TWI287628B - Ultraviolet-visible lighting detector - Google Patents

Abstract

One kind of ultraviolet-visible lighting detector characterizes a sensing film, which is formed by nano holes of silicon dioxide (mesoporous silica, MS) with forming by nano hole silicon dioxide embedded in the passageway a quantum dot array of nanocrystal (NC) or germanium. This invention with ultraviolet-visible lighting detector has an extremely good stability obviously.

Description

, 1287628 • Nine, invention description: • [Technical field of the invention] The present invention relates to an ultraviolet-visible light detector, and more particularly to a nanometer quantum dot ultraviolet-visible light detector, Excellent performance stability. [Prior Art] Ultraviolet (UV) detectors have been widely used in fire monitoring, pollution analysis, astronomical observation, medical instruments, and even military applications. Recently, it is hoped to use ultraviolet light detection. The detector is equipped with a light-emitting diode (LED) such as indium gallium nitride (InGaN) or a laser to form an ultraviolet-blue light data access system. However, in the ultraviolet light detection process, the absorption of ultraviolet light by the conventional ultraviolet light detector is likely to cause the temperature of the component in the detector to rise, which may affect the performance of the component and even cause damage to the component. Therefore, in addition to the need for a certain signal/noise ratio, the UV detector is also very important. • Materials currently used in the preparation of UV detectors are still based on semiconductor materials such as gallium nitride (GaN) and aluminum gallium nitride (AlGaN). Because the price of these materials is not low, it has caused the manufacturing cost to be reduced. In order to solve this problem, many research groups have tried to replace the semiconductor materials of the three-five metals with bismuth-based materials in order to achieve the purpose of calling for the province and reducing costs. However, in addition to the relatively complete research on the large-scale carbonized niobium, the remaining niobium-based materials still have a lot of room for further development. A study previously supported by the US Science Foundation (USNSF), 1287628, proposed the _ anode treatment side #f" 奈子点点光光赖11, which is 1 nanometer by electrophoresis. After the fine grain, it is used to detect the silk consumption side of the good money, and then extremely =: several characteristics that cause the good Shi Xi nano quantum point ultraviolet light detection: (1) the size of the scoop is large... Has the following broken rlr %) nanometer 1 sub-point size; (2) quantum dot stacking good

Ancient (7 high-quality interface); (3) the quality of the film at the sub-point has not yet met the three conditions of the material quantum dot UV design 'or prepare this side (four) process is proposed, because 1 ::::—The nano-quantum dot ultraviolet ray that meets these three characteristics is “very important thing.” [Summary]

In order to solve the shortcomings of the conventional ultraviolet photometric detector, the object of the present invention is to provide an ultraviolet-visible light detector based on silic〇i> It can also be used to detect visible light in addition to detecting ultraviolet light, and is compatible with existing semiconductor processes. For the purpose of the present invention, the ultraviolet-visible light detection according to the present invention is characterized in that it has a sensing layer, and the sensing layer is composed of a nanometer pore magnetite (mesoporous silica, Ms). And consisting of a quantum dot array of nanocrystals (NC) 矽 (or 锗) formed in a pore in the nanoporous ceria. The sensing layer has an excellent photo-electric response when illuminated by a source of light in the wavelength range of ultraviolet light and visible light. 1287628 The ultraviolet-visible light detector of the present invention may further comprise: a stone substrate; a sensing layer formed on the germanium substrate; and an indium tin oxide formed on the sensing layer. ITO) layer;

The sensory layer consists of a nanoporous silica crystal (MS) and a nanocrystal (NC) formed on the inner wall of a pore formed in the nanoporous ceria. (or 锗) of quantum dot arrays, and the sensing layer produces a photoelectric response after absorbing light sources in the ultraviolet and/or visible wavelength range. The ultraviolet-visible light detector of the present invention prepares the sensing layer by using the (10) base material composed of the nanostructures composed of yttrium (Si) and oxygen (0), so the ultraviolet/visible light detector of the present invention The preparation can be completely compatible with the current semiconductor manufacturing, and since the sensing layer is composed only of 11, wrong and oxygen, the problem of process turn-up and contamination does not occur.

The present invention will be further exemplified by the following detailed description and embodiments. Those skilled in the art of the present invention can do the improvement and modification of the 4b Xuzhishen drink, but still do not deviate from the scope of the invention. [Embodiment] The ultraviolet light and light detection indicated by the scoop human root sr month , a pot of ytterbium - a high-density quantum or error formed by the nano-micron, 1287628 nc_Ge formed on the pore of the nanoporous dioxodioxide _ (hereinafter referred to as the external pores r and啰 has a high porosity (:^) of up to 75%, an extremely large surface area (approximately ^(9), and an adjustable pore size (2~1〇nm), ie its =, preparation: thus the invention The sensing layer is = butyl; the quantum dot _ of the nc-Si (or noGe) is formed on the surface of the milk-cut channel. The quasi-there is the size of the nc sword in the quantum dot array (or the size of the nc sword in the present invention, There is no restriction on the system, but it is based on the size of the hole diameter of the nanopore in the nanopore, which is preferably 2 to 5 nm. In addition, the aforementioned (or nc-Ge) reading is not found in the present day. Limitation of the system, but in order to make the sensing layer of the present invention have a better photoelectric response, the density is preferably ΐχΐ() 17~5χΐ〇ΐ8 cm3 〇

The method of forming a cluster of quantum dots in the nanopore of the nano-holes in the evening is not particularly limited in the present invention, and those skilled in the art can select the contents disclosed in the specification of the present invention. Any suitable conventional technique can be used to exemplify, including ion implantation, oxidative precipitation, conventional chemical deposition (CVD), and high-intensity inductively coupled plasma (ICP) chemical gas. Phase deposition (CVD) method, plasma enhanced CVD (PECVD), plasma assist atomic layer chemical vapor deposition (PAALD), etc. But it is not limited to this. Among them, the preparation of nc-Si 8 , 1287628 (or nc-Ge) quantum dot array with paalD is the best, because this technology can greatly increase the density of the formed nano quantum dots. It can overcome the problems of long process time, high temperature and interface deterioration of other technologies.

^ Taking PAALD as an example. The sensing layer of the present invention can be used as a nanotemplate by using nanoporous ceria as a nanotemplate, and using PAALD to perform a quantum dot formation in a hydrogen grid with a crushed (five) pyroelectric slurry. Two steps, such as nuclear exposure and quantum dot synthesis, form a surface state (surface_state) and a quantum limit (:m trace conflement, Qc) on the surface of c in the nano-template at low temperature (less than 400t). Hook distribution of high density X two-dimensional nc-Si (or nc_Ge) quantum dot arrays. Referring to Fig. 1, there is shown a schematic diagram of the step of forming quantum dots of n〇S1 (or nc_Ge) in nanoholes by using pAALD. The eight-D system-single-peripheral shot is divided into two parts: step a and step b. i I 2 A part of the station Wei is for the nano-quantum axis of the nucleus. The middle part of the step is the synthesis of quantum dots. The steps of this method are 祠2/4 ^ hunting by the energy-reducing part of the pulp-reducing part of the inner wall 14 of the channel 12 of the channel 12 to the diffusion channel of the knife and exposing the quantum lining into sweat;)' In step B, 'continue to use ===: nucleation: poly 16 施 force 峨 hole dioxide (four) hole =;) 〇 and hydrogen point 2W quantum dot nucleation (four) 18 on = = towel 'to make amount (four) on the wall Nano quantum dots 22. Connected to the hole

Repeat with the process cycle formed by the step :: = perform the step A to expose the nucleation point and the 9.1287628, the synthesis of quantum dots, and finally form in the pores of the nanoporous ceria 10 • 12 A uniformly distributed high density three-dimensional nc-Si (or nc-Ge) quantum dot array 24. Such a method of forming nanorods of quantum dots by PAALD in a pore of a nanometer pore contains a plurality of reactions. First, • Plasma-dissolved SiHn (or GeHn) diffuses in the form of nanoscale clusters • into the nanopores, which are then absorbed and embedded in the nanopore dioxide. A large number of Si_〇H groups on the inner wall of the pores of the nanopores can pass the hydrogen_elimination reaction (HER) [Si_〇H +

SiHn(GeHn) — Si-0-SiHm(GeHm) + H2] is activated for the anchoring sites of (or GeHn). Next, a further degassing reaction [Si-0_SiHm(GeHm) -> Si_0_Sin(Ge)n + H2] will

Si-0_SiHm(GeHm) is converted into %(()) clusters in the nano-holes of the nano-holes, and then forms quantum dots. Month (described in PAALD to prepare the sensibility of the ultraviolet-visible light detector of the present invention) When measuring the layer, it is prepared by using the dissociated particles with high kinetic energy, and the cycle of the appropriate spring residual dew/f sub-synthesis, so that the process has low temperature (below 400 ° C) and fast (less than 2 minutes), and can be used for large-area preparation, and can be compatible with the process of ultra-large integrated circuit (10) y 丨 e e (4) integtration, VLSI). The present invention is not particularly limited, and those skilled in the art will understand that it can be prepared by referring to the previously published literature. For example, by using a solution for preparing a nanoporous dioxide dioxide precursor (p_·SQhitiQn>;x_(四)法形1287628, formed on the P-type slab substrate, but is not limited thereto. The foregoing lead solution, for example, can be obtained by using a triplet copolymer (for example, Pluronic P-123, abbreviated as P123) Acid solution (acid-catalyzed) The sol-gel is prepared by, but not limited to, the above-mentioned acid-catalyzed cerium oxide sol-gel, for example, by tetraethyl 〇rthosilicate, TEOS. , water, a mixture of hydrogen chloride and ethanol is prepared at 6 Torr to 8 Torr, refluxing at 60 ° C for 60 to 120 minutes, but is not limited thereto. The molar ratio of the above mixture is 1: 0.008 〇. 〇3 : 3.5~5.0 : • 0·003~0 force 3 : 4〇 (TEOS/P123/water/vaporized hydrogen/ethanol). The above-mentioned lead solution is preferably matured at room temperature after the preparation is completed. (age) 3~6 hours, then spin-coated on the enamel substrate at 3,000 rpm. Finally, dry at 40~60 °C for 4~6 hours, then bake at i〇0~120°c. In the hour, the preparation of the nanoporous cerium oxide can be completed. Please refer to the second figure (B) for one of the metal-oxide-silicon (M0S) structures fabricated by the sensing layer of the present invention. A schematic cross-sectional view of the embodiment. The MOS structure is composed of a P-type (p_type) germanium substrate 26 and a nano-hole germanium dioxide layer 28 formed on the P-type germanium substrate 26. And an indium tin oxide (IT0) layer 30 formed on the nanoporous ceria layer 28. The P-type germanium substrate 26 and the oxidized steel tin (1) layer 3 can be divided and forged. - Electrical connection points 32, 34. Referring again to the second figure (A), it is a three-dimensional schematic diagram of the fine structure of the nanopore dioxide layer in the MOS structure of the first working figure (9). It can be seen from the figure that the twisted quantum dots 36 are formed at the bottom of the inner wall % of the pores of the nanopore dioxide layer 28 and are deposited upward. 1287628 Since the nano-quantum dot array "# in the sensing layer according to the present invention has a large number of surface states, it has a visible and excellent luminous efficacy in the range of blue light and visible light at room temperature ( > ι❻/〇), which means that it has an excellent and large number of excitons (electron hole pairs). In addition, since the sensing layer of the present invention has an extremely thin ceria pore wall which facilitates the passage of the carrier, the sensing layer of the present invention can be reduced to the extent that the nano quantum dot is not further reduced (for example, to Inm) has a very high photoelectric response in the blue and visible light range, for example, a photoelectric response of 0.4 A/W at 40 〇 nm under 3 V bias. The aforementioned blue and visible light bands refer to light of 320_700 nm. The sensing layer of the invention has excellent performance stability, and it can still have certain performance under a long time of 10 mW laser irradiation. When comparing the sample of the ultraviolet-visible light detector prepared by the sensing layer of the present invention with a conventional ultraviolet light detector, it can be found that the sensing layer of the present invention has good photoelectric response (responsivity). A MOS structure having a memory characteristic layer of the present invention is first prepared by spin coating a 300 nm thick nanoporous ceria layer on a P-type germanium substrate. The above-mentioned nanoporous ceria layer can be prepared by adding an ethanol solution of a triad copolymer (Pluronic P-123, P123) to an acid-catalyzed dioxide sol-gel (sol_gel). In order to make a precursor solution. The aforementioned acid-catalyzed two-gasification 12 1287628 T 〇 S gum is obtained by mixing tetraethyl hydrazine (10) raethyl 〇rth 〇 silicate, S), water, hydrogenated hydrogen and ethanol at 6 〇 8 〇 t: Under reflux 1 UXlng) Prepared for 60~120 minutes. The molar ratio of the foregoing mixture is ^.〇〇8^〇.〇3 : 3.5^5.0 : 0.〇〇3^〇.〇3 : 40 (TEOS/P123/7JC/ 2, alcohol). The lead solution was cooked at room temperature (4) for 3 to 6 hours. 1)~6 was spin-coated on the Shixi substrate at 3, 嶋_, 3 〇 seconds. Finally, dry it for 4 to 6 hours under the armpits, and then bake it for 3 hours at rc~12 to make a nanometer for growing nc-Si (or nc-Ge). The nano-holes are oxidized in the mold layer. The nano-holes are formed by a body-crystal reaction mechanism. In this reaction mechanism, the nanostructures are formed by molecular self-assembly. Then 'by the PAALD technique (with a 1 second / 3 second duty cycle (this CyCle) pulse hydrogenation stone (1 sccm) and hydrogen (2 〇 Osccm) / pulse hydrogen (2 〇〇)) in the nano-hole nc_Sl is formed on the inner surface of the pores of the oxidized stone layer (p〇re_channels). After this process, nc_Si can be formed on the inner surface of the pore layer (p〇re_channeis) of the nanometer pore layer, as shown in the second figure (eight) As shown in the figure, a high-density nc_Si quantum dot array can be synthesized in the nanopore dioxide layer. Finally, indium tin oxide (IT0) is deposited on the nanoporous ceria layer. a layer, and then an electrical connection point is respectively disposed on the surface of the p-type germanium substrate and the indium tin oxide layer) UV detector into -Μ〇§ structure, such as a second (B) of FIG. Since all processes are performed in a high vacuum environment, the quality and characteristics of the nc-Si/Si〇2 interface can be controlled and produced. 1287628 The MOS structure was analyzed by a transmission electron microscope (TEM) for the cross section of the nanoporous ceria layer, and the resulting transmission electron microscope image was as shown in the third figure. Referring to the third figure, it is a transmission electron microscope image showing a cross section of a nano-hole with a nc-Si nanopore. The illustration in the upper left corner of the third figure shows a distinct lattice fringes, which indicates that the nc-Si has a high crystalline quality, and the size of the quantum dots formed by n (>Si is about 2 to 5 nm). , its density < 2. 5χ1〇18 cm3.

Example 2 In the same manner as in Example 1, except that the nanopore dioxide layer was converted into nc_Ge, a similar MOS structure was prepared. The depth profiling measurement of the nanoporous silica dioxide layer of the MOS structure obtained in the first embodiment was carried out by secondary ion mass spectroscopy (SIMS), and the results were shown in the fourth.

Figure. Refer to the fourth®, according to the analysis results of SIMS, and with the analysis of the transmission electron microscopy image, you can also form quantum dots with a size of 2~_5nm by riding ne_Ge, and its density can reach 2 Qxi(^w This oyster does not have a similar UV-detector in the third hole of the nano-porous oxidized layer towel, to 420 nm with 420 nm and to detect it with/without 420 nm and 632. Nm is irradiated with the light of the J 632 nm laser beam worn in the first embodiment, and the current is electrically dominant under the illumination of the light of 14 1287628 laser, and the obtained result is shown in the fifth figure. The results obtained by the fifth figure show that When the light is not illuminated, the current is less than the current of the forward bias as the element feels a resistance in the reverse bias. The H77 I / 妁11 is illuminated, due to the energy gap structure. The light-sensing layer pole (4) catches a positive charge and causes a positive internal electric field, so that under the reverse bias, a large amount of electrons accumulated in the (four) material/nano hole dioxide (four)

By passing through a high-density quantum dot to the positive electrode, a significant current gain is caused, causing the current to be greater than the current at the forward bias. From this result, it can be seen that the sensing layer of the present invention can have a very high photoelectric response in the blue light and visible light bands, and an extremely high π sang ratio. Embodiment 4 The nanopore dioxide layer in the MOS structure prepared in the first embodiment corresponds to excitation light of different wavelengths to the underside, and the obtained photoelectric response result is shown in the sixth figure. The figure shows that the photoelectric response spectrum covers the ultraviolet to visible light band. It is known that this-composite (4) has a very wide (350-700 nm) due to the complex bonding structure between the nano-quantum dots and the nano-fine silica dioxide layer. The optical band's and the photoelectric response® spectrum cover the visible light band of the ultraviolet light because of the band gap of the blue light band. The figure shows that the element has a photoexcitation current of G.9A/W under the illumination of 590 nm light, in ultraviolet light. The band has a photoexcitation current of about 0.2-0.4 A/W. The difference in photoexcitation current in the spectrogram is mainly due to the absorption efficiency of the component to the light wave and the recombination of the carrier at the time of light irradiation. The component exhibits strong rectifying characteristics regardless of the illumination of any wavelength of light. In the fifth embodiment, the ultraviolet light detector prepared in the first embodiment is irradiated with pulsed laser light of different wave hands (420 nm, 540 nm, 580 nm and 640 nm) to detect the photoelectricity of various wavelengths. The response speed is shown in the seventh graph. The results obtained in the seventh graph show that the ultraviolet light detector has an extremely fast photoelectric response speed to the ultraviolet-blue light band. Example 6 The ultraviolet photodetector prepared in Example 1 was subjected to a current-time curve at 2 mW, 420 nm light irradiation and a 5 V bias, and the results are shown in the eighth figure. ""' The results obtained in Figure 8 show that the UV detector does not cause any significant change in its signal due to long-term exposure to strong light.曰 [Simplified description of the diagram] The first diagram is a schematic diagram of the steps of forming quantum dots of nc-Si (or nc_Ge) in the nanopore dioxide by using pAALD; the second diagram (4) is the second diagram (8) A schematic view showing the detailed structure of the nanopore dioxide layer in the M〇s structure; (8) is a cross-sectional view of the embodiment of the MOS structure made of the layer of the present invention - 16 1287628; -Si nano-holes, a layer of SiO2, and a transmission electron microscope (TEM) image, in which the upper left corner is a further enlarged image; the fourth image is the growth of the quantum dot, the nano The SIMS analysis results of the pores of the pores of the pores of the pores; (3) 'The fifth figure is the analysis of the current and voltage characteristics of the ultraviolet-visible light detector of the invention under the irradiation of 632 ηηι and 々420 nm laser light. Temperature response to different wavelengths of excitation light, its photoelectric response measurement results; 3 The seventh figure is the ultraviolet-visible light detector of the present invention, different wavelengths of pulse-thunder-lighting, the results of photoelectric response speed analysis The picture shows the UV-visible light detector of the present invention to 2mw, under the current irradiated with light emitted ⑽ ® _ 5V bias time characteristic curve analysis of FIG. [Main component symbol description] 10 nm hole dioxide dioxide dream 12 hole 14 inner wall 16 hydrogen plasma 18 neutron point nucleation position 20 decane 22 quantum dot 24 quantum dot array 1287628, 26 P type 矽 substrate - 28 nm hole dioxide oxidation矽 30 indium tin oxide (ITO) layer 32 electrical connection point 34 electrical connection point - 36 quantum dots. 38 channel inner wall

18

Claims (1)

The method of claim 1, wherein the method of forming the high-density quantum dot array on the inner wall of the hole in the nanoporous ceria is pulsed. High-density plasma-assisted atomic layer chemical vapor deposition. 8. The ultraviolet-visible light detector as described in the scope of the patent application, wherein the ultraviolet light and visible light wavelength range refers to a light wavelength of 32 〇 _7 〇〇 nm. 9. An ultraviolet-visible light detector comprising: a stone substrate; a sensing layer formed on the germanium substrate; and an indium tin oxide (indhjm tin (10), for example, ITO) formed on the sensing layer, wherein the subtractive system is formed by the nanopore dioxide (four) a high-density quantum dot array of naphthalene crystals on the inner wall of the channel in the methane hole, and the nanocrystallite is a nanocrystallite or a nanocrystallite, and the sensing layer is in the absorption purple material. An optical response is produced after the wavelength of the visible light source. 10. The ultraviolet-visible light detector of claim 9 in the scope of the application, wherein the density of the rice crystallites is 1Χ1017~5xl0i8cm3. The diameter of the crystal in the 3 hai is not 2 nm. 12. The ultraviolet-visible fine detector described in item 9 is formed by stacking the nanocrystallites in three dimensions: the diameter of the hole in the nanometer + hole dioxotomy in nm is 2~iq, 20 1287628. The ultraviolet-visible light detector of claim 9, wherein the method for forming the high-density quantum dot array on the inner wall of the pore in the nanoporous ceria is Ion implantation (implantati〇n), oxidative precipitation, conventional chemical deposition (CVD), high-intensity inductively coupled plasma (ICP) chemical vapor deposition (CVD), and plasma-enhanced chemical vapor deposition (plasma enhanced CVD, PECVD) or plasma assist atomic layer chemical vapor deposition (PAALD). The ultraviolet-visible light detector according to claim 9, wherein the method of pulsing the high-density quantum into the inner wall of the hole in the nano-hole of the nano-hole is a pulse High-density (four) auxiliary atomic layer chemical vapor deposition method. 16. The ultraviolet light-visible light detector according to claim 9, wherein the outer wavelength range of the visible light and the visible light wavelength range is 32Q_7_m.