CN113073391A

CN113073391A - Preparation method of organic semiconductor single crystal array

Info

Publication number: CN113073391A
Application number: CN202110325258.9A
Authority: CN
Inventors: 汪宏; 方震宇
Original assignee: Sun Yat Sen University Shenzhen Campus
Current assignee: Sun Yat Sen University Shenzhen Campus
Priority date: 2021-03-26
Filing date: 2021-03-26
Publication date: 2021-07-06
Anticipated expiration: 2041-03-26
Also published as: CN113073391B

Abstract

The invention provides a preparation method of an organic semiconductor single crystal array, which comprises the following steps: s1: constructing a patterned nucleation template on the surface of the substrate to obtain a patterned sample, and uniformly and dispersedly coating organic semiconductor crystal particles on a clean substrate; s2: placing the patterned sample above the substrate, wherein one side of the patterned sample, which is constructed with the nucleation template, is opposite to one side of the substrate, which is coated with the organic semiconductor crystal particles, and the side of the substrate and the side are separated by a plurality of distances; s3: and heating the substrate for a certain time, thereby preparing the organic semiconductor single crystal array on the patterned sample. The invention provides a preparation method of an organic semiconductor single crystal array, which solves the problem that the resolution ratio of the single crystal array prepared by the solution-assisted method is low at present.

Description

Preparation method of organic semiconductor single crystal array

Technical Field

The invention relates to the technical field of single crystal array preparation, in particular to a preparation method of an organic semiconductor single crystal array.

Background

Organic semiconductors are receiving increasing attention for their potential applications in the manufacture of flexible circuits and biocompatible devices. Recently, Organic Light Emitting Diodes (OLEDs) have been widely used in display devices for televisions, mobile phones, in-vehicle display screens, and smartwatches. In addition, organic semiconductors are also potentially useful in organic electronics and optoelectronics, such as Organic Field Effect Transistors (OFETs), photovoltaic devices, organic sensors, organic detectors, and organic semiconductor lasers, to name a few.

Compared with other candidate materials such as polymers and oligomers, the organic small molecules have the advantages of high carrier mobility, high on-off ratio and the like. These small molecules can be arranged on the substrate in a highly ordered orientation under vacuum conditions to avoid the production of other impurities.

In organic electronics, OFETs are one of the most basic components, which form the basis and core of organic circuits. In the fabrication of organic circuits, it is desirable to electrically isolate micro/nano-sized organic single crystal devices within the circuit from each other to avoid cross-talk between adjacent devices. For inorganic semiconductors, the fabrication of circuits is largely by deposition of single crystal thin films on substrates, which are then processed into discrete devices by various patterning techniques, such as photolithography. However, since the organic semiconductor is degraded by exposure to an organic solvent or ultraviolet light during photolithography, it is difficult to apply the photolithography technique to patterning of the organic semiconductor.

To overcome this difficulty, various other methods of preparing single crystal arrays have been attempted. For example, Bao et al ((j.am. chem. soc.2012,134,2760) use a polymer mold as a template to control the flow of a solution along a contact line, and during evaporation of the solvent, organic single crystals grow at the contact of the solution and a substrate as the solvent evaporates.

However, the resolution of the single crystal array produced by the solution-assisted method is relatively low, the defect density is also relatively high, and the production efficiency is not high enough.

Disclosure of Invention

The invention provides a preparation method of an organic semiconductor single crystal array, aiming at overcoming the technical defect that the resolution ratio of the single crystal array prepared by the solution-assisted method is low at present.

In order to solve the technical problems, the technical scheme of the invention is as follows:

a method for preparing an organic semiconductor single crystal array comprises the following steps:

s1: constructing a patterned nucleation template on the surface of the substrate to obtain a patterned sample,

uniformly and dispersedly coating organic semiconductor crystal particles on a clean substrate;

s2: placing the patterned sample above the substrate, wherein one side of the patterned sample, which is constructed with the nucleation template, is opposite to one side of the substrate, which is coated with the organic semiconductor crystal particles, and the side of the substrate and the side are separated by a plurality of distances;

s3: and heating the substrate for a certain time, thereby preparing the organic semiconductor single crystal array on the patterned sample.

Preferably, in step S1, the patterned sample is obtained by:

s1.1: successively putting the substrate into acetone, ethanol and water, and ultrasonically cleaning for at least 5 minutes;

s1.2: drying the cleaned substrate;

s1.3: photoetching the substrate according to the pattern of the nucleation template to be constructed;

s1.4: sequentially evaporating a first adhesion layer and a second adhesion layer on the substrate subjected to photoetching by a vacuum evaporation method;

s1.5: stripping the residual photoresist from the substrate subjected to vacuum evaporation by using a stripping liquid to complete the construction of a patterned nucleation template on the surface of the substrate to obtain a patterned sample;

wherein the patterned nucleation template is a geometric figure or an electrode pair;

and after obtaining the patterned sample, sequentially putting the patterned sample into acetone, ethanol and water, respectively carrying out ultrasonic cleaning for at least 5 minutes, and then drying the cleaned patterned sample.

Preferably, the first and second liquid crystal materials are,

the first adhesion layer is chromium, titanium, nickel or aluminum,

the thickness of the first adhesion layer is 1-20 nm;

the second adhesion layer is gold and is formed by a first adhesion layer,

the thickness of the second adhesion layer is 3-100 nm.

Preferably, the size of the patterned nucleation template is 10nm to 10 μm.

Preferably, the size of the patterned nucleation template is 1 μm to 4 μm.

Preferably, the substrate is a rigid substrate or a flexible substrate;

wherein the content of the first and second substances,

the rigid substrate is a silicon wafer, sapphire or glass;

the flexible substrate is polyethylene terephthalate (PET) or polyethylene naphthalate (PEN).

Preferably, the substrate is a metal plate, a silicon wafer or a sapphire wafer.

Preferably, the substrate is a silicon wafer.

Preferably, in step S2, the substrate and the patterned sample are spaced apart by several distances by placing glass strip spacers on both sides of the substrate and then placing the patterned sample upside down on the two glass strip spacers.

Preferably, the distance between the patterned sample and the substrate is 100-300 μm.

Preferably, in step S3, the substrate is heated by a hot stage at a temperature of 100 to 400 ℃ for 10 to 300 seconds.

Compared with the prior art, the technical scheme of the invention has the beneficial effects that:

the invention provides a preparation method of an organic semiconductor single crystal array, which comprises the steps of constructing a patterned nucleation template on the surface of a substrate, and taking the nucleation template as a nucleation center to induce the subsequent nucleation and growth of organic semiconductor molecules; and the silicon chip coated with the organic semiconductor crystal particles is heated, so that the organic semiconductor single crystal array can be prepared on the surface of the patterned sample, the organic semiconductor single crystal array with a large area can be prepared in a short time by only carrying out ultra-short distance thermal evaporation in the air without the help of organic solvents for dissolution and using vacuum equipment, and the organic semiconductor single crystal array prepared by the method has the advantages of high density, low defect, uniform grain size and the like, and can be potentially applied to the preparation of organic circuits with high integration level and high performance.

Drawings

FIG. 1 is a flow chart of the steps for implementing the technical solution of the present invention;

FIG. 2 is a schematic diagram of an embodiment of the present invention for preparing a single crystal array of organic semiconductors on a patterned substrate;

FIG. 3 is an optical microscopic representation of the present invention showing the formation of a single crystal array of the organic semiconductor perylene on a patterned silicon wafer;

FIG. 4 is an Atomic Force Microscopy (AFM) schematic of a single crystal surface on a single crystal array of the organic semiconductor perylene obtained on a patterned silicon wafer in accordance with the present invention;

fig. 5 is an optical microscopic representation of the present invention resulting in a single crystal array of the organic semiconductor TCNQ on a patterned silicon wafer.

Detailed Description

The drawings are for illustrative purposes only and are not to be construed as limiting the patent;

for the purpose of better illustrating the embodiments, certain features of the drawings may be omitted, enlarged or reduced, and do not represent the size of an actual product;

it will be understood by those skilled in the art that certain well-known structures in the drawings and descriptions thereof may be omitted.

The technical solution of the present invention is further described below with reference to the accompanying drawings and examples.

Example 1

As shown in fig. 1-2, a method for manufacturing an organic semiconductor single crystal array includes the steps of:

s1: the patterned nucleation template is constructed on the surface of the substrate by patterning preparation methods such as photoetching, electron beam exposure or transfer printing, etc., so as to obtain a patterned sample,

the method comprises the following steps of uniformly and dispersedly coating organic semiconductor crystal particles on a clean substrate in a mode of coating by using a scraper, preparing a solution and spraying or vacuum evaporation;

Example 2

More specifically, in step S1, a patterned sample is obtained by:

in practical implementation, the substrate is preferably placed into acetone, ethanol and water to be ultrasonically cleaned for 15 minutes respectively, so as to ensure that the substrate is clean and pollution-free;

s1.2: drying the cleaned substrate;

in actual implementation, the cleaned substrate is blown dry by nitrogen, and the nitrogen is low in cost and clean enough;

in practical implementation, the photoetching process comprises spin-coating a film by using a photoresist, photoetching, developing, then evaporating a first adhesion layer and a second adhesion layer, and finally washing off the residual photoresist to obtain an array pattern, namely the pattern of the nucleation template to be constructed; in the photolithography process, the pitch between the single crystals in the finally prepared single crystal array is controlled to be between 100nm and 15 μm, preferably between 5 μm and 10 μm by controlling the pitch of the formed array pattern.

after obtaining the patterned sample, the method also comprises the steps of putting the patterned sample into acetone, ethanol and water, carrying out ultrasonic cleaning for at least 5 minutes respectively, and then drying the cleaned patterned sample;

in practical implementation, the patterned sample is preferably placed into acetone, ethanol and water to be ultrasonically cleaned for 15 minutes respectively so as to ensure that the patterned sample is cleaned, and then the cleaned patterned sample is dried by nitrogen.

More specifically, in step S2, the substrate and the patterned sample are spaced apart by a certain distance by placing glass strip spacers on both sides of the substrate and then placing the patterned sample upside down on the two glass strip spacers.

The first adhesion layer is chromium, titanium, nickel or aluminum,

the thickness of the first adhesion layer is 1-20 nm;

in practical implementation, the thickness of the first adhesion layer is adjusted according to the requirements of different occasions, and the minimum thickness is 1nm and the maximum thickness is 20 nm;

the second adhesion layer is gold and is formed by a first adhesion layer,

the thickness of the second adhesion layer is 3-100 nm;

in practical application, the thickness of the second adhesive layer should be adjusted according to the requirements of different occasions, and the minimum thickness is 3nm and the maximum thickness is 100 nm.

More specifically, the size of the patterned nucleation template is 10nm to 10 μm.

In particular implementations, the patterned nucleation template may be circular or rectangular, where the dimensions of the circle refer to the diameter and the dimensions of the rectangle refer to the length and width; the size of the patterned nucleation template is 10nm at the minimum and 10 μm at the maximum.

More specifically, the patterned nucleation template has a size of 1 μm to 4 μm.

More specifically, the substrate is a rigid substrate or a flexible substrate;

wherein the content of the first and second substances,

the rigid substrate is a silicon wafer, sapphire or glass;

More specifically, the substrate is a metal plate, a silicon wafer or a sapphire wafer.

More specifically, the substrate is a silicon wafer.

More specifically, the present invention is to provide a novel,

more specifically, the distance between the patterned sample and the substrate is 100-300 μm.

In practice, the patterned sample is separated from the substrate by placing a glass sliver spacer between them, the distance between them being equal to the height of the glass sliver spacer; the glass slender gasket with different heights is adopted according to the requirements of different occasions, and the height of the glass slender gasket is 100 micrometers at the minimum and 300 micrometers at the maximum.

More specifically, in step S3, the substrate is heated by a hot stage at a temperature of 100 to 400 ℃ for 10 to 300 seconds.

In the specific implementation process, different heating temperatures and heating times are selected according to the requirements of different occasions to perform ultra-short-distance thermal evaporation on the organic semiconductor crystal particles, so that the large-area organic single crystal array is prepared and obtained in a short time.

Example 3

In this embodiment, a single crystal array of an organic semiconductor perylene is prepared on a patterned substrate, wherein the substrate and the base plate are both silicon wafers, specifically:

(1) cleaning a silicon wafer: ultrasonically cleaning a silicon wafer serving as a substrate in acetone, ethanol and water for 15 minutes respectively, and then drying the silicon wafer by using nitrogen;

(2) photoetching the cleaned silicon wafer: selecting a JASP-41 positive photoresist as a photoresist, carrying out spin coating at the rotating speed of 4500rpm for 25s, heating at 110 ℃ for 90 s after spin coating, carrying out ultraviolet exposure, soaking in JAZX-238 developing solution for 60 s, washing with deionized water for 30 s, and finally heating at 120 ℃ for 120 s;

(3) carrying out vacuum evaporation on the silicon wafer after photoetching: putting the photoetched silicon wafer into a vacuum environment, and plating 3nm chromium and 3nm gold by thermal evaporation;

(4) and (3) stripping the residual photoresist: stripping the residual photoresist of the silicon wafer subjected to vacuum evaporation by using a stripping liquid, and only leaving the pattern of an exposure area on the silicon wafer to complete patterning of the silicon wafer;

(5) cleaning the patterned silicon wafer, namely ultrasonically cleaning the patterned silicon wafer in acetone, ethanol and water for 15 minutes respectively, and then drying the patterned silicon wafer by using nitrogen;

(6) uniformly and dispersedly coating perylene on a silicon chip serving as a substrate;

(7) placing glass strip gaskets with the height of 150 mu m on two sides of the silicon wafer coated with the perylene, then placing the patterned silicon wafer on the two glass strip gaskets upside down, and then heating the silicon wafer coated with the organic semiconductor perylene at the heating temperature of 180 ℃ for 30 seconds to complete the preparation of the single crystal array of the organic semiconductor perylene, wherein the optical microscope and AFM photos of the array are shown in figures 3 and 4.

The optical microscope photo shows that the preparation method of the organic semiconductor single crystal array realizes a high-resolution organic semiconductor array, and the organic molecules in the array are subjected to AFM scanning, so that the organic molecules have obvious step flow patterns, and the organic molecules prepared by the method are organic single crystal molecules.

Example 4

In this embodiment, a single crystal array of an organic semiconductor TCNQ is prepared on a patterned substrate, where the substrate and a base plate both use silicon wafers, specifically:

(2) carrying out electron beam exposure and vacuum evaporation on the cleaned silicon wafer to complete patterning of the silicon wafer;

(3) cleaning the patterned silicon wafer: ultrasonically cleaning the patterned silicon wafer in acetone, ethanol and water for 15 minutes respectively, and then drying the patterned silicon wafer by using nitrogen;

(4) uniformly and dispersedly coating TCNQ on a silicon chip serving as a substrate;

(5) placing glass slender gaskets with the height of 150 mu m on two sides of the silicon wafer coated with the TCNQ, then inversely placing the patterned silicon wafer on the two glass slender gaskets, and then heating the silicon wafer coated with the organic semiconductor TCNQ at the temperature of 130 ℃ for 30 seconds; a single crystal array of the organic semiconductor perylene is prepared and the optical microscope of the array is shown in fig. 5.

As can be seen from the optical microscope photograph, the preparation method of the organic semiconductor single crystal array realizes the high-resolution organic semiconductor array.

It should be understood that the above-described embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A method for preparing an organic semiconductor single crystal array is characterized by comprising the following steps:

2. The method for producing an organic semiconductor single crystal array according to claim 1, wherein in step S1, the patterned sample is obtained by:

s1.2: drying the cleaned substrate;

3. The method for producing a single-crystal array of organic semiconductors according to claim 2,

the first adhesion layer is chromium, titanium, nickel or aluminum,

the thickness of the first adhesion layer is 1-20 nm;

the second adhesion layer is gold and is formed by a first adhesion layer,

the thickness of the second adhesion layer is 3-100 nm.

4. The method for preparing a single crystal array of organic semiconductors according to claim 1 or 2, wherein the size of the patterned nucleation template is 10nm to 10 μm.

5. The method for producing an organic semiconductor single crystal array according to claim 1, wherein the substrate is a rigid substrate or a flexible substrate;

wherein the content of the first and second substances,

the rigid substrate is a silicon wafer, sapphire or glass;

the flexible substrate is polyethylene terephthalate or polyethylene naphthalate.

6. The method for preparing a single-crystal array of organic semiconductors according to claim 1, wherein the substrate is a metal plate, a silicon wafer, or a sapphire wafer.

7. The method for producing an organic semiconductor single-crystal array according to claim 6, wherein the substrate is a silicon wafer.

8. The method of claim 1, wherein the substrate and the patterned sample are spaced apart by a plurality of distances by placing glass strip spacers on both sides of the substrate and then placing the patterned sample upside down on the two glass strip spacers in step S2.

9. The method for preparing a single crystal array of organic semiconductors according to claim 1, wherein the distance between the patterned sample and the substrate is 100 to 300 μm.

10. The method of claim 1, wherein the substrate is heated by a hot stage at 100-400 ℃ for 10-300S in step S3.