CN108872151A - It is a kind of based on T shape to and nano wire pair optical sensor - Google Patents

Abstract

The present invention relates to it is a kind of based on T shape to and nano wire pair optical sensor, including dielectric layer, metal Nano structure and substrate, metal Nano structure is dimeric structure, metal Nano structure includes the line style metal nano that is set in substrate to and positioned at T-type metal nano pair between line style metal nano pair, the distance between two respective longitudinal edges of T-type metal nanometer line of the distance between the both ends of the horizontal edge of each T-type metal nanometer line and corresponding line style metal nanometer line are equal, the equal length of the horizontal edge of the length and T-type metal nanometer line of the line style metal nanometer line, the width of the width of the longitudinal edge of T-type metal nanometer line and the width of horizontal edge and line style metal nanometer line is equal, the height of T-type metal nanometer line is equal with the height of line style metal nanometer line.The structure is simple, and preparation process requires difficulty to substantially reduce, and has sensing effect well, and the optical sensor of the structure can be easy to improve the sensitivity of sensor.

Description

An optical sensor based on T-shaped pair and nanowire pair

technical field

The invention relates to the field of sensors, in particular to an optical sensor based on a T-shaped pair and a nanowire pair.

Background technique

Sensors have higher and higher requirements in terms of miniaturization, automation, selectivity, stability, sensitivity, response time and service life, and the development and application of new sensing materials have been paid more and more attention. Using new materials to make new sensors has become one of the important directions of research, and the research on using nanowires as sensor sensitive materials is particularly attractive. This is mainly due to the huge specific surface area and high surface activity of one-dimensional nanomaterials, so they are particularly sensitive to the surrounding environment.

In 2011, Verellen N et al. proposed a metamaterial sensor based on the combination of X-type and nanowires in "Plasmon Line Shaping Using Nanocrosses for High Sensitivity Localized Surface Plasmon Resonance Sensing". The left side of the sensor is X-type, and the right side is Nanowires, their materials are all composed of gold, a three-layer structure consisting of medium, gold, and substrate from bottom to top, and the substrate is glass material. In this structure, the X-shaped structure has the characteristics of angle control, but the above-mentioned structure is difficult in the preparation process, and the preparation process requires high requirements. Moreover, due to the influence of this structure, the sensitivity of the sensor is not high, and sometimes it cannot meet the requirements of customers.

Contents of the invention

The object of the present invention is to provide an optical sensor based on T-shaped pair and nanowire pair with simple structure, easy processing and greatly improved sensitivity.

To achieve the above object, an optical sensor based on a T-shaped pair and a nanowire pair of the present invention adopts the following technical scheme: an optical sensor based on a T-shaped pair and a nanowire pair, including dielectric layers arranged in sequence from top to bottom , a metal nanostructure and a substrate, the metal nanostructure is a dimer structure, the metal nanostructure includes linear metal nano-pairs arranged on the upper surface of the substrate, and the linear metal nano-pairs include parallel and spaced linear metal nano-pairs extending longitudinally Metal nanowires, metal nanostructures also include T-shaped metal nano-pairs that are relatively arranged on the upper surface of the substrate between the linear metal nano-wires. type metal nanowires, the distance between the two ends of the transverse sides of each of the T-type metal nanowires and the corresponding linear metal nanowires is equal to the distance between the respective longitudinal sides of the two T-type metal nanowires, so The length of the linear metal nanowire is equal to the length of the transverse side of the T-shaped metal nanowire, the width of the longitudinal side of the T-shaped metal nanowire is equal to the width of the transverse side and the width of the linear metal nanowire, and the T-shaped metal nanowire The height of the wire is equal to the height of the linear metal nanowire.

The distance between the two ends of the transverse side and the corresponding linear metal nanowires is 10-60nm.

The distance between the two ends of the transverse side and the corresponding linear metal nanowires is 40nm.

The length of the linear metal nanowire is 80-150nm.

The length of the linear metal nanowire is 100nm.

The length of the longitudinal side of the T-shaped metal nanowire is 30nm-90nm.

The width of the linear metal nanowire is 10-50nm.

The width of the linear metal nanowire is 20nm.

The height of the T-shaped metal nanowire is 20-50nm.

The height of the T-shaped metal nanowire is 30nm.

Beneficial effects of the present invention: the metal nanostructure is a dimer structure, including a linear metal nano-pair and a T-shaped metal nano-pair located between the linear metal nano-pair, and the two lateral sides of each T-shaped metal nanowire The distance between the end and the corresponding linear metal nanowire is equal to the distance between the respective longitudinal sides of the two T-shaped metal nanowires, and the length of the linear metal nanowire is equal to that of the transverse side of the T-shaped metal nanowire. The lengths are equal, the width of the longitudinal side of the T-shaped metal nanowire is equal to the width of the transverse side and the width of the linear metal nanowire, and the height of the T-shaped metal nanowire is equal to the height of the linear metal nanowire. The structure is simple, the difficulty of the preparation process is greatly reduced, and the sensing effect is good, and the optical sensor with the structure can easily improve the sensitivity of the sensor. Light can be incident in any direction, and there is no difference in sensitivity due to the incident angle. This optical sensor is only sensitive to the refractive index of the object and has nothing to do with the intensity of light. No matter from which direction the light is incident, as long as it is irradiated on this structure, it can be detected and expressed as a change in wavelength.

Description of drawings

Fig. 1 is a kind of structural schematic diagram of an embodiment of the optical sensor based on T-shaped pair and nanowire pair of the present invention;

Fig. 2 is the top view of Fig. 1;

3 is a schematic diagram of the position structure of a T-type metal nano-pair and a linear metal nano-pair;

Fig. 4 is the extinction curve figure of the optical sensor obtained by theoretical calculation in the present embodiment;

Fig. 5 is the relation figure of incident wavelength and refractive index of the optical sensor obtained by theoretical calculation in the present embodiment;

Fig. 6 is the relationship figure of the figure of merit of the optical sensor that theoretical calculation obtains in the present embodiment, wherein P ₁ is the variation of short-wavelength wavelength with refractive index, P ₂ is the variation of long-wavelength wavelength with refractive index, their relation is FOM= m(nm RIU ^-1 )/FWHM (nm), m is the wavelength change when the refractive index changes in a unit, and FWHM is the half-wave width.

Detailed ways

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some, not all, embodiments of the present invention. All other embodiments obtained by persons of ordinary skill in the art based on the embodiments of the present invention belong to the protection scope of the present invention.

An embodiment of an optical sensor based on a T-shaped pair and a nanowire pair of the present invention: as shown in Figures 1-6, it includes a dielectric layer 1, a metal nanostructure and a substrate 2 arranged in sequence from top to bottom, and the substrate 2 It is a quartz plate, and the metal nanostructure is a dimer structure and embedded on the substrate 2 . The metal nanostructure includes linear metal nanopairs 3 with parallel and spaced linear metal nanowires 5 arranged on the upper surface of the substrate 2 , and the length of the linear metal nanowires 5 extends longitudinally. The metal nanostructure also includes T-shaped metal nano-pairs 4 oppositely arranged between the linear metal nanowires 5 on the upper surface of the substrate 2, and the T-shaped metal nano-pairs 4 include T-shaped metal nano-pairs with vertical sides 8 arranged at intervals and horizontal sides 7 arranged in parallel. type metal nanowires6. Wherein, the distance D between the two ends of the transverse side 7 of each T-shaped metal nanowire 6 and the corresponding linear metal nanowire 5 is equal to the distance D between the respective longitudinal sides 8 of the two T-shaped metal nanowires 6 , the length L of the linear metal nanowire 5 is equal to the length L of the lateral side 7 of the T-shaped metal nanowire 6, the width W of the longitudinal side 8 of the T-shaped metal nanowire 6 and the width W of the lateral side 7 and the linear metal nanowire The width W of the nanowires 5 is equal, and the height H of the T-shaped metal nanowires 6 is equal to the height H of the linear metal nanowires 5 . Light can be incident in any direction, and there is no difference in sensitivity due to the incident angle. This optical sensor is only sensitive to the refractive index of the object and has nothing to do with the intensity of light. No matter from which direction the light is incident, as long as it is irradiated on this structure, it can be detected and expressed as a change in wavelength. Both the linear metal nano-pair 3 and the T-shaped metal nano-pair 4 are made of metallic silver, and the dielectric layer 1 is air.

The distance D between the two ends of the transverse sides 7 of each T-shaped metal nanowire 6 and the corresponding linear metal nanowire 5 is 40 nm. The length of the linear metal nanowire 5 is 100 nm. The length S of the longitudinal side 8 of the T-shaped metal nanowire 6 is 40 nm. The width of the longitudinal side 8 of the T-shaped metal nanowire 6 is 20 nm. The height H of the T-shaped metal nanowire 6 is 30 nm.

The metal nanostructure is a dimer structure, the above-mentioned structure is simple, the difficulty of preparation process requirements is greatly reduced, and it has a good sensing effect, and the optical sensor with this structure can easily improve the sensitivity of the sensor. The mechanism of the optical sensor is to promote the plasmon interaction between each metal nanowire to generate different spectral responses by adjusting the parameters of the T-shaped metal nano-pair and the parameters of the linear metal nano-pair to achieve the sensing effect.

The preparation process of the above-mentioned optical sensor based on the T-shaped pair and the nanowire pair structure includes the following steps:

Step 1. Clean the substrate made of quartz: surface treatment is performed on the substrate first, and then pre-baked to remove water vapor and chemicals brought about by the surface treatment.

Step 2. Rotary gluing: use the spray gluing method, and the rotary gluing needs to go through several steps of glue dropping, low-speed rotation, and high-speed rotation.

Step 4. Exposure: Expose the photoresist under the action of a mask to prepare T-shaped pairs and nanowire pairs.

Step 5. Electron beam evaporation: use the electron beam evaporation system to evaporate the metal into the holes of the T-shaped pair and the nanowire pair.

Step 6. Development: corrode and develop the exposed photoresist with a developer.

Step 7. Cleaning: The corresponding structure can be obtained by washing off the photoresist. As shown in Figure 3.

The wave optics module of the finite element electromagnetic simulation software Comsol Multiphysics is used to simulate the sensing characteristics of the belt sensor. First, a structural model should be built in the software, and then periodic boundary conditions should be set. For boundary reflections, the influence can be eliminated by building a perfect matching layer, and finally the entire structure is simulated. The calculated extinction curve of the sensor is shown in Figure 4. The calculated relationship between the incident wavelength and the refractive index of the sensor is shown in Figure 5. The relationship diagram of the calculated quality factor of the sensor is shown in Fig. 6 .

In other embodiments of the present invention, the length of the linear metal nanowire is 80nm; the length of the linear metal nanowire is 150nm; the length of the longitudinal side of the T-shaped metal nanowire is 30nm; the length of the longitudinal side of the T-shaped metal nanowire The length of the T-type metal nanowire is 90nm; the width of the longitudinal side of the T-type metal nanowire is 10nm; the width of the longitudinal side of the T-type metal nanowire is 50nm; the height of the T-type metal nanowire is 20nm; the height of the T-type metal nanowire is 50nm ; The distance between the two ends of the horizontal side and the corresponding linear metal nanowire is 10nm; the distance between the two ends of the horizontal side and the corresponding linear metal nanowire is 60nm.

Claims (10)

1. it is a kind of based on T shape to and nano wire pair optical sensor, including dielectric layer, the metal from top to bottom set gradually Nanostructure and substrate, it is characterised in that：Metal Nano structure is dimeric structure, and metal Nano structure includes being set to substrate Upper surface on line style metal nano pair, line style metal nano to include parallel interval setting extend longitudinally line style gold Belong to nano wire, metal Nano structure further includes the T-type on the upper surface for being relatively arranged on substrate between line style metal nanometer line Metal nano pair, T-type metal nano is to including the setting of longitudinal edge relative spacing, horizontal edge T-type metal nanometer line disposed in parallel, each institute State the distance between the both ends of the horizontal edge of T-type metal nanometer line and corresponding line style metal nanometer line and two T-type metal nanos The distance between the respective longitudinal edge of line is equal, the length of the horizontal edge of the length and T-type metal nanometer line of the line style metal nanometer line Spend equal, the width of the width of the longitudinal edge of T-type metal nanometer line and the width of horizontal edge and line style metal nanometer line is equal, T-type The height of metal nanometer line is equal with the height of line style metal nanometer line.

2. it is according to claim 1 based on T shape to and nano wire pair optical sensor, it is characterised in that：The horizontal edge Both ends at a distance from corresponding line style metal nanometer line be 10-60nm.

3. it is according to claim 1 based on T shape to and nano wire pair optical sensor, it is characterised in that：The horizontal edge Both ends at a distance from corresponding line style metal nanometer line be 40nm.

4. it is according to claim 1 based on T shape to and nano wire pair optical sensor, it is characterised in that：The line style The length of metal nanometer line is 80-150nm.

5. it is according to claim 4 based on T shape to and nano wire pair optical sensor, it is characterised in that：The line style The length of metal nanometer line is 100nm.

6. it is according to claim 1 based on T shape to and nano wire pair optical sensor, it is characterised in that：The T-type gold The length for belonging to the longitudinal edge of nano wire is 30nm-90nm.

7. it is according to claim 1 based on T shape to and nano wire pair optical sensor, it is characterised in that：The line style The width of metal nanometer line is 10-50nm.

8. it is according to claim 7 based on T shape to and nano wire pair optical sensor, it is characterised in that：The line style The width of metal nanometer line is 20nm.

9. it is according to claim 1 based on T shape to and nano wire pair optical sensor, it is characterised in that：The T-type gold The height for belonging to nano wire is 20-50nm.

10. it is according to claim 9 based on T shape to and nano wire pair optical sensor, it is characterised in that：The T-type The height of metal nanometer line is 30nm.