JP5374643B2 - Photodetector capable of detecting long wavelength radiation - Google Patents

Abstract

A photodetector capable of detecting long wavelength radiation, comprising a source disposed on a proximal end of an insulation layer; a drain disposed on a distal end of the insulation layer; at least one nano-assembly coupling the source and the drain between the proximal and distal ends; and at least two surface plasmon waveguides positioned between the source and the drain and juxtaposed to the at least one nano-assembly in a longitudinal direction of the at least one nano-assembly, wherein one of the at least two surface plasmon waveguides is positioned along a first side of the at least one nano-assembly, and another of the at least two surface plasmon waveguides is positioned along a second side of the at least one nano-assembly that is opposite the first side.

Description

  The present invention relates to an apparatus capable of detecting long-wavelength radiation and a technique for detecting long-wavelength radiation.

  There are several useful applications for detecting long wavelength radiation at room temperature, including military and civilian applications. For example, photodetectors for detecting long-wavelength radiation can be used as medical devices, missile tracking devices, or in drug enforcement. As nanotechnology with the design of nanoscale electronics including optical devices and photodetectors (i.e. structures having a size of about 100 nm or less) continues to evolve, nanotechnology advances can be improved with improved efficiency and Because of its detection capability, it is believed that it can be applied to the design of such nanoscale electronics (ie, optical devices and photodetectors).

  An apparatus capable of detecting long wavelength radiation (eg, infrared spectrum light) and techniques for detecting long wavelength radiation (eg, infrared spectrum light) are provided. In one embodiment, a photodetector capable of detecting long wavelength radiation includes a source disposed on the proximal end, a drain disposed on the distal end, and between the proximal and distal ends. At least one nanoassembly coupling the source and drain, comprising at least two surface plasmon waveguides disposed between the source and drain and juxtaposed with the at least one nanoassembly in a longitudinal direction of the at least one nanoassembly; One of the at least two surface plasmon waveguides is disposed along a first side of the at least one nanoassembly, and the other of the at least two surface plasmon waveguides is at least opposite the first side. Arranged along the second side of one nanoassembly.

  In another embodiment, the photodetector is positioned proximate to the at least one nanoassembly and the at least two surface plasmon waveguides and extends substantially parallel to at least one of the source and drain. A transparent gate arranged as described above may be further provided.

  The foregoing description is exemplary only and is not intended to be limiting in any way. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and by reference to the following detailed description.

1 is a perspective view of an exemplary embodiment of a photodetector. FIG. FIG. 4 shows a spectrum of long wavelength radiation that can be detected in an exemplary embodiment. 2 is a conceptual diagram of an exemplary embodiment of an intersubband transition within the conduction band of a nanoassembly. FIG. 6 is a graph illustrating the electric field strength of photons confined within the interface of an exemplary embodiment of a photodetector. FIG. 6 is a perspective view of another exemplary embodiment of a photodetector. FIG. 4 illustrates a visible light spectrum that can be detected in an exemplary embodiment. 1 is a conceptual diagram of an exemplary embodiment of an intersubband transition in a nanoassembly. FIG. FIG. 3 is an illustration of an exemplary embodiment of a structure of a ZnO nanobelt. FIG. 6 is an illustration of an exemplary embodiment of an energy band diagram of a photodetector nanoassembly. FIG. 2 is a cross-sectional view of an exemplary embodiment of the photodetector of FIG. FIG. 6 is a cross-sectional view of the exemplary embodiment of the photodetector of FIG. FIG. 6 is a perspective view of an exemplary embodiment of a photodetector having a nanoassembly remote from an SP waveguide. It is sectional drawing of the photodetector of FIG. FIG. 6 is a cross-sectional view of another exemplary embodiment of a photodetector having a nanoassembly in contact with an SP waveguide. FIG. 3 is a perspective view of an exemplary embodiment of a photodetector for detecting three different spectral ranges. FIG. 16 is a cross-sectional view of the exemplary embodiment of the photodetector shown in FIG. FIG. 6 is a cross-sectional view of another exemplary embodiment of a photodetector having a nanoassembly in contact with an SP waveguide. 3 is a flow diagram of an exemplary embodiment of a method for implementing a photodetector that detects long wavelength radiation. 2 is a flow diagram of an exemplary embodiment of a method for implementing an SP waveguide. FIG. 20 illustrates the method shown in FIG. 19. FIG. 20 illustrates the method shown in FIG. 19. FIG. 20 illustrates the method shown in FIG. 19.

  In the following detailed description, reference is made to the accompanying drawings, which form a part hereof. Similar symbols in the drawings typically indicate similar components, unless context dictates otherwise. The illustrative embodiments described in the detailed description, drawings, and claims are not meant to be limiting. Other embodiments may be utilized and other modifications may be made without departing from the spirit or scope of the subject matter presented herein. Aspects of the present disclosure as generally described herein and illustrated in the figures can be arranged, replaced, combined, separated, and designed in a variety of different configurations, all explicitly described herein. It will be readily understood that it is intended.

  FIG. 1 is a perspective view of an exemplary embodiment of a photodetector 100 that can be used to detect long wavelength radiation (eg, infrared spectrum light). As shown in FIG. 1, the photodetector 100 can be formed on a laminated structure of a substrate 110 and an insulating layer 120. Further, the nanoassembly 130, the surface plasmon waveguide (hereinafter referred to as “SP waveguide”) 140, the source 150, and the drain 160 may be disposed on the insulating layer 120. In one embodiment, at least two SP waveguides 140 are disposed between a source 150 and a drain 160 that are respectively disposed on the proximal and distal ends of the stacked structure. For example, the source 150 and the drain 160 may be disposed on the proximal end and the distal end of the insulating layer 120, respectively. Upon receiving incident light, nanoassembly 130 operates as a channel interconnecting source 150 and drain 160 so that a predetermined current flows in an external circuit (not shown) coupled to photodetector 100. sell.

  The SP waveguide 140 may be disposed between the source 150 and the drain 160 and juxtaposed with the nanoassembly 130 in the longitudinal direction of the nanoassembly 130. In addition, one SP waveguide 140 is disposed along the first side of the nanoassembly 130 and the other SP waveguide 140 is along the second side of the nanoassembly 130 opposite the first side. Disposed and defines at least some space between the SP waveguide 140 and the nanoassembly 130, which may range from a few nanometers to thousands of nanometers. As further described below in connection with FIG. 4, the interleaving of nanoassemblies 130 and SP waveguides 140 constitutes an interface for receiving photons from incident light, thereby allowing photons to pass through SP waveguides 140. Can be effectively confined around the nanoassembly 130 between them. In one embodiment, the space between the SP waveguide 140 and the nanoassembly 130 can be filled with a dielectric such as porcelain (ceramic), mica, glass, plastic, various metal oxides, or air. Can include any type of dielectric. The SP waveguide 140 may include any type of metal material such as Ag, Al, Au, Ni, Ti.

  In one embodiment, the source 150 and the drain 160 can include a metal, silicide, or a semiconductor such as silicon, germanium, a II-VI semiconductor compound, or a III-V semiconductor compound. Examples of applicable II-VI group semiconductor compounds include CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, HgS, HgSe, HgTe, CdZnSe, CdSSe, or ZnSSe, and III-V group semiconductor compounds. Examples include GaAs, InP, GaP, AlGaAs, or GaN.

  FIG. 2 shows a spectrum of long wavelength radiation that can be detected by the photodetector 100. As shown in FIG. 2, long wavelength radiation can include radiation of light having a wavelength of several microns or more. Such detection of long wavelength radiation is useful in a variety of applications, including both military and civilian applications. For example, the detection of near-infrared radiation (“NIR” having a wavelength in the range of about 1 μm to about 3 μm) at room temperature can be useful for cancer detection. Detection of room temperature mid-infrared radiation (“MIR” having a wavelength in the range of about 3 μm to about 5 μm) can be used in many military applications such as missile tracking devices. Detection of infrared radiation at room temperature (“IR” having a wavelength in the range of about 8 μm to about 12 μm) can be utilized in both military and civilian applications for applications such as human body detection. Furthermore, the detection of far-infrared radiation at room temperature (“FIR” having a wavelength greater than several tens of μm) can be used for drug enforcement.

  FIG. 3 is a conceptual diagram of an exemplary embodiment of an intersubband transition within the conduction band of nanoassembly 130. Photodetector 100 can detect long wavelength radiation by using intersubband transitions within the conduction band of nanoassembly 130. As shown in FIG. 3, the conduction band 302 of the nanoassembly 130 may have several intersubbands 304 and 306. When a photon having an energy corresponding to the intersubband transition energy gap between the intersubbands 304 and 306 strikes the conduction band 302, the electrons in the conduction band 302 become lower intersubband 304 (ie, the base State) to the upper inter-subband 306, and current can be passed through the photodetector 100. Photons can have energies in the range of a few meV to a few hundred meV.

  FIG. 4 is a graph illustrating the electric field strength of photons confined within the interface of the photodetector 100 with the nanoassembly 130 disposed between the SP waveguide 140 and the SP waveguide 140. In FIG. 4, the region 402 corresponding to the SP waveguide 140 includes a metal material, while the region 404 corresponding to the nanoassembly 130 includes a dielectric, as also shown in FIG. Further, the x axis indicates the horizontal position of the nanoassembly 130 and the SP waveguide 140, while the y axis indicates the electric field strength. The graph shown in FIG. 4 shows that a substantial portion of the light field generated by incident light (ie, photons) is confined within region 404. The electric field confined between the region 402 and the region 404 can be described by Equation 1 shown below.

式中、Ｄ_x__metal及びＤ_x__dielectricは、それぞれ、領域４０２（ＳＰ導波路１４０内に含まれる金属材料に対応する）及び領域４０４（ナノアセンブリ１３０内に含まれる誘電体に対応する）内の電束密度であり、Ｅ_x__metal及びＥ_x__dielectricは、それぞれ、領域４０２及び領域４０４内の電界であり、ε_metal及びε_dielectricは、それぞれ、領域４０２及び領域４０４の誘電率である。

Wherein, D _x _ _metal and D _x _ _Dielectric, respectively, (corresponding to the metal material contained in the SP waveguide 140) region 402 (corresponding to the dielectric material contained in the nano-assembly 130) and region 404 And E _x _ _metal and E _x _ _dielectric are the electric fields in regions 402 and 404, respectively, and ε _metal and ε _dielectric are the dielectric constants of regions 402 and 404, respectively. is there.

In Equation 1, the value of ε _metal is much larger than the value of ε _dielectric so that E _{x _dielectric} is larger than E _x _ _metal , which means that a significant portion of the light field is confined within region 404 Means.

Referring to FIG. 4 and Equation 1, the electric field of incident photons confined between SP waveguides 140 (ie, nanoassemblies 130) is determined by the dielectric constant of SP waveguide 140 and the nanoassembly 130 (and / or between SP waveguides 140). It can be seen that it is substantially proportional to the ratio of the dielectric constant of the dielectric material filled in. Thus, the desired confinement of the electric field is suitable for SP waveguide 140 and / or nanoassembly 130, even when the width of nanoassembly 130 and / or the height of SP waveguide 140 is less than the wavelength of the incident photon. It can be obtained by selecting the material (s) with a dielectric constant. In such an embodiment, the SP waveguide 140 can be made from one or more different types of metals. As shown in Equation 2 below, the dielectric constant ε _metal of a _metal is a function of frequency, so the type of metal used depends on the frequency of photons detected by the photodetector 100. Yes. The type of metal can be selected based on the wavelength detected by the photodetector 100. In one embodiment, compounds such as Ag, Al, Au, Ni, Ti, or other suitable metals can be selected for long wavelength detection.

式中、記号ω_pは、自由伝導電子の集団振動のプラズマ振動数を表す。

In the formula, the symbol ω _p represents the plasma frequency of the collective vibration of free conduction electrons.

  FIG. 5 is a perspective view of another exemplary embodiment of a photodetector 500 that can be used to detect the visible light spectrum. The photodetector 500 is substantially identical to the photodetector 100 except that a transparent gate 180 can be formed above or substantially on top of the nanoassembly 130 and SP waveguide 140. An insulating layer 170 can be disposed between the transparent gate 180 and the nanoassembly 130 (or SP waveguide 140). By using the support member 175, it is shown in FIG. 5 that the insulating layer 170 and the transparent gate 180 are disposed above the nanoassembly 130 and the SP waveguide 140. Any other suitable structure can be used to place the insulating layer 170 and the transparent gate 180 on the waveguide 140. The transparent gate 180 can be disposed substantially perpendicular to the nanoassembly 130 and SP 140 and substantially parallel to the long direction of the source 150 or drain 160. The transparent gate 180 may be disposed proximate to the at least one nanoassembly 130 and the at least two SP waveguides 140 so as to extend substantially parallel to at least one of the source 150 and the drain 160. The transparent gate 180 serves to reduce the internal field of the nanoassembly 130 caused by spontaneous polarization (as described in further detail below) of the nanoassembly 130.

  FIG. 6 illustrates the range of wavelengths in the visible light spectrum that can be detected by the photodetector 500. As shown in FIG. 6, the visible light spectrum corresponds to a wavelength band from about 380 to about 780 nm (eg, corresponding to a spectrum of colors from purple to red). For example, visible blue light, visible green light, and visible red light have wavelengths of about 450 nm, about 520 nm, and about 650 nm. Photodetector 500 can detect the visible light spectrum by measuring the intersubband transition of electrons in nanoassembly 130.

  FIG. 7 is a conceptual diagram of an exemplary embodiment of an interband (ie, band to band) transition of electrons between valence band 702 and conduction band 704 in nanoassembly 130. When a photon having an energy corresponding to the band gap energy between the valence band 702 and the conduction band 704 collides with the nanoassembly 130, the electrons 706 in the valence band 702 can transition to the conduction band 704. Current flows in the photodetector 500 due to the transition of the electrons 706 from the valence band 702 to the conduction band 704 (band-to-band transition).

  FIG. 8 illustrates the basic structure of a ZnO nanobelt 800 that may have a width of about 100 nm and a thickness of about 10 nm. As shown in FIG. 8, the side surface of the ZnO nanobelt 800 may include a (0001) polar surface. In this case, spontaneous polarization is induced on the ZnO nanobelt 800 by positive and negative ionic charges on the (0001) polar surface. As a result, there is an internal field (E) formed along the (0001) direction, which minimizes the total contribution to energy due to spontaneous polarization and lowers the optical transition probability. As shown in FIG. 5, a transparent gate 180 is provided to correct the internal field (E) in the nanoassembly 130 by being placed above or substantially on top of the nanoassembly 130. Can be done. In one embodiment, the insulating layer 170 can be disposed between the nanoassembly 130 (and / or the SP waveguide 140) and the transparent gate 180.

  FIG. 9 illustrates an exemplary embodiment of an energy band diagram of the nanoassembly 130 of the photodetector 500. The energy band diagram in the left part of FIG. 9 shows the conduction band in the nanoassembly 130 that is obtained when the transparent gate 180 is not present (ie not present) in the photodetector 500. Furthermore, the energy band diagram in the right portion of FIG. 9 shows the conduction band in the nanoassembly 130 that is obtained when the transparent gate 180 is present in (ie, is in) the photodetector 500. Comparing the two figures to each other, the slope 910 of the energy band diagram (ie, the lower bound of the conduction band) is smaller when the transparent gate 180 is included in the photodetector 500, which is a result of spontaneous polarization. This is because the resulting internal field in the nanoassembly 130 is weakened by applying a reverse voltage to the transparent gate 180 above or substantially above the nanoassembly 130. Applying a reverse voltage in the opposite direction to the direction of the internal field (E) in the nanoassembly 130 from an external circuit (not shown) to the transparent gate 180, thereby defeating the internal field of the nanoassembly 130 Can do.

  FIG. 10 shows a cross-sectional view of the photodetector 100 taken along the line A-A ′ of FIG. 1. In FIG. 10, the cross-sectional dimensions of the nanoassembly 130 are on a nanometer scale. In some embodiments, nanoassembly 130 has a width ranging from about 10 nm to about 500 nm, such as about 10 nm, about 20 nm, about 50 nm, about 100 nm, about 200 nm, or about 500 nm, and about 0.5 μm, about It can have a length ranging from about 0.5 μm to about 5 μm, such as 1 μm, about 2 μm, about 3 μm, about 4 μm, or about 5 μm. In other embodiments, the nanoassembly 130 may have a width in the range from about 30 nm to about 300 nm, a width / thickness ratio in the range from about 5 to about 10, and a length up to a few millimeters. it can. The width and length of the nanoassembly 130 can vary substantially in various embodiments. The nanoassembly 130 can be a nanowire, a nanobelt, a nanorod, or the like.

  In one embodiment, nanoassembly 130 may include a semiconductor material (hereinafter referred to as “nanomaterial”) such as Si, InAs, or ZnO. The material of the nanoassembly 130 can be selected depending on the range of emission wavelengths to be detected. Table 1 shows the characteristics of the nanomaterial (ie, the energy gap between subbands and the wavelength to be detected).

表１を参照すると、ナノ材料ＺｎＯ、Ｓｉ、及びＩｎＡｓを使用して検出することができる波長は、それぞれ、約２５μｍ、約１２μｍ、及び約４．５μｍであることがわかる。これらの波長に基づき、ナノ材料ＺｎＯ、Ｓｉ、及びＩｎＡｓは、それぞれ、ＦＩＲ、ＩＲ、及びＭＩＲを検出するのに適している。他の適切な（複数可）ナノ材料も、所望の波長放射を検出するために光検出器１００に使用することができる。

Referring to Table 1, it can be seen that the wavelengths that can be detected using the nanomaterials ZnO, Si, and InAs are about 25 μm, about 12 μm, and about 4.5 μm, respectively. Based on these wavelengths, the nanomaterials ZnO, Si, and InAs are suitable for detecting FIR, IR, and MIR, respectively. Other suitable nanomaterial (s) can also be used in the photodetector 100 to detect the desired wavelength radiation.

  In some embodiments, the thickness of SP waveguide 140 ranges from about 2 μm to about 3 μm to allow fine confinement of photons. Although the SP waveguide 140 is shown in FIGS. 1 and 5 as having a rectangular shape, the shape and dimensions of the SP waveguide 140 can vary depending on the respective application. For example, each of the SP waveguides 140 may take the form of a slab, rib, or ridge for use with the photodetector 100 or 500.

  FIG. 11 shows a cross-sectional view of the photodetector 500 taken along the line A-A ′ of FIG. 5. In one embodiment, the nanoassembly 130 can be made from III-V and II-VI semiconductor materials. Table 2 below shows examples of III-V and II-VI group semiconductor materials with corresponding band gap energy (eV), lattice constant (a axis) in angstrom (Å) units, and crystal structures. ing.

ナノアセンブリ１３０のナノ材料は、検出すべき可視光スペクトルの範囲に応じて選択することができる。一実施形態では、ナノアセンブリ１３０は、ＣｄとＺｎＳとの合金であるＣｄＺｎＳを含むことができる。ＣｄＳ及びＺｎＳは、直接バンドギャップ半導体材料であり、六方晶構造を有する。Ｃｄ_xＺｎ_1-xＳのバンドギャップエネルギーは、以下の式３によって決定されうる。
［式３］
Ｅ_g＝３．７２３−１．２４１ｘ
ｘ＝０．７である場合、ＣｄＺｎＳのバンドギャップエネルギーＥ_gは２．８５３ｅＶであり、これは、約４３５ｎｍの波長を有する光子（青色スペクトル光）のエネルギーに対応する。一実施形態では、ナノアセンブリ１３０が、Ｃｄ_xＺｎ_1-xＳ（０≦ｘ≦０．５）を含む場合、光検出器５００は、青色スペクトルを検出するのに適しうる。

The nanomaterial of the nanoassembly 130 can be selected depending on the range of visible light spectrum to be detected. In one embodiment, the nanoassembly 130 can include CdZnS, which is an alloy of Cd and ZnS. CdS and ZnS are direct band gap semiconductor materials and have a hexagonal crystal structure. The band gap energy of Cd _x Zn _1-x S can be determined by the following Equation 3.
[Formula 3]
E _g = 3.723-1.241x
When x = 0.7, the band gap energy E _g of CdZnS is 2.853 eV, which corresponds to the energy of a photon (blue spectrum light) having a wavelength of about 435 nm. In one embodiment, if the nanoassembly 130 includes Cd _x Zn _1-x S (0 ≦ x ≦ 0.5), the photodetector 500 may be suitable for detecting the blue spectrum.

In another embodiment, the nanoassembly 130 can include CdSSe. CdSSe is a direct band gap semiconductor material with CdS, and is an alloy with CdSe having a hexagonal crystal structure. The band gap energy of CdSe _x S _1-x can be determined by Equation 4 below.
[Formula 4]
E _g = 2.482-0.75x
When x = 0.15, the band gap energy E _g of CdSSe is 2.37 eV, which corresponds to the energy of a photon (green spectrum light) having a wavelength of about 520 nm, and x = 0.7 In some cases, the band gap energy E _g of CdSSe is 1.957 eV, which corresponds to the energy of a photon (red spectrum light) having a wavelength of about 633 nm. That is, the nanoassembly 130 containing CdSSe may be suitable for detecting both green and red spectrum light. In one embodiment, if the nanoassembly 130 includes CdSe _x S _1-x (0 ≦ x ≦ 0.4), the photodetector 500 may be suitable for detecting the green spectrum. In one embodiment, if the nanoassembly 130 includes CdSe _x S _1-x (0.6 ≦ x ≦ 1.0), the photodetector 500 may be suitable for detecting the red spectrum. Other suitable nanomaterial (s) can also be used in the photodetector 500 to detect the desired spectral range.

  FIG. 12 shows a perspective view of an exemplary embodiment of a photodetector 1200 having a nanoassembly remote from the SP waveguide. Referring to FIG. 12, it can be seen that the photodetector 1200 comprises three nanoassemblies 132, 134, and 136 and four SP waveguides 142, 144, 146, and 148. The SP waveguides 144 and 146 can be placed between the nanoassemblies 132, 134, and 136 to form an alternating arrangement of the nanoassemblies 132, 134, and 136 and SP waveguides 144 and 146. In one embodiment, nanoassemblies 132, 134, and 136 can each include the same type of nanomaterial. In this case, the photodetector 1200 may be suitable for detecting one specific wavelength band corresponding to the nanomaterial. By using nanoassemblies 132, 134, and 136, the photodetector 1200 can quickly detect radiation of the desired wavelength while collecting more photons from the incident light. In another embodiment, each of the nanoassemblies 132, 134, and 136 can include a different type of nanomaterial. In an exemplary embodiment where the nanoassemblies 132, 134, and 136 include different nanomaterials (eg, ZnO, Si, and InAs, respectively), the photodetector 1200 has different wavelength bands (eg, FIR, IR, MIR). May be suitable for detecting. In this case, a separate drain may be provided for each of the nanoassemblies 132, 134, and 136 so that external circuitry connected to each drain can detect different wavelength bands.

FIG. 13 shows a cross-sectional view of the photodetector 1200 taken along the line AA ′ of FIG. Referring to FIG. 13, the photodetector 1200 has a stacked structure in which a substrate 110, an insulating layer 120, nano-assemblies 132, 134, and 136 (or SP waveguides 142, 144, 146, and 148) are sequentially stacked. It can be seen that In one embodiment, the substrate 110 can include glass, silicon, or quartz. The insulating layer 120 or 170 is made of silicon dioxide (SiO ₂ ), fluorosilicate glass (FSG), tetraethyl orthosilicate (TEOS) oxide, silanol (SiOH), flowable oxide (FOx), bottom antireflection film (BARC), anti-reflective coating (ARC), photoresist (PR), almost frictionless carbon (NFC), silicon carbide (SiC), silicon oxycarbide (SiOC), and / or carbon doped silicon oxide (SiCOH) May be included. While nanoassemblies 132, 134, and 136 can include nanomaterials such as Si, InAs, or ZnO, SP waveguide 140 can be any type of metal that includes Ag, Al, Au, Ni, or Ti. Material can be included. In FIG. 13, nanoassemblies 132, 134, and 136 are interleaved with SP waveguides 142, 144, 146, and 148 on insulating layer 120, and each nanoassembly 132, 134, and 136 is adjacent to it. Apart from the SP waveguides 142, 144, 146 and 148.

  FIG. 14 shows a cross-sectional view of an exemplary embodiment of a photodetector 1400 having a nanoassembly in contact with an SP waveguide. Referring to FIG. 14, it can be seen that the photodetector 1400 comprises nanoassemblies 132, 134, and 136 that are interleaved and in contact with the SP waveguides 142, 144, 146, and 148. The alternating arrangement of nanoassemblies 132, 134, and 136 and SP waveguides 142, 144, 146, and 148 as shown in FIG. 14 constitutes an interface for receiving incident light, where dielectrics The medium is sandwiched between metal materials.

FIG. 15 shows a perspective view of an exemplary embodiment of a photodetector 1500 having a nanoassembly remote from the SP waveguide. The photodetector 1500 comprises three nanoassemblies 132, 134, and 136 and four SP waveguides 142, 144, 146, and 148. The SP waveguides 144 and 146 can be placed between the nanoassemblies 132, 134, and 136 to form an alternating arrangement of the nanoassemblies 132, 134, and 136 and SP waveguides 144 and 146. Further, the drains 162, 164, and 166 are separately disposed for each of the nanoassemblies 132, 134, and 136. In one embodiment, each of drains 162, 164, and 166 is routed to a different external circuit (not shown), and a predetermined current through each of nanoassemblies 132, 134, and 136 is within each external circuit (not shown). Can be connected to be detected. In one embodiment, nanoassemblies 132, 134, and 136 can each include different nanomaterials. For example, nanoassemblies 132, 134, and 136 are Cd _x Zn _1-x S (0.5 ≦ x ≦ 1.0), CdSe _x S _1-x (0 ≦ x ≦ 0.4), and CdSe _x S _1-x (0.6 ≦ x ≦ 1.0) may be included. In this case, the photodetector 1500 may be suitable for detecting spectra of different colors, such as light in the blue, green, or red spectrum.

  FIG. 16 shows a cross-sectional view of the photodetector 1500 taken along the line A-A ′ of FIG. 15. Referring to FIG. 16, photodetector 1500 includes substrate 110, insulating layer 120, nanoassemblies 132, 134, and 136 (or SP waveguides 142, 144, 146, and 148), insulating layer 170, and a transparent gate. It can be seen that 180 has a stacked structure in which the layers are sequentially stacked. Substrate 110, insulating layers 120 and 170, source 150 and drain 160 may comprise the same materials used in FIG. The nanoassemblies 132, 134, and 136 can include nanomaterials such as CdSe, CdS, ZnS, MgSe, or ZnS, while the SP waveguide 140 and the transparent gate 180 can be Ag, Al, Au, Ni, or Any type of metallic material including Ti can be included. In FIG. 16, nanoassemblies 132, 134, and 136 are interleaved with SP waveguides 142, 144, 146, and 148 on insulating layer 120, and each of nanoassemblies 132, 134, and 136 is adjacent to each other. Apart from the SP waveguides 142, 144, 146 and 148.

  FIG. 17 illustrates a cross-sectional view of an exemplary embodiment of a photodetector 1700 having a nanoassembly in contact with an SP waveguide. Referring to FIG. 17, it can be seen that the photodetector 1700 comprises nanoassemblies 132, 134, and 136 that are interleaved and in contact with the SP waveguides 142, 144, 146, and 148. The alternating arrangement of nanoassemblies 132, 134, and 136 and SP waveguides 142, 144, 146, and 148 as shown in FIG. 17 constitutes an interface for receiving incident light, where dielectrics The medium is sandwiched between metal materials.

  FIG. 18 illustrates a flowchart of an exemplary embodiment of a method for realizing a photodetector that detects long wavelength radiation. At block 1810, the source and drain are configured and can be manufactured using any of a variety of well-known manufacturing techniques such as chemical vapor deposition, photolithography, or etching techniques. At block 1820, the source and drain are coupled by at least one nanoassembly that can be grown between the source and drain using any of a variety of suitable techniques, such as epitaxial growth techniques, or Amorphous deposition is performed by a suitable deposition technique. Exemplary techniques for applying the coating include molecular beam epitaxy (MBE), metal organic chemical vapor deposition (MOCVD), chemical vapor deposition (CVD), or plasma CVD (PECVD).

  At a block 1830, one of the SP waveguides is disposed along a first side of the nanoassembly, and the other of the SP waveguides is disposed along a second side of the nanoassembly opposite the first side. And an SP waveguide, juxtaposed with the nanoassembly in the longitudinal direction of the nanoassembly. FIG. 19 is a flow diagram of an exemplary embodiment of a method for implementing an SP waveguide. 10A-20C are a series of diagrams illustrating the method shown in FIG. Referring to FIG. 19, at block 1910, it can be seen that a first antireflective layer 2010 is formed on the photon receiving surface 2012 on the insulating layer 120, as shown in FIG. 20A. In one embodiment, photon receiving surface 2012 may be part of the top surface of insulating layer 120. At block 1020, as shown in FIG. 20B, the first anti-reflective layer 2010 is patterned to define two elongated holes 2022 and 2024 therein. For example, the first antireflective layer 2010 may be patterned by first forming a photomask with a pattern corresponding to the two elongated holes 2022 and 2024, etching the first antireflective layer 2010, and then removing the photomask. Can be formed. At block 1930, as shown in FIG. 20C, metal is deposited into two elongated holes 2022 and 2024 (shown in FIG. 20B) to place two SP waveguides 2042 and 2044 in the middle, respectively. To form. Such deposition can be performed, for example, by using suitable masking and deposition techniques known in the art. The SP waveguides 2042 and 2044 can be constructed by using any of a variety of well-known techniques such as metal etching.

  Referring again to FIG. 18, after placing the SP waveguide, it can be seen at block 1840 that the transparent gate can be placed above or substantially on top of the nanoassembly and the at least two SP waveguides. In one exemplary embodiment, an insulating layer can be placed over the nanoassembly and SP waveguide prior to placing the transparent gate. At block 1850, the transparent gate is further disposed proximate to the at least one nanoassembly and the at least two SP waveguides so as to extend substantially parallel to at least one of the source and drain.

  It will be appreciated that with respect to this and other processes and the methods disclosed herein, the functions performed by these processes and methods can be performed in a different order. Furthermore, the outlined steps and operations are presented by way of example only, and some of these steps and operations may be optional, without departing from the essence of the disclosed embodiments, or It can be combined into fewer steps and actions, or can be expanded with additional steps and actions.

  The present disclosure is not limited with respect to the particular embodiments described in this application, which are intended to illustrate various aspects. Many modifications and changes may be made without departing from the spirit and scope of this disclosure. Functionally equivalent methods and apparatus within the scope of this disclosure will be apparent in addition to those listed herein. Such modifications and variations are intended to fall within the scope of the appended claims. This disclosure is to be limited only with respect to the appended claims, along with the full scope of equivalents to which the appended claims are directed. It is to be understood that this disclosure is not limited to particular methods, reagents, compounds, compositions, or biological systems that can, of course, vary. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting.

  With respect to the use of substantially plural and / or singular terms herein, the plural may be changed to singular and / or singular to plural as appropriate depending on the context and / or application. It will be understood that Various singular / plural permutations may be expressly set forth herein for sake of clarity.

  In general, the terminology used herein, and specifically used in the appended claims (eg, the body of the appended claims), is the phrase “unconstrained” (eg, “includes”). Should be construed as "including but not limited to" and the phrase "having" should be construed as "having at least" and the phrase "including" includes "but not limited to" It should be further understood that it is generally intended to be interpreted as “. Where a specific number of claim enumerations are intended to be introduced, such intent is explicitly stated in the claims, and in the absence of such enumeration, such intent does not exist Will be further understood. For example, as an aid to understanding, an enumeration of claims may be introduced by including the introductory phrases “at least one” and “one or more” in the appended claims. However, even if such a phrase is used in the original English text, the introduction of the claim enumeration by the indefinite article “a” or “an” may result in the claim being an introductory phrase “one or more” or “at least Embodiments in which a particular claim, including a single claim, and such indefinite article such as “a” or “an”, including such introduced claim list, contain only one such list Should not be construed to mean limited (eg, “a” and / or “an” should be construed to mean “at least one” or “one or more”); The same is true for the use of definite articles used to introduce claim enumeration. In addition, while a specific number of claim enumerations are explicitly recited, it is understood that such enumeration should be interpreted to mean at least the stated number. (For example, when only “two enumerations” are described without any other modifiers, it means at least two enumerations, or two or more enumerations). Further, where similar phrases are used similar to “at least one of A, B, and C, etc.”, generally such syntax is intended to be understood as this conventional phrase. (Eg, “a system having at least one of A, B, and C” includes, but is not limited to, A alone, B alone, C alone, A and B together, A and Including systems having C together, B and C together and / or A, B and C together, etc.). Where an idiomatic phrase similar to “at least one of A, B, or C, etc.” is used, it is generally intended that such syntax be understood as this idiomatic phrase. (Eg, “a system having at least one of A, B, or C” includes, but is not limited to, A alone, B alone, C alone, A and B together, A and C together) Including systems having B, C together, and / or A, B, and C together, etc.). Substantially any disjunctive word and / or phrase that indicates two or more alternative words, whether in the description, in the claims, or in the drawings, is one or more of the words. It will be further understood that it should be understood that the possibility of including either or both words is considered. For example, the phrase “A or B” is understood to include the possibilities of “A” or “B” or “A and B”.

  In addition, if a feature or aspect of the present disclosure is described with respect to a Markush group, it is understood that the present disclosure is thereby described with respect to any individual member or subgroup of members.

  It is further understood that for all purposes, such as with respect to presenting a written specification, all ranges disclosed herein encompass all possible subranges and combinations of those subranges. I will. The listed ranges are sufficient to describe and divide the same range into at least 2 equal parts, 3 equal parts, 4 equal parts, 5 equal parts, 10 equal parts, etc. It is easy to understand that this is the range. As a non-limiting example, each range described herein can be easily divided into a lower third, middle third, upper third, and the like. All phrases such as “maximum to”, “at least”, and similar phrases refer to a range that includes the referenced number and that can then be divided into several subranges as described above. It will also be understood. Finally, it will also be understood that the range includes each individual member. Thus, for example, one group having 1 to 3 cells refers to several groups having 1, 2, or 3 cells. Similarly, a group having 1 to 5 cells refers to several groups having 1, 2, 3, 4, or 5 cells.

  From the foregoing description, various embodiments of the present disclosure have been described herein for purposes of illustration, and various modifications can be made without departing from the scope and spirit of the present disclosure. Will be understood. Accordingly, the various embodiments disclosed herein are not intended to be limiting, with the true scope and spirit being indicated by the following claims.

Claims (36)

A photodetector capable of detecting long-wavelength radiation,
A source disposed on the proximal end of the insulating layer;
A drain disposed on a distal end of the insulating layer;
At least one channel electrically coupling the source and the drain between the proximal end and the distal end;
At least two surface plasmon waveguides disposed between the source and the drain and juxtaposed with the at least one channel in a longitudinal direction of the at least one channel ;
One of the at least two surface plasmon waveguides is disposed along a first side of the at least one channel , and the other of the at least two surface plasmon waveguides is on the first side. Arranged along a second side of the at least one channel facing each other ;
The at least two surface plasmon waveguides confine photons around the at least one channel between the at least two surface plasmon waveguides;
Photo detector. The photodetector of claim 1, wherein at least one of the at least two surface plasmon waveguides is in contact with the at least one channel . The photodetector of claim 1, wherein at least one of the at least two surface plasmon waveguides is separated from the at least one channel by a distance ranging from a few nanometers to a few thousand nanometers. The photodetector of claim 1, wherein the channel is configured to have at least one intersubband, wherein at least one transition of electrons in the at least one intersubband corresponds to detection of a photon.   The photodetector of claim 4, wherein the photons have an energy in the range of about several meV to several hundred meV. The photodetector of claim 1, wherein a plurality of waveguides and channels are disposed, and at least some of the waveguides are disposed between the channels to constitute an alternating arrangement of the waveguides and the channels .   The photodetector of claim 1, wherein the source and the drain are separated from each other. The photodetector of claim 1, wherein the at least one channel comprises at least one of a nanowire, a nanobelt, or a nanorod. The photodetector of claim 1, wherein the at least one channel comprises an array of at least one of nanowires, nanobelts, or nanorods. The photodetector of claim 1, wherein the at least one channel is selected from the group consisting of ZnO, Si, and InAs. The photodetector of claim 10, wherein each of the at least one channel is fabricated from the same material. The photodetector of claim 1, wherein each of the at least one channel is manufactured from a different type of material.   The photodetector of claim 1, wherein at least one of the at least two surface plasmon waveguides is made from a metallic material.   The photodetector according to claim 13, wherein the metal material is Ag.   The photodetector of claim 1, wherein the long wavelength radiation has a wavelength of at least 1 μm. The photodetector of claim 1, wherein the at least one channel has a width in a range from about 10 nm to about 500 nm. The photodetector of claim 1, wherein the at least one channel has a length in a range from about 0.5 μm to about 5 μm. The photodetector is capable of detecting a visible light spectrum, the photodetector is positioned in proximity to the at least one channel and the at least two surface plasmon waveguides, and the source and drain The photodetector of claim 1, further comprising a transparent gate disposed to extend substantially parallel to at least one of the two.   The photodetector of claim 18, wherein the transparent gate is disposed between the source and the drain. The photodetector of claim 18, wherein the transparent gate is disposed substantially perpendicular to the at least one channel . The photodetector of claim 18, wherein the channel is configured to have a valence band and a conduction band, and at least one transition of electrons from the valence band to the conduction band corresponds to detection of a photon. . The photodetector of claim 18, wherein the at least one channel is selected from the group consisting of a II-VI semiconductor compound and a III-V semiconductor compound. The photodetector of claim 18, wherein the at least one channel comprises Cd _x Zn _1-x S, and the value of x ranges from about 0.5 to about 1.0. The photodetector of claim 18, wherein the at least one channel comprises CdSe _x S _1-x and the value of x ranges from about 0 to about 0.4. The photodetector of claim 18, wherein the at least one channel comprises CdSe _x S _1-x and the value of x ranges from about 0.6 to about 1.0.   The photodetector of claim 18, wherein the transparent gate is made from a metallic material.   The photodetector of claim 18, wherein the visible light spectrum has a wavelength in the range of about 300 nm to several 800 nm. The photodetector of claim 1, wherein the transparent gate is configured such that an internal field of the at least one channel decreases when a reverse voltage is applied. A photodetector capable of detecting a visible light spectrum,
A first channel configured to perform first spectral detection;
A second channel configured to perform second spectral detection;
A third channel configured to perform third spectrum detection;
A source electrically coupled to a drain by the first channel , the second channel , and the third channel ;
At least two surface plasmon waveguides disposed between the source and the drain and juxtaposed with the at least one channel in a longitudinal direction of the at least one channel ;
A transparent gate positioned proximate to the at least one channel and the at least two surface plasmon waveguides and disposed to extend substantially parallel to at least one of the source and the drain When,
With
One of the at least two surface plasmon waveguides is disposed along a first side of the at least one channel , and the other of the at least two surface plasmon waveguides is on the first side. Arranged along a second side of the at least one channel facing each other;
The at least two surface plasmon waveguides confine photons around the at least one channel between the at least two surface plasmon waveguides;
Photo detector. 30. The photodetector of claim 29, wherein the color detected by the first channel is blue. 30. The photodetector of claim 29, wherein the color detected by the second channel is green. 30. The photodetector of claim 29, wherein the color detected by the third channel is red. A method for assembling a photodetector capable of detecting long wavelength radiation comprising:
Providing a source and a drain;
Electrically coupling the source and the drain with at least one channel ;
Disposing at least two surface plasmon waveguides between the source and the drain and juxtaposing the at least one channel in a longitudinal direction of the at least one channel ;
One of the at least two surface plasmon waveguides is disposed along a first side of the at least one channel , and the other of the at least two surface plasmon waveguides is on the first side. Arranged along a second side of the at least one channel facing each other;
The at least two surface plasmon waveguides confine photons around the at least one channel between the at least two surface plasmon waveguides;
Method. 34. The method of claim 33, wherein the at least one channel is created by an epitaxial growth technique.   34. The method of claim 33, comprising: creating a substrate; and creating an insulating layer on the substrate, wherein the source and the drain are disposed on the insulating layer. The photodetector can detect a visible light spectrum, and the method further comprises placing a transparent gate in a position proximate to the at least one channel and the at least two surface plasmon waveguides. 34. The method according to 33.

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