209] Example 19: The device of any examples herein, particularly examples 1-18, wherein the semiconductor layer has an average thickness of from 1 nm to 100 pm, such as from 1 nm to 10 pm.

[0210] Example 20: The device of any examples herein, particularly examples 1-19, wherein the semiconductor layer comprises a first portion comprising a first semiconductor material and a second portion comprising a second semiconductor material, the first portion being disposed on top of the second portion, such that the first portion is sandwiched between and in physical contact with both the dielectric layer and the second portion.

[0211] Example 21 : The device of any examples herein, particularly example 20, wherein the first portion has a first thickness and the second portion has a second thickness, the first thickness and the second thickness being the same or different. Example 22: The device of any examples herein, particularly example 20 or example 21, wherein the first semiconductor material further comprises a first dopant in a first concentration; wherein the second semiconductor material further comprises a second dopant in a second concentration; or a combination thereof.

[0212] Example 23 : The device of any examples herein, particularly examples 20-22, wherein the first semiconductor material and the second semiconductor material are different, the first dopant and the second dopant are different, the first concentration and the second concentration are different, or a combination thereof.

[0213] Example 24: The device of any examples herein, particularly examples 20-23, wherein the first semiconductor material and the second semiconductor material are different.

[0214] Example 25: The device of any examples herein, particularly examples 20-23, wherein the first semiconductor material and the second semiconductor material are the same.

[0215] Example 26: The device of any examples herein, particularly examples 1-25, wherein the dielectric material comprises a high-K dielectric material.

[0216] Example 27: The device of any examples herein, particularly examples 1-26, wherein the dielectric material comprises hafnium silicate, zirconium silicate, hafnium oxide, barium titanate, barium-strontium titanate, zirconium dioxide, titanium dioxide, silicon nitride, aluminum oxide, aluminum nitride, magnesium oxide, or a combination thereof.

[0217] Example 28: The device of any examples herein, particularly examples 1-27, wherein the dielectric material comprises (BaxSri-x)TiO3, where x is from 0 to 1.

[0218] Example 29: The device of any examples herein, particularly examples 1-28, wherein the dielectric material comprises BaTiCh.

[0219] Example 30: The device of any examples herein, particularly examples 1-29, wherein the dielectric layer has an average thickness of from 2 to 100 nanometers (nm), such as from 2 to 20 nm, or from 2 nm to 10 nm.

[0220] Example 31 : The device of any examples herein, particularly examples 1-30, wherein the dielectric layer comprises two or more dielectric materials, wherein each of the two or more dielectric materials is selected to further suppress the photoemission of carriers between the first contact layer and the semiconductor.

[0221] Example 32: The device of any examples herein, particularly examples 1-31, wherein the dielectric layer comprises a first layer comprising a first dielectric material and a second layer comprising a second dielectric material, the first layer being disposed on top of the second layer, such that the first layer is sandwiched between and in physical contact with both the first contact layer and the second layer, and the second layer is sandwiched between and in physical contact with the first layer and the semiconductor layer.

[0222] Example 33: The device of any examples herein, particularly example 32, wherein the first layer has a first thickness and the second layer has a second thickness, the first thickness and the second thickness being the same or different.

[0223] Example 34: The device of any examples herein, particularly example 32 or example 33, wherein the first dielectric material and the second dielectric material are different.

[0224] Example 35: The device of any examples herein, particularly examples 32-34, wherein the first dielectric material comprises BaTiCh and the second dielectric material comprises AI2O3, AIN, or a combination thereof.

[0225] Example 36: The device of any examples herein, particularly examples 1-35, wherein: the semiconductor layer comprises a first portion comprising a first semiconductor material and a second portion comprising a second semiconductor material; and the dielectric layer comprises a first layer comprising a first dielectric material and a second layer comprising a second dielectric material; the first layer is disposed on top of and in physical contact with the second layer, such that the first layer is sandwiched between and in physical contact with the first contact layer and the second layer; and the first portion is disposed on top of and in physical contact with the second portion, such that the first portion is sandwiched between and in physical contact with the second layer and the second portion.

[0226] Example 37: The device of any examples herein, particularly examples 1-36, wherein the device comprises a solar blind photodetection device.

[0227] Example 38: The device of any examples herein, particularly examples 1-37, wherein the device exhibits a UV-Vis rejection ratio that is higher than the UV-Vis rejection ratio for a comparable device in the absence of the dielectric layer.

[0228] Example 39: The device of any examples herein, particularly examples 1-38, wherein the device exhibits a UV-Vis rejection ratio of 1 x 103to 1 x IO10.

[0229] Example 40: A method of making the device of any examples herein, particularly examples 1-39.

[0230] Example 41 : The method of any examples herein, particularly example 40, wherein the method comprises depositing, in any order, the first contact layer, the semiconductor layer, the dielectric layer, and the second contact layer (when present).

[0231] Example 42: A method of use of the device of any examples herein, particularly examples 1-39. Example 43 : The method of any examples herein, particularly example 42, wherein the method comprises using the device as a solar blind photodetector.

[0232] Example 44: A solar blind photodetection device comprising a dielectric layer comprising BaTiCh disposed on and in physical contact with a semiconductor layer comprising Ga2O3.

[0233] Example 45: A solar blind photodetection device comprising the device of any examples herein, particularly examples 1-39.

[0234] Example 46: A method of use of the solar blind photodetector of any examples herein, particularly example 44 or example 45, the method comprising using the solar blind photodetector for medical imaging, fire detection, photonic communication, defense application, or a combination thereof.

[0235] Other advantages which are obvious and which are inherent to the invention will be evident to one skilled in the art. It will be understood that certain features and sub-combinations are of utility and may be employed without reference to other features and sub-combinations. This is contemplated by and is within the scope of the claims. Since many possible embodiments may be made of the invention without departing from the scope thereof, it is to be understood that all matter herein set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.

[0236] The methods of the appended claims are not limited in scope by the specific methods described herein, which are intended as illustrations of a few aspects of the claims and any methods that are functionally equivalent are intended to fall within the scope of the claims. Various modifications of the methods in addition to those shown and described herein are intended to fall within the scope of the appended claims. Further, while only certain representative method steps disclosed herein are specifically described, other combinations of the method steps also are intended to fall within the scope of the appended claims, even if not specifically recited. Thus, a combination of steps, elements, components, or constituents may be explicitly mentioned herein or less, however, other combinations of steps, elements, components, and constituents are included, even though not explicitly stated.

Claims

CLAIMSWhat is claimed is:

1. A device comprising: a first contact layer; a semiconductor layer comprising a semiconductor material having a first bandgap; and a dielectric layer comprising a dielectric material; wherein the first contact layer is disposed on top of and in physical contact with the dielectric layer, and the dielectric layer is disposed on top of and in physical contact with the semiconductor layer, such that the dielectric layer is sandwiched between and in physical contact with both the first contact layer and the semiconductor layer; wherein the dielectric layer suppresses photoemission of carriers between the first contact layer and the semiconductor layer under incident light.

2. The device of claim 1, wherein the dielectric layer allows holes to exit the semiconductor layer and be collected at the first contact layer.

3. The device of claim 1 or claim 2, wherein the device has a positive conduction band offset and a negative valence band offset.

4. The device of any one of claims 1-3, wherein the first contact layer comprises a first metal.

5. The device of claim 4, wherein the first metal comprises Ni, Pt, or a combination thereof.

6. The device of claim 4 or claim 5, wherein the first metal comprises Pt.

7. The device of any one of claims 1-6, wherein the first contact layer comprises a first electrode.

8. The device of any one of claims 1-7, wherein the first contact layer comprises a first portion and a second portion, the first portion being a cathode and the second portion being an anode.

9. The device of claim 8, wherein the dielectric layer comprises a first portion with a first thickness and a second portion with a second thickness, the first portion being in contact with the cathode and the second portion being in contact with the anode, wherein the first thickness and the second thickness can be the same or different.

10. The device of claim 9, wherein the dielectric layer further comprises a third portion with a third thickness, the third portion extending from the first portion to the second portion, wherein the third thickness can be the same or different than the first thickness and / or the second thickness.

11. The device of any one of claims 1-10, further comprising a second contact layer, wherein the semiconductor layer is disposed on top of and in physical contact with the second contact layer such that the semiconductor layer is sandwiched between and in physical contact with the dielectric layer and the second contact layer.

12. The device of claim 11, wherein the second contact layer comprises a second metal.

13. The device of claim 12, wherein the second metal comprises Ti, Au, or a combination thereof.

14. The device of any one of claims 11-13, wherein the second contact layer comprises a second electrode.

15. The device of any one of claims 1-14, wherein the first contact layer and / or the second contact layer (when present) has an average thickness of 100 nanometers (nm) or less, or 50 nanometers (nm) or less.

16. The device of any one of claims 1-15, wherein the semiconductor layer further comprises a dopant.

17. The device of any one of claims 1-16, wherein the semiconductor material comprises Ga2Ch, (Al,Ga)2Ch, SiC, (Al,Ga)N, GaN, diamond, Ge2O, or a combination thereof.

18. The device of any one of claims 1-17, wherein the semiconductor material comprises the pseudo binary alloy (Al,Ga)2Ch, or SiC, or (Al,Ga)N to enable band-to-band absorption and photo response in the ultraviolet range.

19. The device of any one of claims 1-18, wherein the semiconductor layer has an average thickness of from 1 nm to 100 pm, such as from 1 nm to 10 pm.

20. The device of any one of claims 1-19, wherein the semiconductor layer comprises a first portion comprising a first semiconductor material and a second portion comprising a second semiconductor material, the first portion being disposed on top of the second portion, such thatthe first portion is sandwiched between and in physical contact with both the dielectric layer and the second portion.

21. The device of claim 20, wherein the first portion has a first thickness and the second portion has a second thickness, the first thickness and the second thickness being the same or different.

22. The device of claim 20 or claim 21, wherein the first semiconductor material further comprises a first dopant in a first concentration; wherein the second semiconductor material further comprises a second dopant in a second concentration; or a combination thereof.

23. The device of any one of claims 20-22, wherein the first semiconductor material and the second semiconductor material are different, the first dopant and the second dopant are different, the first concentration and the second concentration are different, or a combination thereof.

24. The device of any one of claims 20-23, wherein the first semiconductor material and the second semiconductor material are different.

25. The device of any one of claims 20-23, wherein the first semiconductor material and the second semiconductor material are the same.

26. The device of any one of claims 1-25, wherein the dielectric material comprises a high-K dielectric material.

27. The device of any one of claims 1-26, wherein the dielectric material comprises hafnium silicate, zirconium silicate, hafnium oxide, barium titanate, barium-strontium titanate, zirconium dioxide, titanium dioxide, silicon nitride, aluminum oxide, aluminum nitride, magnesium oxide, or a combination thereof.

28. The device of any one of claims 1-27, wherein the dielectric material comprises (BaxSn-x)TiO3, where x is from 0 to 1.

29. The device of any one of claims 1-28, wherein the dielectric material comprises BaTiCh.

30. The device of any one of claims 1-29, wherein the dielectric layer has an average thickness of from 2 to 100 nanometers (nm), such as from 2 to 20 nm, or from 2 nm to 10 nm.

31. The device of any one of claims 1-30, wherein the dielectric layer comprises two or more dielectric materials, wherein each of the two or more dielectric materials is selected to further suppress the photoemission of carriers between the first contact layer and the semiconductor.

32. The device of any one of claims 1-31, wherein the dielectric layer comprises a first layer comprising a first dielectric material and a second layer comprising a second dielectric material, the first layer being disposed on top of the second layer, such that the first layer is sandwiched between and in physical contact with both the first contact layer and the second layer, and the second layer is sandwiched between and in physical contact with the first layer and the semiconductor layer.

33. The device of claim 32, wherein the first layer has a first thickness and the second layer has a second thickness, the first thickness and the second thickness being the same or different.

34. The device of claim 32 or claim 33, wherein the first dielectric material and the second dielectric material are different.

35. The device of any one of claims 32-34, wherein the first dielectric material comprises BaTiCh and the second dielectric material comprises AI2O3, AIN, or a combination thereof.

36. The device of any one of claims 1-35, wherein: the semiconductor layer comprises a first portion comprising a first semiconductor material and a second portion comprising a second semiconductor material; and the dielectric layer comprises a first layer comprising a first dielectric material and a second layer comprising a second dielectric material; the first layer is disposed on top of and in physical contact with the second layer, such that the first layer is sandwiched between and in physical contact with the first contact layer and the second layer; and the first portion is disposed on top of and in physical contact with the second portion, such that the first portion is sandwiched between and in physical contact with the second layer and the second portion.

37. The device of any one of claims 1-36, wherein the device comprises a solar blind photodetection device.

38. The device of any one of claims 1-37, wherein the device exhibits a UV-Vis rejection ratio that is higher than the UV-Vis rejection ratio for a comparable device in the absence of the dielectric layer.

39. The device of any one of claims 1-38, wherein the device exhibits a UV-Vis rejection ratio of 1 x 103to 1 x IO10.

40. A method of making the device of any one of claims 1-39.

41. The method of claim 40, wherein the method comprises depositing, in any order, the first contact layer, the semiconductor layer, the dielectric layer, and the second contact layer (when present).

42. A method of use of the device of any one of claims 1-39.

43. The method of claim 42, wherein the method comprises using the device as a solar blind photodetector.

44. A solar blind photodetection device comprising a dielectric layer comprising BaTiCh disposed on and in physical contact with a semiconductor layer comprising Ga2Ch.

45. A solar blind photodetection device comprising the device of any one of claims 1-39.

46. A method of use of the solar blind photodetector of claim 44 or claim 45, the method comprising using the solar blind photodetector for medical imaging, fire detection, photonic communication, defense application, or a combination thereof.

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