CN109989112B

CN109989112B - Method for preparing heterostructure material by utilizing light response behavior and application thereof

Info

Publication number: CN109989112B
Application number: CN201910288571.2A
Authority: CN
Inventors: 李治洲; 廖良生; 王雪东
Original assignee: Suzhou University
Current assignee: Suzhou University
Priority date: 2019-04-11
Filing date: 2019-04-11
Publication date: 2020-06-05
Anticipated expiration: 2039-04-11
Also published as: CN109989112A

Abstract

The invention discloses a method for preparing a heterostructure material by utilizing a light response behavior, which comprises the following steps: the material is partially exposed to light radiation, so that the radiated part and the radiated light perform photoresponse actions, and the property difference is generated between the non-radiated part and the radiated part, thereby forming the heterostructure material. The invention also discloses application of the method in preparing an optical waveguide device with an organic single crystal heterostructure. The method for preparing the heterostructure material by utilizing the light response behavior can directly modify the material without adding other materials, thereby preparing the heterostructure crystal.

Description

Method for preparing heterostructure material by utilizing light response behavior and application thereof

Technical Field

The invention relates to the technical field of heterostructure materials, in particular to a method for preparing a heterostructure material by utilizing a light response behavior and application thereof.

Background

With the development of science and technology, modern technology gradually enters a stage of needing to perform precise property regulation and control and preparation on micro-nano-scale devices. For example, the development of chips has gradually entered the 7nm process age, and a new generation of photonic chips is rising, requiring preparation of a large number of complex structures with micro-nano scale. In addition, in the fields of light emitting diodes, lasers, transistors and the like, higher requirements are also put forward on the structure control of the micro-nano scale. Of which heterostructures, are one of particular importance.

Heterostructure refers to a structure that integrates multiple material structures into a single body, which can integrate multiple properties together to create a particular performance due to the synergistic and versatility of the different structures. According to the material division, the heterostructure can be simply divided into an organic heterostructure, an inorganic heterostructure and an organic-inorganic hybrid heterostructure. In semiconductor electronics, heterojunctions can be divided into homotype heterojunctions (P-P junctions or N-N junctions) and heterotype heterojunctions (P-N or P-N) according to the difference in conductivity type between the two materials, and multilayer heterojunctions are called heterostructures. According to the composite interfaces with different structures, the heterojunction can be divided into a mutation heterojunction and a graded heterojunction. With the development of technology, the heterostructure has wide and important applications in various fields, such as typical organic heterojunction solar cells, organic light emitting diodes, laser diodes, heterostructure bipolar transistors, high-speed electron mobility transistors, and the like.

The crystalline material has more intrinsic and more stable properties compared with the amorphous material due to the periodic structural arrangement, and the optical properties, the morphology and other characteristics of the crystalline material can be adjusted by means of doping, chemical reaction and the like. The heterostructure crystal can integrate the characteristics of various materials in the preparation of photonic devices, thereby bringing more excellent performance.

Some common methods for heterojunction preparation at present are molecular beam epitaxy, metal oxide-chemical vapor deposition (MO-CVD), liquid phase epitaxy, chemical bath deposition, physical vapor deposition, assisted chemistry, and Sol-Gel (Sol-Gel). As in the fabrication of organic heterojunction solar cells, the technique of physical vapor deposition is often used, in which a powder of material is placed in an evaporation chamber, the material is heated until sublimation and then deposited on a substrate; after the deposition of the different materials, respectively, heterostructures can be obtained. For another example, molecular beam epitaxy is a method of preparing a single crystal film by ejecting each component constituting a crystal and doped atoms (molecules) from an ejection furnace onto a substrate at a certain thermal movement rate and in a certain ratio under an ultra-high vacuum condition to perform crystal epitaxial growth; by multiple epitaxial growth, different heterostructures can be obtained.

The main defects of the prior art are as follows: it is difficult to prepare the heterostructure crystal with accurate and controllable height for the crystalline material with the micro-nano scale. As is common with physical vapor deposition, it produces thin film samples often on a macro scale (>1 cm); and it is difficult to fabricate complex and precise heterostructures. In addition, in the actual heterostructure manufacturing process, the structure of the material is often patterned in combination with the photolithography process, so that a more accurate structure is manufactured. The photolithography method is highly dependent on the photoresist, and the whole process shows low compatibility with non-silicon-based materials. Other methods, such as etching, molecular beam epitaxy, etc., have the same difficulties. However, in the preparation process of many devices, a single material with a micro-nano scale is often used as a device, and how to prepare a heterocrystal with high spatial accuracy, compact structure and different properties is still a problem. In summary, the prior art has the following disadvantages:

(1) the preparation of a heterostructure crystal with tight connection and regular appearance is difficult;

(2) the method is difficult to directly modify the crystal with the micro-nano scale without adding other materials to prepare a heterostructure crystal;

(3) the high spatial position resolution of the crystal heterostructure transformation part is difficult to realize;

(4) the existing method is difficult to realize the compatibility of various materials such as organic materials, inorganic materials, organic-inorganic hybrid materials and the like.

Disclosure of Invention

The technical problem to be solved by the invention is to provide a method for preparing a heterostructure material by utilizing a light response behavior, and the method can directly modify the material without adding other materials so as to prepare a heterostructure crystal.

In order to solve the above technical problems, the present invention provides a method for preparing a heterostructure material using a photo-response behavior, comprising:

the material is partially exposed to light radiation, so that the radiated part and the radiated light perform photoresponse actions, and the property difference is generated between the non-radiated part and the radiated part, thereby forming the heterostructure material.

Further, the photo-responsive behavior includes structural transformations, changes in optical properties (e.g., light absorption, light emission, etc.), changes in morphology, changes in mechanical properties (e.g., elasticity, tensile properties, etc.), and changes in chemical properties (e.g., catalytic properties, etc.).

Further, said partially exposing the material to light radiation is in particular:

adding mask plate or using point light source to irradiate material on the light path.

In the invention, the method can be carried out on a macro scale (>1000 μm), a meso scale (1-1000 μm) and a micro scale (<1 μm); preferably, the material is a micro-nano material with the size smaller than 1000 μm.

In the invention, the material comprises organic material, inorganic material and organic-inorganic hybrid material; preferably, the material is a crystalline material.

The interface connection between the photoresponsive part and the nonresponsive part in the heterostructure material obtained by the invention comprises but is not limited to lattice matching, chemical bonds (including covalent bonds, metal bonds and ionic bonds), intermolecular forces (such as hydrogen bonds, halogen bonds, pi-pi stacking and the like).

The invention also aims to provide application of the method in preparing an optical waveguide device with an organic single crystal heterostructure.

In a preferred embodiment of the present invention, the application specifically comprises:

placing the o-BCB rodlike crystal under a microscope, using a xenon lamp as an illumination light source, and irradiating the o-BCB rodlike crystal by focusing of a microscope lens after xenon lamp light passes through a CCD and a grating in sequence; inserting a mask plate in the light path to enable the o-BCB crystal to be partially shielded; and after the irradiation is carried out for 20-40 minutes, converting the irradiated part into a crystal emitting blue light, thereby obtaining the o-BCB heterostructure crystal optical waveguide device.

Further, the o-BCB heterostructure crystal optical waveguide device is a crystal having a multi-block heterostructure.

The invention has the beneficial effects that:

1. the method can directly modify the material without adding other materials, including structure transformation, optical property change and the like, thereby preparing the heterostructure crystal.

2. The invention can be carried out on materials with the size of a macro scale and the size of a nanometer scale by a light radiation method.

3. The invention can be accurately controlled to be carried out on a specific area through a microscope by a light radiation method, thereby realizing the highly accurate property transformation of the material at the spatial position;

4. the interface connection of the heterostructure material prepared by the invention can be connected through lattice matching, chemical bonds and the like, and the connection is very tight and stable.

5. The optical radiation method used by the invention can be compatible with the existing photoetching process, thereby being capable of operating on various materials such as organic materials, inorganic materials, organic-inorganic hybrid materials and the like, and having wide applicability.

Drawings

FIG. 1 is a structural diagram of the o-BCB molecule in example 1;

FIG. 2 is a schematic optical path diagram of a microspectroscopic system used in example 1;

FIG. 3 is a photomicrograph of o-BCB rod crystals of example 1;

FIG. 4 is a schematic view of a reticle shape used in example 1;

FIG. 5 is a photograph of example 1 in which half of the o-BCB crystal was masked by the reticle;

FIG. 6 is a photograph of the o-BCB crystal heterostructure prepared in example 1;

FIG. 7 is a schematic reticle shape used in example 2;

FIG. 8 is a photograph of a crystal masked by a reticle discontinuity in example 2;

FIG. 9 is a photomicrograph of a triblock heterostructure crystal prepared in example 2 after being excited by ultraviolet light;

FIG. 10 is a photomicrograph of a pentablock heterostructure crystal prepared in example 2 excited by ultraviolet light;

FIG. 11 is a photomicrograph of a heptablock heterostructure crystal prepared in example 2 excited by ultraviolet light;

fig. 12 is an optical waveguide device based on a heterostructure crystal in example 3.

Detailed Description

The present invention is further described below in conjunction with the following figures and specific examples so that those skilled in the art may better understand the present invention and practice it, but the examples are not intended to limit the present invention.

In the following examples, the o-BCB crystal used is a molecule that undergoes a photochromic reaction under xenon lamp illumination, and the molecular structure thereof is shown in FIG. 1. Under the irradiation of a xenon lamp, double bond cis-trans isomerization can occur, so that the property of the aggregation state is changed.

The o-BCB micro-nano crystal is prepared by a solution precipitation method, and the method comprises the following specific steps: dissolving o-BCB powder in dichloromethane to prepare a solution with the concentration of 5mmol/L and 200 microliters, then quickly adding 2mL of ethanol into the solution, and vigorously stirring the solution to separate out a large amount of crystals in the solution, so that a crystal suspension is formed, sucking the crystal suspension by using a suction pipe, dripping the crystal suspension on a quartz plate, and volatilizing and drying the crystal suspension to obtain a large amount of rod-shaped crystals.

In the following examples, all the Fluorescence Microscope systems used in the following examples are german Leica Fluorescence Microscope (Fluorescence Optical Microscope) DM4000M Microscope, and the used microspectroscopic system is a self-built microspectroscopic system, and the basic Optical path is shown in fig. 2.

Example 1

The o-BCB rod-shaped crystal (the length is 5-200 microns) is placed under an optical microscope (as shown in figure 3), a xenon lamp is used as an illumination light source, and lamp light passes through an upper light path and is focused by a microscope lens to irradiate on the crystal. A mask plate (shaped as shown in FIG. 4) is inserted into the optical path so that half of the o-BCB rod crystal is blocked. As shown in fig. 5, the dark portion is the portion that is shielded by the reticle, and the bright portion is the portion that is illuminated. After about 30 minutes, the irradiated fraction was converted into blue-emitting crystals, resulting in two-block heterostructured crystals of o-BCB (fig. 6).

Example 2

The procedure was as in example 1. The mask shape in the first embodiment is changed to a hollow shape, and as shown in fig. 7, crystals with longer lengths are selected to be discontinuously shielded by the mask (as shown in fig. 8), so that a heterostructure crystal with three blocks (fig. 9), five blocks (fig. 10), seven blocks (fig. 11), or even any blocks can be obtained.

Example 3

As shown in fig. 12, using the microspectroscopic system of fig. 2, one end of the two-block heterostructure is excited by a laser with a wavelength of 375, and output light can be obtained at the other end, and the output light is a mixed spectrum of blue light and green light of two structure spectra, thereby constructing a simple optical waveguide device based on the heterostructure crystal.

The above-mentioned embodiments are merely preferred embodiments for fully illustrating the present invention, and the scope of the present invention is not limited thereto. The equivalent substitution or change made by the technical personnel in the technical field on the basis of the invention is all within the protection scope of the invention. The protection scope of the invention is subject to the claims.

Claims

1. A method of fabricating a heterostructure material using photoresponsive behavior, comprising:

a xenon lamp is used as a light source, the light is partially irradiated on an o-BCB crystal after being focused by a microscope, the irradiation time is 20-40 minutes, the irradiated part and the irradiated light are subjected to light response behaviors, and therefore the non-irradiated part and the irradiated part generate property difference to form a heterostructure material.

2. The method of claim 1, wherein the photoresponsive behavior comprises a structural transformation and a change in an optical property.

3. The method for preparing a heterostructure material using photo-responsive behavior of claim 1, wherein the partially irradiating on the o-BCB crystal is specifically:

adding a mask plate in the light path or using a point light source to irradiate the o-BCB crystal.

4. The method for preparing a heterostructure material using photo-responsive behavior of claim 1, wherein the o-BCB crystal has a length of 5 to 200 μm.

5. Use of the method according to any one of claims 1 to 4 for the preparation of an optical waveguide device of an organic single crystal heterostructure.

6. The application according to claim 5, wherein the application is in particular:

placing the o-BCB rodlike crystal under a microscope, using a xenon lamp as an illumination light source, and irradiating the o-BCB rodlike crystal by focusing of a microscope lens after xenon lamp light passes through a CCD and a grating in sequence; and inserting a mask plate in the light path to partially shield the o-BCB crystal, and converting the irradiated part into a crystal emitting blue light, thereby obtaining the o-BCB heterostructure crystal optical waveguide device.

7. The use of claim 6, wherein the o-BCB heterostructure crystal optical waveguide device is a crystal with a multi-block heterostructure.