MERCURY CADMIUM TELLURIDE-BLACK PHOSPHOROUS VAN DER WAALS HETEROJUNCTION INFRARED POLARIZATION DETECTOR AND PREPARATION METHOD THEREOF

Abstract

Disclosed are a mercury cadmium telluride-black phosphorus van der Waals heterojunction infrared polarization detector and a preparation method thereof. The structure of the detector from bottom to top comprises a substrate, a mercury cadmium telluride material, an insulating layer, a two-dimensional semiconductor black phosphorus, and metal electrodes. First, growing the mercury cadmium telluride material on the substrate, removing part of the mercury cadmium telluride by ultraviolet lithography and argon ion etching, filling with aluminum oxide as the insulating layer using an electron beam evaporation method, transferring the two-dimensional semiconductor material black phosphorus at the junction of mercury cadmium telluride and an insulating layer assisted by a polypropylene carbonate film, and preparing the metal source-drain electrodes by electron beam lithography technology combined with the lift-off process to form the mercury cadmium telluride-black phosphorus van der Waals heterojunction infrared polarization detector.

Claims

1. A mercury cadmium telluride-black phosphorus van der Waals heterojunction infrared polarization detector comprising: A substrate (1), a mercury cadmium telluride material (2) adjacent said substrate (1), said mercury cadmium telluride material (2) having a first side and a second side; an insulating layer (3) adjacent said second side of said mercury cadmium telluride material (2), a two-dimensional semiconductor material (4) contacting the mercury cadmium telluride material (2) and the insulating layer (3), a first metal electrode (5) on the first side of said mercury cadmium telluride material contacting the mercury cadmium telluride material (2), and a second metal electrode (6) contacting the insulating layer (3) and the two-dimensional semiconductor material (4), wherein, The insulating layer (3) covers a removed part of the mercury cadmium telluride material (2) with a thickness the same as that of the removed mercury cadmium telluride material (2).

2. A method for preparing a mercury cadmium telluride-black phosphorus van der Waals heterojunction infrared polarization detector comprising the following steps: 1) Preparing a mercury cadmium telluride material (2) on a substrate (1) by molecular beam epitaxy; 2) Forming a mask on the mercury cadmium telluride material (2) by ultraviolet lithography, removing a certain thickness of the mercury cadmium telluride material by argon ion etching, filling an insulating layer (3) by electron beam evaporation, and removing the mask using acetone soaking; 3) Using a mechanical exfoliation method to obtain a two-dimensional semiconductor material (4), transferring the two-dimensional semiconductor material to a silicon substrate, covering the two-dimensional semiconductor material with a polypropylene carbonate film, heating to make the polypropylene carbonate film have full contact with the two-dimensional semiconductor material, removing the polypropylene carbonate film from the silicon substrate after cooling, in which the two-dimensional semiconductor material is adsorbed, moving the polypropylene carbonate film under a microscope to align the two-dimensional semiconductor material with a junction of the mercury cadmium telluride material and aluminum oxide to form a sample, heating to make contact slowly, after cooling down, soaking the sample in acetone to completely dissolve the polypropylene carbonate film to obtain a mercury cadmium telluride-black phosphorus van der Waals heterojunction; 4) Preparing metal electrodes using electron beam lithography technology, combined with electron beam evaporation of metal and lift-off process to prepare a first metal electrode (5) in contact with the mercury cadmium telluride material and a second metal electrode (6) in contact with the two-dimensional semiconductor material.

3. The polarization detector according to claim 1 wherein: the substrate (1) is an intrinsic germanium substrate with a thickness of 0.9 mm.

4. The polarization detector according to claim 1 wherein: the mercury cadmium telluride material (2) is mercury cadmium telluride with a cut-off wavelength of 4.35 μm and a thickness of 8 μm.

5. The polarization detector according to claim 1 wherein: the insulating layer (3) is aluminum oxide with a thickness of 100-150 nm.

6. The polarization detector according to claim 1 wherein: the two-dimensional semiconductor material (4) is black phosphorus with a thickness of 50-150 nm.

7. The polarization detector according to claim 1 wherein: the first metal electrode (5) and the second metal electrode (6) are double-layer electrodes of titanium and gold.

8. The polarization detector according to claim 7 wherein: said double-layer electrodes of titanium and gold comprise a lower layer or titanium and an upper layer of gold; the thickness of the lower layer of titanium is 10-15 nm, and the thickness of the upper layer of gold is 35-45 nm.

9. The method according to claim 2 wherein: said first metal electrode and said second metal electrode are comprised of titanium and gold.

10. The method according to claim 2 wherein: a thickness of said titanium is 10-15 nm, and a thickness of said gold is 35-45 nm.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0030] FIG. 1 is a schematic cross-sectional view of the structure of a mercury cadmium telluride-black phosphorus van der Waals heterojunction infrared polarization detector. In the picture: 1 substrate, 2 mercury cadmium telluride material, 3 insulating layer, 4 two-dimensional semiconductor material, 5 metal electrode, 6 metal electrode.

[0031] FIG. 2 shows the photoresponse characteristics of a mercury cadmium telluride-black phosphorus van der Waals heterojunction infrared polarization detector; Wherein, FIG. 2 (a) shows the photoresponse characteristics of a mercury cadmium telluride-black phosphorus van der Waals heterojunction infrared polarization detector to a medium-wave infrared laser with a wavelength of 4324 nm under the condition of zero bias voltage; FIG. 2(b) shows the photoresponse characteristics of a mercury cadmium telluride-black phosphorus van der Waals heterojunction infrared polarization detector to a medium-wave infrared laser with a wavelength of 4135 nm under the condition of zero bias voltage; FIG. 2(c) shows the photoresponse characteristics of a mercury cadmium telluride-black phosphorus van der Waals heterojunction infrared polarization detector to a medium-wave infrared laser with a wavelength of 4034 nm under the condition of zero bias voltage;

[0032] FIG. 3 shows the relationship between the photocurrent generated by a mercury cadmium telluride-black phosphorus van der Waals heterojunction infrared polarization detector under the illumination of a laser with a wavelength of 4034 nm and the polarization angle of the incident light.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Example 1

[0033] The Example 1 of the present disclosure will be described in detail below with reference to the accompanying drawings:

[0034] The present disclosure develops a black phosphorus-mercury cadmium telluride mixed dimensional heterojunction infrared detector. By combining the traditional infrared photoelectric material mercury cadmium telluride and the emerging two-dimensional material black phosphorus to form a van der Waals heterojunction, using the polarization absorption characteristics of black phosphorus and the infrared absorption characteristics of the two, and combining the characteristics and advantages of the two, an infrared photodetector with polarization detection function is obtained.

[0035] Specific steps are as follows:

[0036] 1. Substrate selection

[0037] Intrinsic germanium with a thickness of 0.9 mm was selected as the substrate.

[0038] 2. Preparation of mercury cadmium telluride material

[0039] A mercury cadmium telluride material with a thickness of 8 μm was prepared on the surface of the germanium substrate by molecular beam epitaxy.

[0040] 3. Preparation of insulating layer

[0041] A mask was formed on the mercury cadmium telluride material by photolithography, the mercury cadmium telluride with a thickness of 150 nm was removed by argon ion etching, and aluminum oxide with a thickness of 150 nm was evaporated by an electron beam evaporation method.

[0042] 4. Preparation and transfer of two-dimensional semiconductor materials

[0043] A two-dimensional semiconductor material black phosphorus with a thickness of 100 nm was prepared by a mechanical exfoliation method, and transferred to a silicon substrate. The two-dimensional semiconductor material was covered with a layer of polypropylene carbonate film, heated to fully contact with the two-dimensional semiconductor material, and the polypropylene carbonate film was removed from the substrate after cooling down. At this time, the two-dimensional semiconductor material was adsorbed by the polypropylene carbonate. The film was moved under the microscope to make the two-dimensional semiconductor material align with the junction of mercury cadmium telluride and aluminum oxide, and heated to make contact slowly; after cooling down, the sample was soaked in acetone to completely dissolve the polypropylene carbonate. So far, the mercury cadmium telluride-black phosphorus van der Waals heterojunction was prepared.

[0044] 5. Preparation of metal electrode

[0045] Metal electrode patterns were prepared by electron beam lithography; metal electrodes with 15 nm of titanium and 45 nm of gold were prepared by electron beam evaporation technology; combined with a lift-off method, the metal film was removed to obtain the metal electrodes. The final structure of the device is shown in FIG. 1.

[0046] 6. Infrared photoelectric performance test

[0047] Under the condition that the bias voltage of the device was zero, the device was irradiated with a medium-wave infrared laser with a wavelength of 4324 nm, the change of the current of the device with time was tested, and the experimental results are shown in FIG. 2(a). It can be seen that when the bias voltage is zero, the current changes rapidly and obviously as the laser is turned on and off. The device exhibits a sensitive light response to the laser with a wavelength of 4324 nm, indicating that the developed black phosphorus-mercury cadmium telluride heterojunction device can realize medium-wave infrared detection, and the device can work under zero bias conditions without external voltage, thus effectively reducing the power consumption of the detector.

Example 2

[0048] The Example 2 of the present disclosure will be described in detail below with reference to the accompanying drawings:

[0049] The present disclosure develops a black phosphorus-mercury cadmium telluride mixed dimensional heterojunction infrared detector. By combining the traditional infrared photoelectric material mercury cadmium telluride and the emerging two-dimensional material black phosphorus to form a van der Waals heterojunction, using the polarization absorption characteristics of black phosphorus and the infrared absorption characteristics of the two, and combining the characteristics and advantages of the two, an infrared photodetector with polarization detection function is obtained.

[0050] Specific steps are as follows:

[0051] 1. Substrate selection

[0052] Intrinsic germanium with a thickness of 0.9 mm was selected as the substrate.

[0053] 2. Preparation of mercury cadmium telluride material

[0054] A mercury cadmium telluride material with a thickness of 8 μm was prepared on the surface of the germanium substrate by molecular beam epitaxy.

[0055] 3. Preparation of insulating layer

[0056] A mask was formed on the mercury cadmium telluride material by photolithography, the mercury cadmium telluride with a thickness of 120 nm was removed by argon ion etching, and aluminum oxide with a thickness of 120 nm was evaporated by an electron beam evaporation method.

[0057] 4. Preparation and transfer of two-dimensional semiconductor materials

[0058] A two-dimensional semiconductor material black phosphorus with a thickness of 50 nm was prepared by a mechanical exfoliation method, and transferred to a silicon substrate. The two-dimensional semiconductor material was covered with a layer of polypropylene carbonate film, heated to fully contact with the two-dimensional semiconductor material, and the polypropylene carbonate film was removed from the substrate after cooling down. At this time, the two-dimensional semiconductor material was adsorbed by the polypropylene carbonate. The film was moved under the microscope to make the two-dimensional semiconductor material align with the junction of mercury cadmium telluride and aluminum oxide, and heated to make contact slowly; after cooling down, the sample was soaked in acetone to completely dissolve the polypropylene carbonate. So far, the mercury cadmium telluride-black phosphorus van der Waals heterojunction was prepared.

[0059] 5. Preparation of metal electrode

[0060] Metal electrode patterns were prepared by electron beam lithography; metal electrodes with 10 nm of titanium and 35 nm of gold were prepared by electron beam evaporation technology; combined with a lift-off method, the metal film was removed to obtain the metal electrodes. The final structure of the device is shown in FIG. 1.

[0061] 6. Infrared photoelectric performance test

[0062] Under the condition that the bias voltage of the device was zero, the device was irradiated with a medium-wave infrared laser with a wavelength of 4135 nm, the change of the current of the device with time was tested, and the experimental results are shown in FIG. 2(b). It can be seen that when the bias voltage is zero, the current changes rapidly and obviously as the laser is turned on and off. The device exhibits a sensitive light response to the laser with a wavelength of 4135 nm, indicating that the developed black phosphorus-mercury cadmium telluride heterojunction device can realize medium-wave infrared detection, and the device can work under zero bias conditions without external voltage, thus effectively reducing the power consumption of the detector.

Example 3

[0063] The Example 3 of the present disclosure will be described in detail below with reference to the accompanying drawings:

[0064] The present disclosure develops a black phosphorus-mercury cadmium telluride mixed dimensional heterojunction infrared detector. By combining the traditional infrared photoelectric material mercury cadmium telluride and the emerging two-dimensional material black phosphorus to form a van der Waals heterojunction, using the polarization absorption characteristics of black phosphorus and the infrared absorption characteristics of the two, and combining the characteristics and advantages of the two, an infrared photodetector with polarization detection function is obtained.

[0065] Specific steps are as follows:

[0066] 1. Substrate selection

[0067] Intrinsic germanium with a thickness of 0.9 mm was selected as the substrate.

[0068] 2. Preparation of mercury cadmium telluride material

[0069] A mercury cadmium telluride material with a thickness of 8 μm was prepared on the surface of the germanium substrate by molecular beam epitaxy.

[0070] 3. Preparation of insulating layer

[0071] A mask was formed on the mercury cadmium telluride material by photolithography, the mercury cadmium telluride with a thickness of 100 nm was removed by argon ion etching, and aluminum oxide with a thickness of 100 nm was evaporated by an electron beam evaporation method.

[0072] 4. Preparation and transfer of two-dimensional semiconductor materials

[0073] A two-dimensional semiconductor material black phosphorus with a thickness of 150 nm was prepared by a mechanical exfoliation method, and transferred to a silicon substrate. The two-dimensional semiconductor material was covered with a layer of polypropylene carbonate film, heated to fully contact with the two-dimensional semiconductor material, and the polypropylene carbonate film was removed from the substrate after cooling down. At this time, the two-dimensional semiconductor material was adsorbed by the polypropylene carbonate. The film was moved under the microscope to make the two-dimensional semiconductor material align with the junction of mercury cadmium telluride and aluminum oxide, and heated to make contact slowly; after cooling down, the sample was soaked in acetone to completely dissolve the polypropylene carbonate. So far, the mercury cadmium telluride-black phosphorus van der Waals heterojunction was prepared.

[0074] 5. Preparation of metal electrode

[0075] Metal electrode patterns were prepared by electron beam lithography; metal electrodes with 12 nm of titanium and 40 nm of gold were prepared by electron beam evaporation technology; combined with a lift-off method, the metal film was removed to obtain metal electrodes. The final structure of the device is shown in FIG. 1.

[0076] 6. Infrared photoelectric performance test

[0077] Under the condition that the bias voltage of the device was zero, the device was irradiated with a medium-wave infrared laser with a frequency of 1 Hz and a wavelength of 4034 nm, the change of the current of the device with time was tested, and the experimental results are shown in FIG. 2(c). It can be seen that when the bias voltage is zero, the current changes rapidly and obviously as the laser is turned on and off. The device exhibits a sensitive light response to the laser with a wavelength of 4034 nm, indicating that the developed black phosphorus-mercury cadmium telluride heterojunction device can realize medium-wave infrared detection, and the device can work under zero bias conditions without external voltage, thus effectively reducing the power consumption of the detector.

[0078] The above descriptions are only preferred embodiments of the present disclosure and are not intended to limit the present disclosure. For those skilled in the art, the present disclosure may have various modifications and changes. Any modification, replacement, improvement, etc. made within the thought and principle of the present disclosure are all included in the protection scope of the present disclosure.

[0079] It is to be understood that the terms “including”, “comprising”, “consisting” and grammatical variants thereof do not preclude the addition of one or more components, features, steps, or integers or groups thereof and that the terms are to be construed as specifying components, features, steps or integers.

[0080] If the specification or claims refer to “an additional” element, that does not preclude there being more than one of the additional element.

[0081] It is to be understood that where the claims or specification refer to “a” or “an” element, such reference is not be construed that there is only one of that element.

[0082] It is to be understood that where the specification states that a component, feature, structure, or characteristic “may”, “might”, “can” or “could” be included, that particular component, feature, structure, or characteristic is not required to be included.

[0083] Where applicable, although state diagrams, flow diagrams or both may be used to describe embodiments, the invention is not limited to those diagrams or to the corresponding descriptions. For example, flow need not move through each illustrated box or state, or in exactly the same order as illustrated and described.

[0084] Methods of the present invention may be implemented by performing or completing manually, automatically, or a combination thereof, selected steps or tasks.

[0085] The term “method” may refer to manners, means, techniques and procedures for accomplishing a given task including, but not limited to, those manners, means, techniques and procedures either known to, or readily developed from known manners, means, techniques and procedures by practitioners of the art to which the invention belongs.

[0086] The term “at least” followed by a number is used herein to denote the start of a range beginning with that number (which may be a ranger having an upper limit or no upper limit, depending on the variable being defined). For example, “at least 1” means 1 or more than 1. The term “at most” followed by a number is used herein to denote the end of a range ending with that number (which may be a range having 1 or 0 as its lower limit, or a range having no lower limit, depending upon the variable being defined). For example, “at most 4” means 4 or less than 4, and “at most 40%” means 40% or less than 40%.

[0087] When, in this document, a range is given as “(a first number) to (a second number)” or “(a first number)-(a second number)”, this means a range whose lower limit is the first number and whose upper limit is the second number. For example, 25 to 100 should be interpreted to mean a range whose lower limit is 25 and whose upper limit is 100. Additionally, it should be noted that where a range is given, every possible subrange or interval within that range is also specifically intended unless the context indicates to the contrary. For example, if the specification indicates a range of 25 to 100 such range is also intended to include subranges such as 26-100, 27-100, etc., 25-99, 25-98, etc., as well as any other possible combination of lower and upper values within the stated range, e.g., 33-47, 60-97, 41-45, 28-96, etc. Note that integer range values have been used in this paragraph for purposes of illustration only and decimal and fractional values (e.g., 46.7-91.3) should also be understood to be intended as possible subrange endpoints unless specifically excluded.

[0088] It should be noted that where reference is made herein to a method comprising two or more defined steps, the defined steps can be carried out in any order or simultaneously (except where context excludes that possibility), and the method can also include one or more other steps which are carried out before any of the defined steps, between two of the defined steps, or after all of the defined steps (except where context excludes that possibility).

[0089] Further, it should be noted that terms of approximation (e.g., “about”, “substantially”, “approximately”, etc.) are to be interpreted according to their ordinary and customary meanings as used in the associated art unless indicated otherwise herein. Absent a specific definition within this disclosure, and absent ordinary and customary usage in the associated art, such terms should be interpreted to be plus or minus 10% of the base value.

[0090] Thus, the present invention is well adapted to carry out the objects and attain the ends and advantages mentioned above as well as those inherent therein. While the inventive device has been described and illustrated herein by reference to certain preferred embodiments in relation to the drawings attached thereto, various changes and further modifications, apart from those shown or suggested herein, may be made therein by those of ordinary skill in the art, without departing from the spirit of the inventive concept the scope of which is to be determined by the following claims.