Photodetector and preparation method based on graphene/boron-doped silicon quantum dots/silicon

Abstract

The invention discloses a photoelectric detector based on graphene / boron-doped silicon quantum dots / silicon and a preparation method thereof. The photoelectric detector comprises an n type silicon substrate, a top electrode, a graphene film, a boron-doped silicon quantum dot film, and a bottom electrode. The photoelectric detector can carry out wide spectral detection, and a problem of low infrared detection response of a traditional silicon-based PIN junction is solved. According to the detector, graphene is used as an active layer and a transparent electrode, a dead layer is eliminated, and the absorption of incident light is enhanced. The boron-doped silicon quantum dot film is in the middle, the influence of a silicon surface state is reduced, and the reverse saturation current is suppressed at the same time. Under a certain reverse bias voltage effect, collision ionization is generated by photon-generated carriers and silicon lattice, and a high photoelectric response is obtained. The photoelectric detector and the preparation method have the advantages of a simple preparation process, low cost, a high response degree, fast response speed, a large internal gain, a small switching ratio, and easy integration.

Description

technical field

[0001] The invention belongs to the technical field of photodetection, relates to a photodetector device structure, in particular to a graphene / boron-doped silicon quantum dot / silicon-based photodetector and a preparation method. Background technique

[0002] Optical detectors have a wide range of applications in chemical material analysis, medical and health care, and space technology. Photodetectors have the advantages of high sensitivity, high optical response, and fast response speed, and have important applications in high-speed modulation and weak signal monitoring. Traditional silicon-based PIN junction detectors require thermal diffusion or ion implantation processes, and have almost no absorption of infrared light, so the response in the infrared band decreases rapidly or even becomes zero as the wavelength of the incident light increases. Therefore, there is a need to improve the response of silicon photodetection devices to long-wavelength infrare...

Examples

Embodiment Construction

[0029] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0030] Graphene / silicon Schottky junction is a commonly used device structure and has been reported in many optoelectronic devices. Boron-doped silicon quantum dots have absorption in the visible near-infrared and even mid-infrared, especially the mid-infrared has a strong absorption peak, there is a local plasmon effect (LSPR), the preparation process is simple, and it is widely used in the field of photoelectric detection. Since the boron-doped silicon quantum dot film is in contact with graphene, it will transfer charges to graphene, and it is also an anti-reflection film to reduce surface recombination, which can solve the dead layer problem and improve infrared optical response. A thin layer of boron-doped silicon quantum dots is added to graphene and silicon. On the one hand, the strong absorption of boron-doped silicon quantum dots in the infrare...

technical field

[0001] The invention belongs to the technical field of photodetection, relates to a photodetector device structure, in particular to a graphene / boron-doped silicon quantum dot / silicon-based photodetector and a preparation method. Background technique

[0002] Optical detectors have a wide range of applications in chemical material analysis, medical and health care, and space technology. Photodetectors have the advantages of high sensitivity, high optical response, and fast response speed, and have important applications in high-speed modulation and weak signal monitoring. Traditional silicon-based PIN junction detectors require thermal diffusion or ion implantation processes, and have almost no absorption of infrared light, so the response in the infrared band decreases rapidly or even becomes zero as the wavelength of the incident light increases. Therefore, there is a need to improve the response of silicon photodetection devices to long-wavelength infrare...

Examples

Embodiment Construction

[0029] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0030] Graphene / silicon Schottky junction is a commonly used device structure and has been reported in many optoelectronic devices. Boron-doped silicon quantum dots have absorption in the visible near-infrared and even mid-infrared, especially the mid-infrared has a strong absorption peak, there is a local plasmon effect (LSPR), the preparation process is simple, and it is widely used in the field of photoelectric detection. Since the boron-doped silicon quantum dot film is in contact with graphene, it will transfer charges to graphene, and it is also an anti-reflection film to reduce surface recombination, which can solve the dead layer problem and improve infrared optical response. A thin layer of boron-doped silicon quantum dots is added to graphene and silicon. On the one hand, the strong absorption of boron-doped silicon quantum dots in the infrare...

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