TWI376035B - X-ray photodetector of quantum dots thin film and photodetecting method thereof - Google Patents

Description

1376035 VI. Description of the invention: [Technical field to which the invention belongs], Fang Fangfa: It is about the X-ray sensing element of the thin layer of quantum dots and the sensation '(4) is related to - _ formed by electrostatic bonding The self-formed thin layer of quantum dots is used to make the sensing 7C component of A y into X first and its sensing method. [Prior Art] # Due to the size of the semiconductor quantum dot crystals, the dimensions of the three dimensions are small, and the motion of the internal electrons in the three-dimensional square is limited. However, in quantum The effect cannot be ignored. Under the unscaled, the nature of the object is not only affected by the size, but also the shape is very close. This is especially true for the neutron point where the optical and electrical properties are all dependent on the quantum confinement effect. Since quantum dots have characteristics such as small particle size, high surface energy, and large proportion of surface atoms, their special spectral characteristics and south quantum efficiency can be utilized. _ The quantum production of the stomach is divided into several methods: (1) chemicai couoidal, which is synthesized by chemical sol method, which is simple in process and can be mass-produced. (2) Self-assembly method ), which employs a molecular-beam epitaxy or chemical vapor deposition process, and utilizes the principle of lattice mismatch to cause quantum dots to grow on a specific substrate surface. It can mass produce regular quantum dots, which are mostly used for thin layer formation on substrates. (3) Lithography and etching, with beam 1376035 1 or electron beam directly on the substrate to make the desired It takes a lot of time to produce in large quantities. (4):: quite approach), the method of applying voltage in two-dimensional ^Pll1>gate two=limit, can control the gate (Gate) to change the quantum dot (four) shape suitable for academic research, can not be large produce.胶,,,, currently colloidal semiconductor quantum dots have been used as light-breaking components such as light sensing components and photovoltaic cells. In recent years; ^ developed the production of photoelectrons with colloidal semiconductor quantum dots = surgery, for example using spin-coated colloidal quantum dots. , technology (Soiut should sell tlng) of quantum dot polymerized nanocomposites. In the autumn, the tube uses a high-performance production device to generate the amount by these techniques; the thickness of the thin layer of the sub-point and the thickness of the thin layer of the quantum dot cannot be precisely controlled, and only a thin layer of quantum dots can be used. Applied to a planar substrate: A thin layer of controlled quantum dots is formed at a specific location. The present inventors have felt that the above-mentioned deficiency can be improved, and the present invention which is reasonable in design and effective in improving the above-mentioned deficiency is proposed. SUMMARY OF THE INVENTION In view of the above, the main object of the present invention is to provide an X-ray sensing 7C piece of a quantum dot thin layer which is a self-forming (Self-Assembly) quantum dot thin layer formed by electrostatic bonding. , utilizing the internal quantum efficiency of semiconductor quantum dots (High lnternal Quantum

Efficiency): Photocurrent is generated by irradiation of x-ray rays, and the intensity of the photo-ray is detected by detecting the magnitude of the photo-current, and is used as a sensing element of X-ray. ~ 4 1376035 The x-ray sensing element comprising the thin layer of quantum dots of the present invention, at least: two: a substrate electrode, which is a substrate capable of transmitting -x light rays; and a plurality of layers of contacts are attached to the substrate On the electrode, each layer of the quantum

The point 溥 layer is stacked by a plurality of quantum dot crystal groups H through electrostatic bonding and is adjacent::: sub-point 溥 layer ^ V . ^ Μ 其中 该 该 该 该 该 该 该 该 该 该 该 该 该Produce a light under illumination

The quantum dot (10) η in the uppermost layer has a potential difference between the electrode and the contact electrode; the metal electrode and the substrate plate electrode and the metal electrode are between the dendron and the substrate electrode. I, the current measured by the metal current = current (4) Another purpose of measuring the power below the potential difference is that Jiang also 仏 v ΈΙ. + lies in a thin layer of quantum dots First sensing method, the method comprising at least a step of 曰 能 能 $ $ 乂匕 . . . . . . . ( ( ( ( ( ( ( ( 土 土 土 土 土 土 土 土 土 土 土 土 土 土 土 土 土 土 土 土 土 土 土 土 土On the surface of the substrate electrode, a plurality of layers of the substrate are electrically layered and covered on the substrate electrode, and the seven m electrode is in contact with the uppermost layer of the quantum dot thin layer. (e) providing a potential difference between the metal-proof electrode and the substrate electrode to form a thin layer of the quantum dots to generate a photoelectric:: (4)^ 丁 丁 μ μ '丨L, (g) detected under the potential difference The photocurrent; and (h) calculating the intensity of the X-ray. - The size of the wall is determined by the thin layer forming technique, and the thin layer of the present invention is formed by the number and thickness of the autonomously formed thin layer, which is compared with the conventional quantum dots through the electrostatic bonding. The complex layer process is formed, except that the quantum dot 5 t mode can be easily controlled, and the specific thin layer of the thin layer forming the quantum dot is controlled in any non-planar 纴糂μ to form a neutron point adjacent to the early w Γ 聋on. And using the high-intra-four sub-point crystal of the semiconductor quantum dot to generate light under the irradiation of the X-ray ray; and then detecting the magnitude of the photocurrent to determine the intensity of the X-ray ray, and achieving the purpose of sensing X-ray . In order to understand the features and technical contents of the present invention, please refer to the stipulations of the sinister test, and the syllabus is only used to refer to the description. The figure first illustrates the x-ray sensing example of the thin layer of the quantum dot of the present invention, and the step of the step is used to describe the photo sensing method of the present invention in detail. In the preferred embodiment of the present invention, the embodiment is described, and The same reference numerals will be used to refer to the same or similar elements in the drawings and the description. The measurement -f-graph is the x-ray of the thin layer of the quantum dot of the present invention. The schematic diagram of the preferred embodiment of the invention is as shown in the figure. The X-ray sensing device 100 of the present invention comprises a substrate electrode 11 layer = a thin layer 120, a metal electrode 130 and a unit 140. The substrate electrode 110 is a substrate capable of transmitting an X-ray and a line 200. A plurality of quantum dot thin layers 12G are attached to the substrate electrode 11 (each layer = quantum dot thin) The layers are composed of a plurality of quantum dot crystals 12nl, and the thin layers of the f-position dots are 12 to 12n. Electrostatic bonding stacked o concubine 5 wherein some of the quantum dot crystals Hyun 12nl having high internal quantum efficiency (High 6 1376035

Interna丨 Quantum Efficiency), due to the influence of the Quantum-Confinement Effect, produces photocurrent under the illumination of the X-ray ray 200. The metal electrode 13 is in contact with the uppermost layer of the quantum dot layer 12n, wherein the metal electrode! There is a potential difference between the metal plate and the substrate. The detecting unit 14 is electrically connected to the substrate electrode 110 and the metal electrode 130, and is under the potential difference, and measures the current between the metal electrode 13 0 and the substrate oxygen electrode 11 , to measure the potential difference.

The magnitude of the photocurrent below it is calculated by calculating the magnitude of the photocurrent to determine the strength of the X-ray ray 200. Therefore, it can be provided as a function of sensing the light. Among them, because the size of these quantum dot crystals is as small as the nanometer level, the influence of the electronic interface to the confinement effect of the stars, in addition to the original energy band structure into a split energy level structure, will also make the original The indirect energy gap becomes an energy band structure close to the direct energy gap, so that its lowest energy state density = ensity Qf States) is greatly increased. Therefore, the photon of the photon photon will generate several electrons to make the carrier or electrify. Bulk multiplication, that is, a phenomenon of doubling = electron or hole (Carrier MultlplicatiGn), and the substrate electrode 11 of the present invention is formed by a chemical reaction to form a plurality of electrostatics on the surface of the base electrode 110. The group (1) gands) (1), #电配基 111 is electrostatically bonded to the quantum dot crystal 1211' of the quantum dot layer (2) to form a quantum dot thin layer 121 on the substrate electrode. In addition, the above-mentioned quantum dot thin layers ι2 ΐ ~ (10), wherein the quantum dots crystals on the thin layer of the 5 layers of the S haibu sub-point have 7 1376035 * » on the surface, and the electrical properties are the same, The individual dendritic points on the adjacent thin layer of quantum dots: the electrostatic properties of the surface of the body are different, and by electrostatic bonding: such as the thin layer of sub-dots 122 and the thin layer of quantum dots 123, their individual The sub-pixel crystal 1221 and the quantum dot crystal 1231 are electrostatically charged by the surface of the quantum dot crystal 1221, and the adjacent quantum dot thin layer 122 is formed by electrostatic interaction of the quantum dot crystals 1221 and 1231. Heap between the thin layer 123 of quantum dots: abutting. In this way, a thin layer of quantum dots with different electrostatic charges is layered one after another, stacked by electrostatic bonding, and the number and thickness of the plurality of quantum dot thin layers 120 are controlled by stacking and stacking quantum dots. Forming a thin layer of quantum dots of the layer-by-Layer Self-Assembly. Furthermore, the quantum dot corpus callus for illuminating X-rays on the thin layer of the quantum dot of the present invention is a spherical granular nanocrystal (nan〇crySfal), which may comprise a semiconductor quantum dot crystal having germanium, preferably. CdTe quantum dot crystals are selected 'but may also contain suitable semiconductor materials such as MgS, MgSe, MgTe,

Compounds of Group II-VI such as CaS, CaSe, CaTe, SrS, SrSe, SrTe, BaS, BaSe, BaTe, ZnS, ZnSe, ZnTe, CdS, CdSe, HgS, HgSe and HgTe; or 'such as GaAs, GaP, Compounds of Group III-V such as GaAs-P, GaSb, InAs, InP, InSb, AlAs, AlP, AlGaAs, InGaAs, and AlSb. The substrate electrode of the present invention is a conductive substrate capable of penetrating x-ray rays, and may be a glass substrate, a germanium substrate, an aluminum oxide (AUO3) substrate, or a gallium arsenide (GaAs) substrate, and is preferably permeable. Indium tin oxide (ΙΤ0) substrate. Next, the step flow of the method of the present invention is applied, and the x-ray sensing method using the thin layer of the neutron point is described in detail. Referring to the second figure, #, is the flow chart of the x-ray sensing method using the thin layer of quantum dots of the present invention. As shown in the figure, in the X-ray sensing method of the present invention, first, the 2 ray 200 is provided to penetrate one of the substrate electrodes 110 (step 300). Next, a plurality of electrostatic ligands 111 are formed on the substrate electrode H0 by a chemical reaction to form a surface (step 310). Then, a plurality of surfaces are provided with a first-electron neutron dot crystal 丨211, and are bonded to the electrostatic ligands m to form a layer-first photo-electrode thin layer 121 of the quantum dots. 110 (step 32A), wherein the quantum dot crystal 12γ having the first conductivity is electrostatically bonded to the electrostatic ligands (1). After the formation of the sub-point thin layer 121 in step 32, the multi-layer quantum dot thin layer 120 is overlaid and overlaid on the second electrode 110 (step 330). In step 33 ", a thin layer of quantum dots to be formed to two "=layer number η, then formed - the metal electrode (10) = (four) above the quantum layer _ 12η of the uppermost layer (step 34 〇). However < ' Providing a potential difference between the metal electrode 13A and the substrate electrode (step 350). Next, irradiating a ray beam 2G() to the quantum dots: layers 121~12n to generate a photocurrent (step 36) 〇). Then, measure the current between the metal electrode 130 and the substrate electrode ji〇 to detect the photocurrent (4) below the potential difference (read _, and then calculate the size of the light ^ to judge _ X The intensity of the light ray (step, the last two bundles of this process, to achieve the luminosity of the thin layer of quantum dots of the present invention: the method, wherein the size of the quantum dot crystal is as small as the nanometer level, because it is a child The influence of the quantum brown limit effect (Quantum-c〇nf inement Ef 9 1376035, in addition to the original continuous band structure into a split energy structure, will also make the original indirect energy gap close to direct The energy band structure of the energy gap makes the density of the lowest energy state increase greatly, so By the impact of X-ray photons, several electrons are generated, that is, the carrier or the charged body is multiplied, and the phenomenon of multiplying electrons or holes (carrlerMultlpllcatlon) is generated, and photocurrent is generated. mj

; ^ 330 330 towel feet bar a fine Shao process A amount 1 = layer: Γ molding process. Referring to the third figure, it is the second aspect of the present invention. The second reading layer is autonomously recorded by ayeb by_Layerself. As shown in the figure, when the step is said to be in the middle, the thin layer 121 of the / zizi point is formed on the substrate electrode 110, and the second layer of the second layer is formed by the second layer of the quantum dots. A plurality of entanglements with a second electrical quantity are formed and assembled with the first electrical version 1221. After the second sub-crystal (2) forms a thin layer (2) of the second electrical quantum dot through the electrostatic bond, the quantum dot has the second electrical quantum layer of the quantum layer (=: connected; ==Da, ® sub-dot thin layer] Chuan Xiyu Gu Fan into the complex layer to the required quantum process. If in the step coffee, 6 Dacheng has not yet reached the required amount = Ϊ layer 120 of the independent molding system Steps 331 and the number of layers are sequentially performed, and then the step 332 is continued, so that the thin layer of the Xia Zi point with the different electrostatic electricity 1736035 :: is formed with the second electrical property 126..·, with the strip - Electrical lining layer J22, J24, make these quantum dots thin]: point • layer (3), 125, 127.., and, the special mutual bond is wrong, this will be connected to 1 with ^ Layer (10).

After the electrostatic bonding, the thin layer of the self-bonding layer is formed by itself, and the thin layer of the quantum dot is formed, and the control "2' and % can also be measured by the repeated layer, the number of layers and the thickness of the self-forming layer. The invention relates to the x-ray sensing element of the quantum dot thin layer of the invention and the thin point of the sensing point: to: ί The quantum form formed by the independent molding process of the electrostatic bonding = the thin layer of the quantum dot is controlled in addition to the inter-generation The number of layers and thickness formed = formula: a thin layer of quantum dots can be formed on any non-planar structure.

= quantum confinement effect of the body' causes the quantum dot crystal to generate photocurrent under the illumination of the X tangent, and can be used as the sensing dimming by detecting the large photocurrent, 'to determine the strength of the X-ray ray' Its function. The present invention has been described above in terms of a preferred embodiment, and is not intended to limit the invention, and various modifications and changes may be made without departing from the spirit and scope of the invention. The scope of the invention is defined by the scope of the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS The first figure is a schematic view of a preferred embodiment of an X-ray sensing element of a thin layer of quantum dots of the present invention. 1376035 The second figure is a flow chart of the steps of the present invention. A self-formed quantum dot thin layer using a thin layer of tantalum light sensing method. The third figure is a detailed flow chart for forming a plurality of layers of the present invention. [Main component symbol description] : X-ray sensing device] 1 0 : substrate electrode • 111 : electrostatic ligand 120 : plural quantum dot thin layer 1 21~12 η : quantum dot thin layer 121]~12η]: quantum Dot crystal] 3 0 . metal electrode ] 40 : detection unit 200 : X-ray step 300 to 380 : method step 12

Claims (1)

• * VII. Scope of application for patents·· 1. A thin-layer photo-sensing component of a quantum dot, comprising at least: a substrate electrode, which is a substrate through which a ray beam can penetrate; a thin layer of J-level quantum dots, Attached to the substrate electrode, the upper layer is composed of a plurality of quantum dot crystals, and the quantum: Λ曰 is stacked adjacent to each other through electrostatic bonding, and the θa body can produce two streams of I under the X-ray irradiation. The quantum layer of the uppermost layer of the dot crystal has a potential difference between the _, . , and δ hai substrate electrodes, and is electrically connected to the substrate electrode and the metal electrode, and the current 'detects _ potential difference The sensing element between the optoelectronics underneath, the impact of the X-ray of the thin layer of the quantum dot described above, and the current of the 吝 先 先 is the tensor of the quantum dot crystal that is multiplied by the X-ray photon , + Mul_ncatl0n) effect. Electronics or Work A (Cancer sensing element, where each layer of the amount of the device = thin layer of X-ray surface with the same electrostatic properties. ... # layer of the set of points of the crystal 4. If you apply for a patent The third sensing element of the range, wherein the adjacent ones of the measuring layers are lighted to the 溥 layer ' layer, and the individual electrostatic currents of the surface of the 13-point crystals are different from each other. The adjacent quantum dots continue to be stacked by the electrostatic bonding of the quantum dot crystals; the surface of the quantum dots described in the patent scope is described as the surface of the quantum dots. Base 6. A thin layer of quantum dots according to claim 5 of the patent application scope: a Xiazi point crystal' to form a thin layer of the quantum dot on the substrate = 8. The quantum dot thin as described in the scope of claim The layer of the light-receiving component, which is selected from the group of I丨MgS^gSe-MgTe-CaS-CaSe-CaTe.SrS^rSe; Te: BaS, BaSe, BaTe, ZnS, ZnSe, ZnTe, CdS a group consisting of CdSe, CdTe, HgS, HgSe, and HgTe. 9·Bright light sensing of a thin layer of quantum dots as described in claim 1 The component, the Yin quantum dot crystal system is selected from the mv group compound: 14 1376035 GaAs, GaP, GaAs-P, GaSb, InAs, InP, InSb, AlAs, A1P, AlGaAs, InGaAs and AlSb. The photosensitive light sensing element of the quantum dot thin layer according to claim 1, wherein the 5 Xuan substrate electrode is an indium tin oxide (I το) substrate, a germanium substrate, and an aluminum oxide Ul2〇3) A substrate, or a gallium arsenide (GaAs) substrate. The n-ray sensing element of the quantum dot thin layer according to claim 1, wherein the detecting unit further comprises calculating a magnitude of the photocurrent to determine the intensity of the X-ray. 12. An optical sensing method using a thin layer of quantum dots, comprising at least the steps of: providing a substrate electrode that is penetrated by X-ray rays; • forming a plurality of electrostatic ligands (1 igands) Forming a surface of the substrate electrode; forming a plurality of thin layers of quantum dots over the electrostatic bonding layer and overlying the substrate electrode; forming a metal electrode contacting the uppermost layer of the quantum dots; providing a potential difference between the metal electrode and the a substrate electrode; irradiating an X-ray beam to the thin layers of the quantum dots to generate a photocurrent; detecting the photocurrent under the potential difference; and calculating a magnitude of the photocurrent to determine the X-ray Strength. 15 1376035 ”. The method of optical sensing according to the above-mentioned item i2, wherein a thin layer of a thin layer of a sub-dot is applied to the substrate electrode by a thin layer of dots, and a plurality of quantum steps are formed: v, more at least The following steps form a layer with a first electrical - θ ^ pole; a thin layer of Xia Zi points on the substrate to form a thin layer of the quantum dot with a second electrical property; and a thin layer of the zizi point The thin layer of the quantum dot with the first electric quantity::: the second layer of the quantum dot with the second electric quantum dot The quantum dot crystals pass through the electrostatic (four), and become the same as the "electrical coupling." The sensing method of claim 12, wherein the first == bit base is electrostatically bonded. The child is too Japanese, and is formed with X: 'Sense:::Special 2:::Using a quantum dot thin layer Μ光雹/y, L system is the quantum dot crystal by X 1376035 • The effect of photon impact, which produces multiplied electrons or holes. 17. The X-ray sensing method using a thin layer of quantum dots according to the scope of claim π, wherein the quantum dot crystal system is a germanium containing germanium crystal. 18. The X-ray sensing method using a thin layer of quantum dots according to claim 12, wherein the quantum dot crystal system is selected from the group consisting of π_νι: MgS, MgSe, MgTe, CaS, CaSe, CaTe, A group consisting of SrS, SrSe, SrTe, BaS, BaSe, BaTe, ZnS, ZnSe 'ZnTe, CdS, CdSe, CdTe, HgS, HgSe, and HgTe. 19. The X-ray sensing method using a thin layer of quantum dots according to the scope of claim i2, wherein the quantum dot crystal system is selected from the group III-V compound φ, GaAs, GaP, GaAs-P, GaSb, A group consisting of InAs, InP, lnSb, A1 As, A1P, AlGaAs, InGaAs, and AlSb. 20. The X-ray sensing method using a thin layer of quantum dots according to claim 12, wherein the substrate electrode is an indium tin oxide (IT〇) substrate, a substrate, a gasification (A1203) A substrate, or a gallium arsenide (GaAs) substrate. 21. A method of photoluminescence using a thin layer of quantum dots comprising at least 17 steps: providing: a substrate electrode that can be penetrated by X-rays; a surface; a plurality of electrostatic ligands (1) coffee ds) The substrate electrode table k is provided with a plurality of surfaces, a chamber, and a crystal of the dice, and the ligand is formed by electrostatic bonding. An electrical layer is placed on the substrate electrode; the electrical surface provides a plurality of surface bands with a first electrical bond to form a layer of the lining... one of the quantifiers The quantum dot thin layer is formed by the quantum dot crystal formed by the electric bond, and is thinned by the second electric property: the thin layer of the quantum dot is in contact with the uppermost layer of the electrode of the genus The quantum dot is on the thin layer. It is worse than the metal electrode and the substrate; the thin layer of the quantum dots is used to generate a photocurrent; the photocurrent is under a potential difference of 5 hp; and the light is different. The magnitude of the current is used to determine the strength of the X-ray. The use of the quantum dot thin layer described in the 21st item of the Qing Dynasty and the & transfer read the first electrical quantum dot crystal system - the ruthenium ligand through the electrostatic bond. Thin layer 23. The X-ray sensing method using quantum dots 18 1376035 as described in the above-mentioned application, wherein the first electrical property is different from the electrical electrical property of the second electrical system. 24. The X-ray sensing method using a thin layer of quantum dots according to claim 21, wherein the photocurrent system is such that the quantum dot crystals are impacted by X-ray photons to generate multiplied electrons or holes. (Carrier Multiplication) effect. 25. The X-ray sensing method using a thin layer of quantum dots according to claim 21, wherein the quantum dot crystal system is a semiconductor crystal containing germanium. 26. The X-ray sensing method using a thin layer of quantum dots according to claim 21, wherein the quantum dot crystal system is selected from the group consisting of bismuth-VI compounds: MgS, MgSe, MgTe, CaS, CaSe, CaTe, A group consisting of SrS, SrSe, SrTe, BaS, BaSe, BaTe, ZnS, ZnSe, ZnTe, CdS, CdSe, CdTe, HgS, HgSe, and HgTe. 27. The X-ray sensing method using a thin layer of quantum dots according to claim 21, wherein the quantum dot crystal system is selected from the group consisting of bismuth-V compounds: GaAs, GaP, GaAs-P, GaSb, InAs, A group consisting of InP, InSb, AlAs, A1P, AlGaAs, InGaAs, and AlSb. 28. The X-ray sensing method using a quantum dot thin layer 19 1376035 • according to claim 21, wherein the substrate electrode is an indium tin oxide (ITO) substrate, a germanium substrate, and an oxidation. Aluminum (A 1203 ) substrate, or a gallium arsenide (GaAs) substrate. 20