阅读说明：本技术 一种基于石墨烯墙/硅复合异质结的光电探测器及其制备方法 (Photoelectric detector based on graphene wall/silicon composite heterojunction and preparation method thereof ) 是由 王怀昌 付永启 杨俊� 于 2019-10-23 设计创作，主要内容包括：本发明公开了一种基于石墨烯墙/硅复合异质结的光电探测器及其制备方法。在本发明中中,为了研究石墨烯墙/硅复合的光电探测器,用n掺杂的硅衬底制造了石墨烯墙/硅复合异质结的光电探测器,并采用两层光刻胶进行光刻,然后进行反应离子刻蚀(RIE)工艺,以实现基于石墨烯墙/硅复合的高质量石墨烯墙沟道和光电导探测器。石墨烯墙和硅形成肖特基势垒,将光生电子-空穴对分开。空穴进入石墨烯墙道,利用光致栅控效应,可以实现高的光响应增益。(The invention discloses a photoelectric detector based on a graphene wall/silicon composite heterojunction and a preparation method thereof. In the invention, in order to research a graphene wall/silicon composite photoelectric detector, the photoelectric detector of the graphene wall/silicon composite heterojunction is manufactured by using an n-doped silicon substrate, two layers of photoresist are adopted for photoetching, and then a Reactive Ion Etching (RIE) process is carried out, so that a high-quality graphene wall channel and a photoconductive detector based on graphene wall/silicon composite are realized. The graphene walls and silicon form schottky barriers that separate the photo-generated electron-hole pairs. The holes enter the graphene wall channel, and high optical response gain can be realized by utilizing a photo-induced gate control effect.)

1. A preparation method of a photoelectric detector based on a graphene wall/silicon composite heterojunction is characterized by comprising the following steps:

s1: placing the silicon substrate in H₂Carrying out high-temperature annealing;

s2: growing a graphene wall on a silicon substrate under certain pressure by using RF-PECVD; meanwhile, turning on the radio frequency, and setting the radio frequency power;

s3: after the graphene wall is grown, spin-coating two layers of photoresist on the graphene wall, and exposing an electrode pattern by using a photoetching method;

s4: depositing Cr and Au films on the graphene wall in sequence by using electron beam evaporation;

s5: patterning the device by a stripping process, namely sequentially placing a sample in acetone and AZ400 to remove two layers of used photoresist;

s6: setting the radio frequency power and the gas flow rate for the RIE etching machine to carry out patterning on the sample.

2. A photodetector prepared by the method of claim 1.

Technical Field

The invention belongs to the technical field of photoelectric detectors, and particularly relates to a photoelectric detector based on a graphene wall/silicon composite heterojunction and a preparation method thereof.

Background

At present, photon type detectors are all photovoltaic type photoelectric detection, while photoconductive detectors based on graphene wall/silicon heterojunction have not been reported, one reason is that the preparation process of photoconductive devices is relatively complex, so that the research on the photoelectric detection mechanism of graphene wall/silicon heterojunction is lacked at present.

Disclosure of Invention

Aiming at the prior art, the invention provides a photoelectric detector based on a graphene wall/silicon composite heterojunction and a preparation method thereof.

In order to achieve the purpose, the invention adopts the technical scheme that: the utility model provides a photoelectric detector based on graphite alkene wall/silicon composite heterojunction and its preparation method, the preparation method specifically is:

graphene walls were grown using RF-PECVD at a certain pressure. (before growth, the silicon substrate is annealed at high temperature in H2 to grow the graphene nanowalls better.

After the graphene wall growth is completed, two layers of photoresist are spin-coated on the graphene wall, and the electrode pattern is exposed by using a photoetching method. Then, Cr and Au films were sequentially deposited on the graphene walls using electron beam evaporation. The device is then patterned by a lift-off process, i.e. the sample is placed in sequence in acetone and AZ400 to remove the two layers of used photoresist. And finally, setting the radio frequency power and the gas flow rate for the RIE etching machine to carry out patterning on the sample.

The invention has the beneficial effects that: the preparation of the photoelectric detector based on the graphene wall/silicon composite heterojunction avoids the transfer process of materials and prevents other chemical impurities from entering. And simultaneously, the graphene wall photoconductive channel patterning process is overcome. Finally, the photo-induced gate control effect of the photoconductive graphene wall/silicon heterojunction is disclosed, and a new development opportunity is provided for the graphene wall/semiconductor heterojunction.

Drawings

FIG. 1 is an SEM image of a photodetector;

FIG. 2 is a plan cross-sectional view of the device;

FIG. 3 is an n-si band diagram;

FIG. 4 shows the application of an external bias V_DSIn the case ofNext, working process of the device;

FIG. 5 shows the variation of current within the device;

FIG. 6 shows the photoelectric gain phenomenon of the device;

fig. 7 shows the recombination process of holes and electrons in the device.

Detailed Description

The following examples are provided to illustrate specific embodiments of the present invention.