CN115832081A - Scintillator nuclear radiation detector and preparation method thereof - Google Patents

Scintillator nuclear radiation detector and preparation method thereof Download PDF

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CN115832081A
CN115832081A CN202211546827.3A CN202211546827A CN115832081A CN 115832081 A CN115832081 A CN 115832081A CN 202211546827 A CN202211546827 A CN 202211546827A CN 115832081 A CN115832081 A CN 115832081A
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scintillator
layer
type
transition metal
visible light
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张�浩
刘文上
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Synae Microelectronics Co ltd
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Synae Microelectronics Co ltd
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Abstract

The invention discloses a scintillator nuclear radiation detector and a preparation method thereof, wherein the scintillator nuclear radiation detector comprises a scintillator, a transition metal chalcogenide layer, an electrode layer, a first visible light reflecting layer and a second visible light reflecting layer; the transition metal chalcogenide layer is tightly bonded on the first surface of the scintillator by van der waals force, and includes an N-type heavily doped region, an intrinsic or lightly doped I region, and a P-type heavily doped region which are laterally arranged; the electrode layer is arranged on the first surface of the scintillator and comprises an N-type electrode covering the N-type heavily doped region and a P-type electrode covering the P-type heavily doped region; the first visible light reflecting layer is disposed over the electrode layer, and the second visible light reflecting layer is disposed on the second surface of the scintillator. According to the scintillator nuclear radiation detector, the TMDCs layer and the scintillator are directly combined through Van der Waals force, total reflection of light at an interface is avoided, optical coupling efficiency is improved, and the structure of the detector is simplified.

Description

Scintillator nuclear radiation detector and preparation method thereof
Technical Field
The invention relates to the technical field of nuclear radiation detection, in particular to a scintillator nuclear radiation detector and a preparation method thereof.
Background
The nuclear radiation detector mainly comprises a track detector, a gas detector, a scintillation detector, a semiconductor detector and the like, wherein the scintillation detector consists of a scintillator capable of emitting visible light or ultraviolet light under the excitation of nuclear radiation, an optical collecting component and a photoelectric conversion device, can detect high-energy charged particles or neutral particles (such as neutrons, gamma rays and X rays), can meet different physical requirements of fast time response, high detection efficiency, high large-area sensitivity, high energy resolution, good position resolution and the like, and becomes one of the most widely applied nuclear radiation detectors at present through continuous development. On the other hand, since a general scintillation detector is formed by coupling three modules, the loss of light in the propagation process is inevitably brought; the insertion of light guides and optical couplers is a common method to improve the optical coupling efficiency, but it complicates the structure and fabrication process of the detector. In addition, the nuclear radiation transmitted through the scintillator generally causes irradiation damage to the photoelectric conversion module at the rear end, resulting in a reduction in the lifetime of the detector. Therefore, the selection of a proper photoelectric conversion device and the reasonable overall structure design in combination with the characteristics of the scintillator are of great significance in further optimizing the performance of the scintillator detector.
Transition metal chalcogenides (TMDCs) are a typical two-dimensional layered material, and the most common semiconducting TMDCs are MoS composed of group VIB transition metals Mo, W, S and Se 2 、MoSe 2 、WS 2 And WSe 2 The two-dimensional material can be tightly combined with the substrate material under the action of van der Waals force. Studies have shown that TMDCs-based photodetectors have several advantages, such as very high responsivity and specific detectivity, and that TMDCs-based PIN diodes, while having these advantages, also have responsivityThe photoelectric detector has the advantages of high speed, self-driving and low power consumption, and can be used as a preferred device of a photoelectric detection assembly in a scintillation detector.
In view of the above advantages of TMDCs, it is necessary to apply TMDCs to a nuclear radiation detector to solve the problems of the conventional nuclear radiation detector.
Disclosure of Invention
The invention aims to provide a scintillator nuclear radiation detector based on TMDCs transverse PIN homojunction and a preparation method thereof.
The technical scheme adopted by the invention for solving the technical problems is as follows: providing a scintillator nuclear radiation detector comprising a scintillator, a transition metal chalcogenide layer, an electrode layer, a first visible light reflecting layer, and a second visible light reflecting layer;
the scintillator has a first surface and a second surface opposite to each other, the transition metal chalcogenide layer is tightly bonded on the first surface of the scintillator by van der Waals force, and the transition metal chalcogenide layer comprises an N-type heavily doped region, an intrinsic or lightly doped I region and a P-type heavily doped region which are transversely arranged; the electrode layer is arranged on the first surface of the scintillator and comprises an N-type electrode covering the N-type heavily doped region and a P-type electrode covering the P-type heavily doped region;
the first visible light reflecting layer is disposed over the transition metal chalcogenide layer and electrode layer, and the second visible light reflecting layer is disposed on a second surface of the scintillator.
Preferably, the scintillator is an inorganic scintillator, an organic scintillator, or a rare earth ion doped garnet scintillator.
Preferably, the material of the inorganic scintillator includes at least one of NaI (Tl), csI (Tl), cs (Na), znS (Ag), and BGO.
Preferably, the organic scintillator is a plastic scintillator or an anthracene crystal.
Preferably, the material of the rare earth ion doped garnet scintillator comprises at least one of cerium-doped yttrium aluminum garnet crystals, praseodymium-doped lutetium garnet crystals and cerium-doped gadolinium gallium aluminum garnet crystals.
Preferably, the scintillator nuclear radiation detector further comprises a passivation layer; the passivation layer overlies the transition metal chalcogenide layer and an electrode layer, and the first visible light reflecting layer overlies the electrode layer.
Preferably, the first visible light reflecting layer is made of at least one of Al, au, pt, ag, ti and alloys thereof; or, the first visible light reflecting layer is made of an inorganic insulating material with light reflecting performance.
Preferably, the second visible light reflecting layer is made of at least one of Be, mg and Al.
Preferably, the transition metal chalcogenide layer has a thickness of 1nm to 100nm;
the material of the transition metal chalcogenide layer comprises MoS 2 、MoSe 2 、WS 2 、WSe 2 At least one of them.
Preferably, for the light doping in the intrinsic or lightly doped I-region, the concentration of the light doping is 10 13 -10 17 cm- 3 。
Preferably, the concentration of heavy doping is 10 for the heavy doping of the N type heavy doping region and the P type heavy doping region 19 -10 21 cm- 3 。
Preferably, the material of the N-type electrode comprises at least one of Ni, ti, cr, al, ag, mo, W and the alloy of the above metals; the thickness of the N-type electrode is 5nm-200nm.
Preferably, the material of the P-type electrode comprises at least one of Au, pd, pt, co, mo, W and alloy of the above metals; the thickness of the P-type electrode is 5nm-200nm.
Preferably, an N-type interface layer is further formed between the N-type heavily doped region and the N-type electrode; and a P-type interface layer is also formed between the P-type electrodes of the P-type heavily doped region.
The invention also provides a preparation method of the scintillator nuclear radiation detector, which comprises the following steps:
s1, providing a scintillator, wherein an intrinsic or lightly doped transition metal chalcogenide layer is arranged on a first surface of the scintillator;
s2, carrying out patterning treatment on the intrinsic or lightly doped transition metal chalcogenide layer to form a first window exposing part of the transition metal chalcogenide layer;
s3, forming an N-type interface layer on the surface of the transition metal chalcogenide layer in the first window region by taking the photoresist as a mask to realize local N-type doping and form an N-type heavily doped region;
s4, depositing metal by taking the photoresist as a mask, and depositing the metal on the first window to form an N-type electrode, wherein the N-type electrode covers the N-type heavily doped region;
s5, patterning the intrinsic or lightly doped transition metal chalcogenide layer to form a second window exposing part of the transition metal chalcogenide layer;
s6, forming a P-type interface layer on the surface of the transition metal chalcogenide layer in the second window region by taking the photoresist as a mask to realize local P-type doping and form a P-type heavily doped region;
s7, depositing metal by taking the photoresist as a mask, and depositing the metal on the second window to form a P-type electrode, wherein the P-type electrode covers the P-type heavily doped region;
and S8, arranging a first visible light reflecting layer above the transition metal chalcogenide layer, and arranging a second visible light reflecting layer on the second surface of the scintillator.
The invention has the beneficial effects that: arranging a transition metal chalcogenide layer (TMDCs layer) on a scintillator by utilizing Van der Waals force, forming an N-type heavily doped region, an intrinsic or lightly doped I region and a P-type heavily doped region which are transversely arranged by localized electron doping, wherein the N-type heavily doped region and the P-type heavily doped region are covered by corresponding electrodes to form a transverse PIN diode (transverse PIN homojunction); compared with the existing scintillator nuclear radiation detector, the transverse PIN diode and the scintillator are directly combined by preparing the transition metal chalcogenide layer (TMDCs layer) on the scintillator by utilizing Van der Waals force, and an optical collection system is omitted.
The scintillator nuclear radiation detector of the invention has the following advantages: 1) The TMDCs layer is directly combined with the scintillator through Van der Waals force, so that an air layer at an interface is avoided, the optical refractive index of the TMDCs is higher than that of the scintillator, the total reflection of light at the interface is avoided, an optical coupling agent and a light guide are omitted, the optical coupling efficiency is improved, and the structure of the detector is simplified; 2) TMDCs are two-dimensional materials with nanometer-scale thickness, and can easily pass through the nuclear radiation of the scintillator without damaging the device; 3) The photoelectric device adopts a structure of a transverse PIN homojunction prepared by localized electronic doping, so that the detector has the characteristics of high responsivity, high specific detection rate, high response speed, self-driving and low power consumption; 4) Visible light emitted by the excited scintillator is reflected back and forth between the two reflecting layers, so that light absorption of the PIN junction is enhanced, and the responsiveness is improved.
Drawings
The invention will be further described with reference to the accompanying drawings and examples, in which:
FIG. 1 is a schematic plan view of a scintillator nuclear radiation detector in accordance with an embodiment of the present invention;
FIG. 2 is a schematic cross-sectional view of a scintillator nuclear radiation detector in accordance with an embodiment of the present invention;
FIG. 3 is a schematic plan view of a periodic array of scintillator nuclear radiation detectors in accordance with an embodiment of the present invention.
Detailed Description
For a more clear understanding of the technical features, objects and effects of the present invention, embodiments of the present invention will now be described in detail with reference to the accompanying drawings.
As shown in fig. 1-3, a scintillator nuclear radiation detector in accordance with an embodiment of the present invention may include a scintillator 100, a transition metal chalcogenide layer (TMDCs layer) disposed on the scintillator 100, an electrode layer, a passivation layer 130, a first visible light reflecting layer 110, and a second visible light reflecting layer 120.
The scintillator 100 has a first surface and a second surface opposite to each other, and the transition metal chalcogenide layer is tightly bonded to the first surface of the scintillator 100 by van der waals force, thereby preventing the optical coupling efficiency from being reduced due to the presence of an interface air layer therebetween. The electrode layer covers the transition metal chalcogenide layer, the passivation layer 130 covers the transition metal chalcogenide layer and the electrode layer, the first visible light reflecting layer 110 covers the passivation layer 130, and the second visible light reflecting layer 120 covers the second surface of the scintillator 100.
The transition metal chalcogenide layer includes a laterally arranged N-type heavily doped region 210, an intrinsic or lightly doped I-region 200, and a P-type heavily doped region 220. An intrinsic or lightly doped I region 200 is connected between the heavily N doped region 210 and the heavily P doped region 220 as a conductive channel therebetween.
For light doping in the intrinsic or lightly doped I region 200, the concentration of light doping is 10 13 -10 17 cm- 3 (ii) a For heavy doping of N-type heavily doped region 210 and P-type heavily doped region 220, the concentration of heavy doping is 10 19 -10 21 cm- 3 。
Correspondingly, the electrode layer includes an N-type electrode 310 and a P-type electrode 320, the N-type electrode 310 covers the heavily doped N-type region 210, and the P-type electrode 320 covers the heavily doped P-type region 220.
The diffusion of carriers is induced among the N-type heavily doped region 210, the intrinsic or lightly doped I region 200, and the P-type heavily doped region 220 by a carrier concentration gradient, and a space charge region is formed in the intrinsic or lightly doped I region 200 in a thermal equilibrium state, thereby forming a lateral PIN diode (lateral PIN homojunction) of the scintillator 100 nuclear radiation detector.
The scintillator nuclear radiation detector adopts a back incidence structure, the top and the bottom are respectively provided with a first visible light reflecting layer 110 and a second visible light reflecting layer 120, when nuclear radiation enters the scintillator 100 from the bottom, the scintillator 100 is excited to emit visible light, the visible light radiation is reflected back and forth between the first visible light reflecting layer 110 and the second visible light reflecting layer 120 to ensure that the visible light radiation is fully absorbed by a TMDCs layer, the TMDCs layer absorbs incident photons to generate electron-hole pairs, and then the electron-hole pairs are separated and drifted under the action of a built-in electric field or an external bias electric field in a space charge region to generate voltage or current to be output in a circuit, thereby realizing the nuclear radiation detection.
When the scintillator nuclear radiation detector works, the transverse PIN diode is in a zero bias or reverse bias state.
Alternatively, a single detector device may be formed by disposing a transition metal chalcogenide layer (TMDCs layer), an electrode layer, a passivation layer 130, a first visible light reflecting layer 110, a second visible light reflecting layer 120, and the like on the scintillator 100, as shown in fig. 1 to 2; alternatively, a periodic array structure is formed, as shown in fig. 3.
Specifically, the scintillator 100 may be, but is not limited to, an inorganic scintillator, an organic scintillator, or a rare earth ion doped garnet scintillator.
Further, the material of the inorganic scintillator includes at least one of NaI (Tl), csI (Tl), cs (Na), znS (Ag), and BGO. The organic scintillator is a plastic scintillator 100 or an anthracene crystal. The material of the rare earth ion doped garnet scintillator comprises at least one of cerium-doped yttrium aluminum garnet crystal (Ce: YAG), praseodymium-doped lutetium garnet crystal (Pr: luAG) and cerium-doped gadolinium gallium aluminum garnet crystal (Ce: GAGG).
On the scintillator 100, the thickness of the transition metal chalcogenide layer (TMDCs layer) is 1nm to 100nm. The material of the transition metal chalcogenide layer comprises MoS 2 、MoSe 2 、WS 2 、WSe 2 At least one of them.
The N-type electrode 310 and the heavily doped N-type region 210 are in N-type ohmic contact, and the P-type electrode 320 and the heavily doped P-type region 220 are in P-type ohmic contact.
In the electrode layer, the material of the N-type electrode 310 includes at least one of low work function metals such as Ni, ti, cr, al, ag, mo, W, and alloys thereof. The material of the P-type electrode 320 includes at least one of Au, pd, pt, co, mo, W, and alloys thereof.
The thickness of the N-type electrode 310 may be 5nm to 200nm. The thickness of the P-type electrode 320 may be 5nm to 200nm.
Further, an N-type interface layer 211 is formed between the N-type heavily doped region 210 and the N-type electrode 310; a P-type interface layer 221 is also formed between the P-type electrodes 320 of the P-type heavily doped region 220.
A passivation layer 130 overlies the electrode layer and the transition metal chalcogenide layer. The passivation layer 130 may be usedThe preparation method is a vapor deposition method, a chemical vapor deposition method or a spin coating method. The passivation layer 130 is formed using an inorganic insulating material, preferably SiO, or an organic insulating material 2 、Al 2 O 3 Or HfO 2 。
The first visible light reflecting layer 110 is made of at least one of Al, au, pt, ag, ti and alloys thereof; alternatively, the first visible light reflecting layer 110 is made of an inorganic insulating material having a good light reflecting property, such as TiO 2 MgO, etc. or reflecting paint, etc. To ensure the light reflecting effect, the first visible light reflecting layer 110 is preferably an Al metal plating layer having a thickness of not less than 1 μm.
The second visible light reflecting layer 120 is made of at least one of materials with small atomic numbers, such as Be, mg, al, and the like, and may Be made of a simple substance or an alloy of the above materials, or may have a single-layer or multi-layer structure. The second visible light reflecting layer 120 is preferably an Al metal plating layer of 0.1 to 5 μm in order to achieve both the light reflecting effect and the transmittance of nuclear radiation.
The photon energy of the visible light generated by the excited radiation of the scintillator 100 is not less than the forbidden band width of the TMDCs material. The first visible light reflecting layer 110 and the second visible light reflecting layer 120 reflect the visible light excited by the radiation of the scintillator 100, and the second visible light reflecting layer 120 can isolate the ambient visible light and can transmit more than 80% of the X-rays with the wavelength less than 0.1 nm.
Referring to fig. 1-3, a method of fabricating an embodiment of a scintillator nuclear radiation detector of the present invention may include the steps of:
s1, providing a scintillator 100, wherein an intrinsic or lightly doped transition metal chalcogenide layer is arranged on a first surface of the scintillator 100.
The transition metal chalcogenide layer can be grown directly on the scintillator 100 or transferred to the scintillator 100 after formation. Preferably, the transition metal chalcogenide layer is formed by growing directly on the surface of the scintillator 100 using a chemical vapor deposition process.
And S2, carrying out patterning treatment on the intrinsic or lightly doped transition metal chalcogenide layer to form a first window exposing part of the transition metal chalcogenide layer.
In this example, a cerium-doped gadolinium gallium aluminum garnet crystal (Ce: GAGG) was used as the scintillator 100, and a micro-mechanical lift-off method was used to prepare a multi-molecular layer (10-20 nm) WSe on the scintillator 100 2 The thin film acts as a transition metal chalcogenide layer. The step S2 may specifically include:
s2.1 at WSe 2 Spin-coating S1815 photoresist on the surface of the film, spin-coating for 5S at 500 rpm, spin-coating for 60S at 4000 rpm to form a photoresist film layer with a thickness of about 1500nm, and drying at 110 ℃ for 3min.
S2.2, photoetching, namely exposing the photoresist through a photomask with a preset layout, wherein the exposure dose is 40mJ/cm 2 And fixing in a large amount of deionized water immediately after development for 20 seconds, thereby forming a pattern structure on the photoresist.
And S3, forming an N-type interface layer 211 on the surface of the transition metal chalcogenide layer in the first window region by taking the photoresist as a mask to realize local N-type doping and form an N-type heavily doped region 210.
The N-type interface layer 211 is formed by physical deposition or chemical deposition, or by physically or chemically changing TMDCs in the first window region by using a surface treatment method such as a plasma process. The N-type interfacial layer 211 may have a thickness of 1nm to 5nm.
The N-type interface layer 211 is highly electron doped TMDCs or other conductive material with high doping concentration and doping concentration of 10 19 -10 21 cm- 3 And can be used as an electron transport layer.
The Fermi level of the N-type interface layer 211 is lower than the conduction band of the TMDCs, the absolute value of the energy difference between the two is not more than 0.078eV at room temperature, or the Fermi level of the N-type interface layer 211 is not lower than the conduction band of the TMDCs, so that electrons are promoted to be transferred from the N-type interface layer 211 to the TMDCs, local electron doping of the TMDCs is realized, and the N-type heavily doped region 210 is formed.
In the embodiment, in combination with the steps S1-S2, a large amount of chalcogen vacancies are artificially generated in a plurality of molecular layers of the TMDCs crystal surface layer by using Ar plasma treatment to form an interface layer rich in chalcogen vacancies, the chalcogen vacancies are doped in the interface layer to introduce high-concentration electrons, so that N-type heavy doping is caused to be used as an N-type interface layer 211, and then the TMDCs in contact with the N-type interface layer 211 is doped into an N-type heavy doping region 210 by charge transfer.
In the Ar plasma treatment, the setting of the respective parameter conditions may be as follows: ar flow rate is 80sccm, power is 200W, and processing time is 10s.
S4, depositing metal by using the photoresist as a mask, depositing the metal on the first window to form an N-type electrode 310, wherein the N-type electrode 310 covers the N-type heavily doped region 210.
Specifically, the patterned photoresist is used as a mask, metal is deposited by a physical vapor deposition method, and then the photoresist is removed to form a metal electrode layer, i.e., the N-type electrode 310.
In this embodiment, an electron beam evaporation is used to stack 10nm Ti and 60nm Au, and then the photoresist is removed to form the N-type electrode 310.
And S5, patterning the intrinsic or lightly doped transition metal chalcogenide layer to form a second window exposing part of the transition metal chalcogenide layer.
And S6, forming a P-type interface layer on the surface of the transition metal chalcogenide layer in the second window region by taking the photoresist as a mask to realize local P-type doping and form a P-type heavily doped region 220.
The portion of the transition metal chalcogenide layer between the first window and the second window is an intrinsic or lightly doped I region 200 that serves as a conductive channel.
The P-type interface layer 221 is formed by physical deposition or chemical deposition, or by physically or chemically changing the TMDCs of the second window region by a surface treatment method such as a plasma process. The P-type interfacial layer 221 may be 1-5nm thick.
The P-type interface layer 221 is TMDCs with high hole doping concentration or other conductive material with high doping concentration, with doping concentration of 10 19 -10 21 cm- 3 And can be used as a hole transport layer.
The Fermi level of the P-type interface layer 221 is higher than the valence band of the TMDCs, and the absolute value of the energy difference between the two is not more than 0.078eV at room temperature, or the Fermi level of the P-type interface layer 221 is not higher than the valence band of the TMDCs, so that electrons are promoted to be transferred from the TMDCs to the P-type interface layer 221, local holes of the TMDCs are doped, and the P-type heavily doped region 220 is formed.
The specific operation of step S6 may include:
s6.1 in WSe 2 Spin-coating S1815 photoresist on the surface, spin-coating for 5S at 500 rpm, spin-coating for 60S at 4000 rpm to form a photoresist film layer with a thickness of about 1500nm, and drying at 110 ℃ for 3min.
S6.2, photoetching, namely exposing the photoresist through a photomask with a preset layout, wherein the exposure dose is 40mJ/cm 2 And fixing in a large amount of deionized water immediately after development for 20 seconds, thereby forming a pattern structure on the photoresist.
Specifically, the P-type interface layer 221 is formed by physical deposition or chemical deposition using a patterned photoresist as a mask, or the P-type interface layer 211 is formed by physically or chemically changing the TMDCs of the second window region using a surface treatment method such as a plasma process.
In this example, O is used 2 The plasma treatment oxidizes several molecular layers on the surface of TMDCs crystals to non-stoichiometric transition metal oxide MoO X Or WO X An interfacial layer; the interface layer is rich in oxygen vacancies, and high-concentration electrons are introduced into the oxygen vacancies by doping to cause N-type heavy doping; meanwhile, the transition metal oxide has a high work function, a Fermi level lower than the valence band of TMDCs, and can be used as a P-type interface layer 221, and TMDCs electrons are transferred to the P-type interface layer 221, so that the TMDCs in contact with the P-type interface layer are doped into a P-type heavily doped region 220.
At O 2 In the plasma processing, the setting of each parameter condition may be as follows: o is 2 The flow rate was 40sccm, the power was 200W, and the treatment time was 20s.
S7, depositing metal by using the photoresist as a mask, depositing the metal on the second window to form a P-type electrode 320, wherein the P-type electrode 320 covers the P-type heavily doped region 220.
And depositing metal by using the patterned photoresist as a mask through a physical vapor deposition method, and then removing the photoresist to form a metal electrode layer, namely the P-type electrode 320.
In this embodiment, an electron beam evaporation is used to stack 10nm Pd and 60nmPt, and then the photoresist is removed to form the P-type electrode 320.
Through the above steps, the N-type electrode 310 and the P-type electrode 320 form electrode layers; the portion of the transition metal chalcogenide layer between heavily N-doped region 210 and heavily P-doped region 220 forms an intrinsic or lightly doped I region 200.
S8, a first visible light reflecting layer 110 is provided over the transition metal chalcogenide layer, and a second visible light reflecting layer 120 is provided on the second surface of the scintillator 100.
Wherein a passivation layer 130 is further disposed over the electrode layer and the transition metal chalcogenide layer before the first visible light reflecting layer 110 is disposed. The passivation layer 130 is prepared by physical vapor deposition, chemical vapor deposition, or spin coating. The passivation layer 130 is formed using an inorganic insulating material, preferably SiO, or an organic insulating material 2 、Al 2 O 3 Or HfO 2 。
Preferably, the passivation layer 130 is Al deposited by an atomic layer deposition process to have a thickness of 20nm to 2000nm 2 O 3 And a passivation layer. Further preferably, the sample is put into the reaction cavity of the atomic layer deposition equipment, and H is used 2 O and TMA (trimethylaluminum) as reaction sources, 100nm Al was deposited at 120 deg.C 2 O 3 A thin film as a passivation layer 130.
The first visible light reflecting layer 110 is made of at least one of Al, au, pt, ag, ti and alloys thereof; alternatively, the first visible light reflecting layer 110 is made of an inorganic insulating material having a good light reflecting property, such as TiO 2 MgO, etc. or reflecting paint, etc. To ensure the light reflecting effect, the first visible light reflecting layer 110 is preferably an Al metal plating layer with a thickness of not less than 1 μm, for example, an Al metal plating layer of 2 μm evaporated by electron beam.
The second visible light reflecting layer 120 is made of at least one of materials with small atomic numbers, such as Be, mg, al, etc., and may Be made of a simple substance or an alloy of the above materials, or may have a single-layer or multi-layer structure. To achieve both the light reflecting effect and the transmittance of nuclear radiation, the second visible light reflecting layer 120 is preferably a 0.1-5 μm Al metal coating, such as a 0.5 μm Al metal coating by electron beam evaporation.
Through the above steps, the scintillator nuclear radiation detector can be manufactured as a single device as shown in fig. 1-2, or as a periodic array structure as shown in fig. 3.
The above description is only an embodiment of the present invention, and not intended to limit the scope of the present invention, and all modifications of equivalent structures and equivalent processes performed by the present specification and drawings, or directly or indirectly applied to other related technical fields, are included in the scope of the present invention.

Claims (10)

1. A scintillator nuclear radiation detector includes a scintillator, a transition metal chalcogenide layer, an electrode layer, a first visible light reflective layer, and a second visible light reflective layer;
the scintillator has a first surface and a second surface opposite to each other, the transition metal chalcogenide layer is tightly bonded on the first surface of the scintillator by van der Waals force, and the transition metal chalcogenide layer comprises an N-type heavily doped region, an intrinsic or lightly doped I region and a P-type heavily doped region which are transversely arranged; the electrode layer is arranged on the first surface of the scintillator and comprises an N-type electrode covering the N-type heavily doped region and a P-type electrode covering the P-type heavily doped region;
the first visible light reflecting layer is disposed over the transition metal chalcogenide layer and electrode layer, and the second visible light reflecting layer is disposed on a second surface of the scintillator.
2. The scintillator nuclear radiation detector of claim 1, wherein the scintillator is an inorganic scintillator, an organic scintillator, or a rare earth ion doped garnet scintillator.
3. The scintillator nuclear radiation detector of claim 2 wherein the material of the inorganic scintillator includes at least one of NaI (Tl), csI (Tl), cs (Na), znS (Ag), and BGO;
the organic scintillator is a plastic scintillator or an anthracene crystal;
the material of the rare earth ion doped garnet scintillator comprises at least one of a cerium-doped yttrium aluminum garnet crystal, a praseodymium-doped lutetium garnet crystal and a cerium-doped gadolinium gallium aluminum garnet crystal.
4. The scintillator nuclear radiation detector of claim 1, further comprising a passivation layer; the passivation layer overlies the transition metal chalcogenide layer and an electrode layer, and the first visible light reflecting layer overlies the electrode layer.
5. The scintillator nuclear radiation detector of claim 1 wherein the first visible light reflecting layer is made of at least one of Al, au, pt, ag, ti, and alloys thereof; or the first visible light reflecting layer is made of an inorganic insulating material with light reflecting performance;
the second visible light reflecting layer is made of at least one of Be, mg and Al.
6. The scintillator nuclear radiation detector of any of claims 1-5, wherein the transition metal chalcogenide layer has a thickness of 1nm to 100nm;
the material of the transition metal chalcogenide layer comprises MoS 2 、MoSe 2 、WS 2 、WSe 2 At least one of them.
7. The scintillator nuclear radiation detector of any of claims 1-5, wherein for the light doping in the intrinsic or lightly doped I region, the concentration of light doping is 10 13 -10 17 cm -3 ；
For the heavy doping of the N type heavy doping region and the P type heavy doping region, the concentration of the heavy doping is 10 19 -10 21 cm -3 。
8. The scintillator nuclear radiation detector of any of claims 1-5, wherein the material of the N-type electrode includes at least one of Ni, ti, cr, al, ag, mo, W, and alloys thereof; the thickness of the N-type electrode is 5nm-200nm;
the material of the P-type electrode comprises at least one of Au, pd, pt, co, mo, W and the alloy of the metals; the thickness of the P-type electrode is 5nm-200nm.
9. The scintillator nuclear radiation detector of any of claims 1-5, wherein an N-type interface layer is further formed between the heavily N-doped region and the N-type electrode; and a P-type interface layer is also formed between the P-type electrodes of the P-type heavily doped region.
10. A method of manufacturing a scintillator nuclear radiation detector according to any of claims 1 to 9, comprising the steps of:
s1, providing a scintillator, wherein an intrinsic or lightly doped transition metal chalcogenide layer is arranged on a first surface of the scintillator;
s2, carrying out patterning treatment on the intrinsic or lightly doped transition metal chalcogenide layer to form a first window exposing part of the transition metal chalcogenide layer;
s3, forming an N-type interface layer on the surface of the transition metal chalcogenide layer in the first window region by taking the photoresist as a mask to realize local N-type doping and form an N-type heavily doped region;
s4, depositing metal by taking the photoresist as a mask, and depositing the metal on the first window to form an N-type electrode, wherein the N-type electrode covers the N-type heavily doped region;
s5, patterning the intrinsic or lightly doped transition metal chalcogenide layer to form a second window exposing part of the transition metal chalcogenide layer;
s6, forming a P-type interface layer on the surface of the transition metal chalcogenide layer in the second window region by taking the photoresist as a mask to realize local P-type doping and form a P-type heavily doped region;
s7, depositing metal by taking the photoresist as a mask, and depositing the metal on the second window to form a P-type electrode, wherein the P-type electrode covers the P-type heavily doped region;
and S8, arranging a first visible light reflecting layer above the transition metal chalcogenide layer, and arranging a second visible light reflecting layer on the second surface of the scintillator.
CN202211546827.3A 2022-12-05 2022-12-05 Scintillator nuclear radiation detector and preparation method thereof Pending CN115832081A (en)

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