阅读说明：本技术 一种在应力为零的中性面上制备超柔性光探测器的方法 (Method for preparing ultra-flexible optical detector on neutral plane with zero stress ) 是由 王敏 陈红蕾 彭锐 叶传瑶 盛俊华 于 2019-08-26 设计创作，主要内容包括：本发明公开了一种在应力为零的中性面上制备超柔性光探测器的方法。材料弯曲时内部的中性力学平面上没有应变,采用该理论设计、测量制备的封装半导体薄膜光探测器在应变高达10%的情况下稳定工作,比外表面所能承受的应变大两个数量级。实际上,封装后的光探测器在弯曲过程中,只要衬底能够弯曲到目标弯曲曲率,器件都应该能稳定工作。同时,在弯曲1000小时或者弯曲10000次,都能表现出极稳定的光响应特性。这种结构的设计研究,有效解决了脆性光敏材料在柔性器件弯曲过程中断裂破损,导致器件无法工作的问题,将极大的推动柔性光探测器的应用。本发明提供的在应力为零的中性面上制备超柔性光探测器的方法工艺简单,成本低廉。(The invention discloses a method for preparing an ultra-flexible photodetector on a neutral plane with zero stress. The material has no strain on the internal neutral mechanical plane when being bent, and the packaged semiconductor film optical detector designed and measured by adopting the theory works stably under the condition that the strain is up to 10 percent and is two orders of magnitude larger than the strain which can be born by the outer surface. In fact, the packaged photodetector should be able to operate stably during the bending process, as long as the substrate is able to bend to the target bending curvature. Meanwhile, the optical response characteristics are very stable when the optical element is bent for 1000 hours or 10000 times. The design research of the structure effectively solves the problem that the device cannot work due to the fact that the brittle photosensitive material is broken and damaged in the bending process of the flexible device, and the application of the flexible light detector is greatly promoted. The method for preparing the ultra-flexible photodetector on the neutral plane with zero stress provided by the invention has the advantages of simple process and low cost.)

1. A method of fabricating an ultra-flexible photodetector in a neutral plane with zero stress, comprising the steps of:

(1) preparing a flexible substrate PET: cutting PET, ultrasonically cleaning the PET for 5 minutes by using acetone, ethanol and deionized water, drying the PET, placing the PET on a heating table for baking to enable the surface of the PET to be flat, placing the baked and flat PET in a plasma cleaning machine for high-grade cleaning for 15 minutes, and taking out the PET;

(2) evaporation of II-VI semiconductor materials: sticking the cleaned PET on an evaporation substrate of a cavity of an electron beam evaporation coating machine by using a high-temperature adhesive tape, and evaporating II-VI semiconductor materials on the PET at 60-100 ℃ by using an electron beam evaporation coating method to prepare a II-VI semiconductor film on the PET;

(3) constructing a II-VI semiconductor thin film photodetector: fixing the PET evaporated with the II-VI semiconductor film on an electrode mask plate, determining the area of an evaporated electrode, sticking and fixing the electrode mask plate on an evaporation substrate of a cavity of an electron beam evaporation coating machine by using a high-temperature adhesive tape, adjusting the parameters of the evaporated electrode, and evaporating 10 nm Cr/100 nm Au as an electrode to construct an II-VI semiconductor film optical detector;

(4) and (3) adhering PET on the upper layer of the device: cutting the PET with the same thickness as the PET in the step (1), spin-coating a layer of transparent UV glue on the surface of the PET by using a spin coater, adhering one side of the PET covered with the glue on the upper surface of the optical detector constructed in the step (3), irradiating the PET for three minutes by using an ultraviolet lamp with the wavelength of 365 nm, and waiting for 24 hours to air-dry and cure the glue.

2. A method of fabricating an ultra-flexible photodetector in a neutral plane with zero stress according to claim 1, wherein: the thickness of the PET in the step (1) and the thickness of the PET in the step (4) are both 100 μm, and the size of the PET is 3.5 multiplied by 3.5 cm.

3. A method of fabricating an ultra-flexible photodetector in a neutral plane with zero stress according to claim 1, wherein: and (2) baking the PET in the step (1) on a heating table at 90 ℃ for 5 minutes.

4. A method of fabricating an ultra-flexible photodetector in a neutral plane with zero stress according to claim 1, wherein: the thickness of the evaporated II-VI group semiconductor film in the step (2) is 200 nm, and the speed is 0.3-0.4A/s.

5. A method of fabricating an ultra-flexible photodetector in a neutral plane with zero stress according to claim 1, wherein: in the step (3), the rate of Cr vapor deposition is 0.2-0.3A/s, and the rate of Au vapor deposition is 0.4-0.5A/s.

6. A method of fabricating an ultra-flexible photodetector in a neutral plane with zero stress according to claim 1, wherein: and (4) the width of the channel of the electrode mask plate in the step (3) is 50 microns.

7. A method of fabricating an ultra-flexible photodetector in a neutral plane with zero stress according to claim 1, wherein: the rotating speed of the spin coating of the UV glue in the step (4) is 2000 rpm/10 seconds.

8. A method of fabricating an ultra-flexible photodetector in a neutral plane with zero stress according to claim 1, wherein: and (4) enabling the width of the upper layer PET to be smaller than that of the lower layer substrate PET, and exposing partial electrodes on two sides of the optical detection device.

Technical Field

The invention belongs to the technical field of semiconductor materials, and particularly relates to a method for preparing an ultra-flexible photodetector on a neutral plane with zero stress.

Background

In recent years, with the continuous development of wearable electronic device technology, the demand of mechanical flexible light detectors is rapidly increasing, and the flexible light detectors have become hot spots of research, especially in the medical and safety fields. Compared with the traditional optical detector on the rigid substrate, the device on the flexible substrate has flexibility in bending, compression and folding, so that the device has better research prospect in the society.

Currently, most of the research on flexible photodetectors focuses on the research of photosensitive materials. Lightweight, highly flexible organic materials have been widely used in flexible photodetectors. Another approach is to fabricate flexible devices based on inorganic materials including one-dimensional nanostructures and thin films. Here, we focus on the structure of the photodetector rather than the photosensitive material in the hope of realizing a highly flexible device based on various materials. By preparing the optical detector on the neutral plane with zero stress, the material has no strain on the internal neutral mechanical plane when being bent. In the bending process of the device with the structure, the flexible device is hardly affected by strain, and the device can stably work.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provides a method for preparing an ultra-flexible light detector on a neutral plane with zero stress.

The invention is realized by the following technical scheme:

a method of fabricating an ultra-flexible photodetector in a neutral plane with zero stress, comprising the steps of:

(1) preparing a flexible substrate PET: cutting PET which has no scratch, has the thickness of 100 mu m and the size of 3.5 multiplied by 3.5 cm, ultrasonically cleaning the PET for 5 minutes by using acetone, ethanol and deionized water, drying the PET, placing the PET on a heating table to bake the surface of the PET to be flat, placing the baked and flat PET on a plasma cleaning machine, cleaning the PET for 15 minutes, and taking out the PET.

(2) Evaporation of II-VI semiconductor materials: and sticking and fixing the prepared PET on an evaporation substrate of the cavity of the electron beam evaporation coating machine by using a high-temperature adhesive tape. And (3) evaporating and coating the II-VI semiconductor material on the PET at the low temperature of 60-100 ℃ by using an electron beam evaporation coating method, so as to prepare the II-VI semiconductor film on the PET.

(3) Constructing a II-VI semiconductor thin film photodetector: fixing PET of the II-VI semiconductor film on the evaporation plating on a special electrode mask plate, determining the area of an evaporation plating electrode, sticking and fixing the electrode mask plate on an evaporation substrate of a cavity of an electron beam evaporation film plating machine by using a high-temperature adhesive tape, adjusting the parameters of the plating electrode, and evaporating 10 nm Cr/100 nm Au as the electrode to construct the II-VI semiconductor film light detection device.

(4) And (3) adhering PET on the upper layer of the device: selecting prepared PET with the same thickness, spin-coating a layer of nearly transparent UV glue on the surface of the PET by using a spin coater, adhering one side of the PET covered with the glue on the upper surface of the constructed device, irradiating the PET for three minutes by using a 365 nm ultraviolet lamp, and waiting for 24 hours to air-dry and solidify the glue, thereby constructing the photodetector with the characteristics of a sandwich symmetrical structure.

The thickness of the PET is controlled at 100 μm.

The PET was baked on a heating table at 90 ℃ for 5 minutes.

The thickness of the semiconductor film evaporated in the step 2 is 200 nm, and the speed is 0.3-0.4A/s.

In the step 3, the rate of Cr vapor deposition is 0.2-0.3A/s, and the rate of Au vapor deposition is 0.4-0.5A/s.

And (4) the width of the channel of the electrode mask plate in the step (3) is 50 microns.

The rotating speed of the spin coating of the UV glue in the step 4 is 2000 rpm/10 seconds.

And (4) enabling the width of the upper layer PET to be smaller than that of the lower layer substrate PET, and exposing partial electrodes on two sides of the optical detection device.

The invention has the advantages that:

(1) the flexible substrate PET has the characteristics of transparency, insulation, light weight, high bending strength, low price and the like, and can not be broken, deformed and the like in the bending process.

(2) The substrate temperature is lower in the electron beam evaporation coating process, and the problems that the flexible substrate PET is sensitive to temperature and cannot resist high temperature are effectively solved.

(3) The electron beam evaporation coating has accurate film thickness and good film crystallinity.

(4) The neutral mechanical plane in the bent material has no strain, the theoretical design is adopted to construct the sandwich symmetrical structure film photodetector, the thicknesses and Young modulus of the PET layers on the upper layer and the lower layer are the same, and the device is manufactured on the neutral mechanical plane, so that the semiconductor film photodetector still stably works under the condition of strain and is two orders of magnitude larger than the strain which can be born by the conventional photodetector manufactured on the outer surface; the traditional optical detector cannot work under the curling condition, but the optical detector prepared on the neutral plane with zero stress can normally work under the curling condition, and the device can still stably work after being curled for thousands of times or hundreds of hours. The upper PET layer has a packaging function, so that the device is not easy to oxidize, fall off and damage, and the service life of the device is prolonged.

Detailed Description

The technical scheme of the invention is further explained by combining the specific examples as follows:

a method of fabricating an ultra-flexible photodetector in a neutral plane with zero stress, comprising the steps of:

(1) preparing a flexible substrate PET: cutting PET which has no scratch, has the thickness of 100 mu m and the size of 3.5 multiplied by 3.5 cm, ultrasonically cleaning the PET for 5 minutes by using acetone, ethanol and deionized water, drying the PET, placing the PET on a heating table to bake the surface of the PET to be flat, placing the baked and flat PET on a plasma cleaning machine, cleaning the PET for 15 minutes, and taking out the PET.

(2) Evaporation of II-VI semiconductor materials: and sticking and fixing the prepared PET on an evaporation substrate of the cavity of the electron beam evaporation coating machine by using a high-temperature adhesive tape. And (3) evaporating and coating the II-VI semiconductor material on the PET at the low temperature of 60-100 ℃ by using an electron beam evaporation coating method, so as to prepare the II-VI semiconductor film on the PET.

(3) Constructing a II-VI semiconductor thin film photodetector: fixing PET of the II-VI semiconductor film on the evaporation plating on a special electrode mask plate, determining the area of an evaporation plating electrode, sticking and fixing the electrode mask plate on an evaporation substrate of a cavity of an electron beam evaporation film plating machine by using a high-temperature adhesive tape, adjusting the parameters of the plating electrode, and evaporating 10 nm Cr/100 nm Au as the electrode to construct the II-VI semiconductor film light detection device.

(4) And (3) adhering PET on the upper layer of the device: selecting prepared PET with the same thickness, spin-coating a layer of nearly transparent UV glue on the surface of the PET by using a spin coater, adhering one side of the PET covered with the glue on the upper surface of the constructed device, irradiating the PET for three minutes by using a 365 nm ultraviolet lamp, and waiting for 24 hours to air-dry and solidify the glue, thereby constructing the photodetector with the characteristics of a sandwich symmetrical structure.

The thickness of the PET is controlled at 100 μm.

The PET was baked on a heating table at 90 ℃ for 5 minutes.

The thickness of the semiconductor film evaporated in the step 2 is 200 nm, and the speed is 0.3-0.4A/s.

In the step 3, the rate of Cr vapor deposition is 0.2-0.3A/s, and the rate of Au vapor deposition is 0.4-0.5A/s.

And (4) the width of the channel of the electrode mask plate in the step (3) is 50 microns.

The rotating speed of the spin coating of the UV glue in the step 4 is 2000 rpm/10 seconds.

And (4) enabling the width of the upper layer PET to be smaller than that of the lower layer substrate PET, and exposing partial electrodes on two sides of the optical detection device.